Rapid Visco Analyser (RVA) as a Tool for Measuring Starch-Related Physiochemical Properties in Cereals: a Review

Machine learning-combined hyperspectral imaging analysis for the non-destructive identification of wheat flours with varying gluten strengths

This study aimed to non-destructively identify wheat flours with different gluten strengths through the application of machine learning-combined hyperspectral imaging analysis. The performance of this approach was compared to conventional instrumental methods, specifically Mixolab, Fourier Transform Infrared (FTIR) spectroscopy, Rapid Visco-analyzer (RVA). The Mixolab measurement demonstrated that high values of mixing properties (water absorption, dough stability/development time) were observed in the order of the strong, medium, and weak flour samples. FTIR revealed the strong wheat flour with elevated peak intensities in the ranges of 1500-1700 and 2800-3500 cm-1, while the weak wheat had dominant peaks in the range of 800-1500 cm-1. The weak flour exhibited lower hyperspectral signal intensity, while the strong flour showed slightly higher intensity beyond 1395 nm. Linear discriminant analysis captured a significant dataset portion with two discriminants (≥99 %). Three machine learning models (decision tree, random forest, and k-nearest neighbor) achieved superb wheat flour classification with Mixolab features. For FTIR, RVA, and hyperspectral results, dimension-reduced datasets were generally more effective in classification than the original results. Furthermore, these prediction capabilities were verified by validating the models with independent datasets. This investigation demonstrates the potential of machine learning-combined hyperspectral analysis for the non-destructive identification of wheat flours, determining their suitability for specific food applications.

Factors improving dry fractionation of Bambara groundnut aiming at production of protein-rich ingredients with elevated nutritional and technological quality

Bambara groundnut is a nutritious African grain legume with potential to be refined into a high-protein ingredient. This work aimed to develop protein-rich ingredients from Bambara via dry processing. Due to Bambara's high fat content, two dry fractionation approaches were developed. In the first one, Bambara was defatted using supercritical CO2 extraction, milled and air classified producing ingredients with 48 % protein, achieving 74 % of total protein separation efficiency. Without defatting, the efficiency stood at 16.7 %. A second attempt, incorporating a flow aid during air classification, yielded ingredients with 38.2 % protein and protein separation efficiency of 33 %. These protein-rich ingredients exhibited higher protein solubility, total extractability, and water and oil absorption capacities compared to the raw materials. Phytic acid content increased in the protein-rich ingredients, but tannin was significantly reduced. The essential amino acid score of Bambara protein-rich ingredients was higher than 1 and the degree of protein hydrolysis was 31 %.

High pressure processing of glutinous rice starch complexed with Buddleja officinalis Maxim. Extract: Structural stability and digestibility improvements

This study investigated the impact of high pressure processing (HPP) on yellow glutinous rice starch (Y-GRS) formed by glutinous rice starch (GRS) complexed with Buddleja officinalis Maxim. extract (BOME). Y-GRS at 500 MPa achieved the highest complex index (0.506), indicating stronger starch-BOME interactions. Particle size analysis revealed that Y-GRS exhibited superior resistance to swelling, with D[4,3] increasing by 18.97 μm for Y-GRS and 31.64 μm for GRS as the pressure increased from 400 to 600 MPa. Y-GRS retained higher thermal stability, with an enthalpy change of 1.55 J/g at 500 MPa, compared with 0.83 J/g for GRS. The relative crystallinity of Y-GRS was 8.81 % higher than that of GRS. Structural analyses confirmed BOME mitigated higher pressure-induced damage to starch granule, preserving double helix and crystal structure. Rheologically, Y-GRS exhibited stable peak viscosity, weaker shear thinning behavior, and greater resistance to deformation than GRS. Following HPP, Y-GRS contained lower levels of rapidly digestible starch (RDS) and higher levels of resistant starch (RS) than GRS. In conclusion, these findings highlight HPP as a promising strategy for enhancing the functional properties of Y-GRS, offering improved stability and digestibility for starch-based food applications.

Effect of pullulanase treatment on the structural and in vitro digestive properties of starch-ovalbumin complexes

In this study, corn starch (CS) was debranched using pullulanase (PUL) and complexed with ovalbumin (OVA) under heat-moisture-treatment (HMT) conditions to investigate the physicochemical properties, structural properties and digestibility of corn starch-ovalbumin (CSOVA) complexes with different degrees of debranching. The results showed that PUL hydrolyzed the (1 → 6)-α glycosidic bonds to produce more linear chains as debranching time progressed, and these were able to form complexes between CSOVA complexes effectively. The combination of PUL and OVA treatment significantly changed the physicochemical properties of CS, as evidenced by the reduction in viscosity and swelling of the granules. In addition, the microscopic morphology of the CSOVA complexes gradually changed from small to large aggregates. After the addition of OVA and PUL treatment for 4 h, while X-ray diffraction (XRD) showed a crystallinity shift from A-type to B + V, with relative crystallinity decreasing from 19.45 % to 14.91 %. Fourier-transform infrared (FTIR) spectroscopy confirmed altered starch-protein interactions without new chemical bonds. In vitro digestion demonstrated resistant starch (RS) content increased to 45.6 % after 4 h of debranching. This study provides scientific evidence that the corn starch treated with PUL is a better source to form CSOVA complexes, providing a valuable slow-digesting starch.

Physiological and biochemical mechanisms of taste decrease in high tasting japonica rice under warming at growth stages

In order to better understand the response of the taste of high-tasting japonica rice in cool regions to climate warming, we have set up warming treatments at six growth stages in the field in two years: the before heading stage (T1), the whole growth stage (T2), the grain-filling stage (T3), the early grain-filling stage (T4), the middle grain-filling stage (T5) and the late grain-filling stage (T6). Except for T6, which showed no significant changes, all other treatments had varying degrees of negative effects on the taste value of milled rice, with T2 and T3 being the most serious, followed by T1, and finally T4 and T5. The taste value of milled rice was positively correlated with amylopectin content, total starch content, peak viscosity (PV), breakdown (BD), and negatively correlated with protein content, amylose content, hot pasting viscosity (HPV) and setback (SB). There was a close relationship between carbon and nitrogen metabolism of rice grains. The protein content was negatively correlated with the total starch content and amylopectin content, and positively correlated with the activity of glutamic oxalo-acetic transaminase (GOT) and glutamate pyruvate transaminase (GPT). The total starch content had no significant relationship with ADP-glucose pyrophosphorylase (AGPP) activity. The amylopectin content was positively correlated with soluble starch synthase (SSS) activity, and not significantly correlated with starch branching enzyme (SBE) and starch debranching enzyme (DBE) activity. The amylose starch content was positively correlated with granule-bound starch synthase (GBSS) activity and negatively correlated with SSS activity. Under warming conditions, the increase of nitrogen metabolism level promoted the increase of protein content and the decrease of amylopectin content in milled rice, leading to a decrease in taste quality.

Effects of psyllium polysaccharide with different molecular weights on the digestibility, physicochemical properties of rice starch, and interaction forces between them

The effects of psyllium polysaccharides (PP) with different molecular weights (Mw) on the physicochemical characteristics, interaction forces, and digestibility of rice starch (RS) are methodically examined in this work. High-Mw PP (H-PP) (3.83 × 106 Da), medium-Mw PP (M-PP) (8.39 × 104 Da), and low-Mw PP (L-PP) (9.28 × 103 Da) were fractionated, characterized, and added to RS to clarify their effect on starch digestion. The results indicate that H-PP exhibited the most pronounced inhibitory effect on enzymatic hydrolysis, leading to a significant reduction in the estimated glycemic index (eGI) by enhancing the crystalline structure and short-range molecular order of RS. Mechanistic investigation revealed that PP molecules interact with RS through hydrogen bonding and electrostatic interactions, forming a structural barrier that impedes enzymatic accessibility. The intensity of these interactions was greatest in RS-H-PP and gradually decreased in RS-M-PP and RS-L-PP, corresponding with an increase in starch digestibility. These findings provide mechanistic insights into the molecular interactions regulating polysaccharide-starch systems and establish a theoretical basis for the development of functional starch-based foods with controlled glycemic responses.

Towards a better understanding of the structure-function relationship of chestnut starches

Chestnut starch is of increasing interest for applications in foods but has been studied to a much lesser extent than other food starches. Hence, the structure-function relationships of starches isolated from eight chestnut cultivars were examined. The starch granules were round, oval and conical in shape, with average particle size and amylose content ranging between 7.14 and 9.39 μm and 29.9 to 34.0 %, respectively. Chain length distributions showed larger differences between the starches in the A chains than in the B1 ∼ B3 chains. All chestnut starches exhibited a typical B-type crystalline pattern, with the relative crystallinity ranging from 34.1 to 40.6 %. Significant differences were also observed in short-range molecular order and in functional properties. Pearson correlation analyses showed that amylose content was positively correlated with peak and breakdown viscosities and negatively correlated with the rate of in vitro digestion of the starches. The short A chains were negatively and the B2 or B3 chains positively correlated with the peak and breakdown viscosities, but the opposite correlations were noted for the rate of in vitro digestion of the starches. This study contributes new insights into an understanding the structure-function relationships of chestnut starches and for their applications in foods.

Effects of the addition of cassava starch and the size of water clusters on physicochemical and cooking properties of rice noodles

It is meaningful to explore the addition of additives and the structural characteristics of water on the quality of rice noodles. Herein, the effects of the addition of cassava starch and the size of water clusters on physicochemical and cooking properties of rice noodles were systematically studied. The addition of 25 % cassava starch effectively enhanced the swelling performance and textural properties of rice noodles. In comparison to non-activated water with large water clusters (LW), activated water with small water clusters (SW) significantly affected the interaction between water and starch molecules. Compared with LW-RN-25CS (rice noodles made with LW and 25 % cassava starch), SW-RN-25CS (rice noodles made with SW and 25 % cassava starch) presented better textural properties, including hardness, springiness, and adhesiveness. The rehydration time of SW-RN-25CS decreased from 12.31 ± 0.25 min (LW-RN-25CS) to 10.92 ± 0.46 min. This study provides reliable strategy and technology to produce high-quality rice noodles.

The effect of gelatinisation and enzymatic hydrolysis methods on the starch, sugar and physicochemical profiles of faba bean milk

This study aimed to address challenges of colloidal instability and undesirable sensory properties associated with starch in pulse-based dairy alternatives by investigating enzymatic starch hydrolysis in faba bean milk (FBM). The effects of gelatinisation temperature (60-95 °C) and enzymatic hydrolysis methods (including single enzyme with α-amylase and a multi-enzyme blend containing α-amylase, pullulanase, protease, cellulase, xylanase and lipase) were evaluated on starch and sugar profiles, micromorphology, and rheological properties of FBM. Unhydrolysed FBM exhibited a larger median particle size (114.58 μm), while enzyme-treated samples showed a reduction in particle sizes (38.53-67.63 μm). Both enzymatic treatments resulted in an 85-92 % reduction in starch content, with glucose and maltodextrin levels remaining consistent across different gelatinisation temperatures and hydrolysis variations. Hydrolysis also enhanced colloidal stability by reducing dry sediment (9.55 %) and sedimentation rate (4.69 %/hr) by approximately 45 % and 59 %, respectively. FBM hydrolysed with the multi-enzyme blend displayed lower viscosity (0.07 Pa.s) and consistency coefficient (0.28 Pa.sn) compared to the α-amylase treated samples, likely due to additional peptide breakdown. These findings suggest that a separate pre-gelatinisation stage is not essential for an effective hydrolysis of FBM starch as gelatinisation likely occurs concurrently with enzymatic treatment at 70 °C. Both single and multi-enzyme hydrolysis methods offer promising benefits for improving the sensory properties of FBM and warrant further exploration in future studies.

Impact of Some Processing Factors on the Pasting Properties of Poundo Flour Made From Precooked Sweet Potato Tubers

Understanding the impact of processing factors on the pasting properties of flour is critical for optimizing its quality, functionality, and suitability for various food applications. This study investigated the effect of three processing factors: slice thickness, precooking time, and drying temperature on the pasting properties of poundo flour made from precooked tuber crops (sweet potato) using a 3 × 5 central composite rotatable design. Pasting properties, including peak viscosity (PV), final viscosity (FV), trough viscosity (TV), setback viscosity (SBV), breakdown viscosity (BDV), and pasting time (Pt), were analyzed. The measured values ranged as follows: PV (192.46-281.36R V U $RVU$ ), FV (211.37-298.25R V U $RVU$ ), TV (75.3-99.37R V U $RVU$ ), BDV (114.03-195.99R V U $RVU$ ), SBV (116.09-210.97R V U $RVU$ ), and Pt (3.86-6.44  min ${\mathrm{min}}$ ). The coefficients of determination of the PV, FV, TV, BDV, SBV, and Pt were 0.96, 0.94, 0.80, 0.95, 0.93, and 0.78, respectively. High coefficients of determination indicated strong correlations between processing factors and pasting properties. Optimization aimed to maximize viscosities while minimizing Pt. Predicted optimum values of 281.36R V U $RVU$ (PV), 283.81R V U $RVU$ (FV), 90.90R V U $RVU$ (TV), 190.71R V U $RVU$ (BDV), 193.16R V U $RVU$ (SBV), and 4.54  min ${\mathrm{min}}$ (Pt) were obtained at 2.51  mm ${\mathrm{mm}}$ slice thickness, 21.38  min ${\mathrm{min}}$ precooking time, and 64.79°C drying temperature. This was experimentally validated to give corresponding values of 282.36R V U $RVU$ , 282.21R V U $RVU$ , 91.04R V U $RVU$ , 190.22R V U $RVU$ , 193.59R V U $RVU$ , and 4.46  min ${\mathrm{min}}$ , respectively. The developed models could be used to select any combination of the processing parameters that will suit the pasting properties of poundo flour made from precooked sweet potato tubers. PRACTICAL APPLICATION: By carefully controlling and understanding the processing factors that influence the pasting properties of poundo flour made from precooked sweet potato tubers, the food industry can create high-quality, versatile, and nutritious products that meet diverse consumer needs and preferences. For instance, understanding the pasting properties of poundo flour allows for the development of gluten-free breads, cakes, and other baked items. Another application is in the formulation of convenient, shelf-stable porridge or weaning foods for infants and young children. Additionally, the pasting properties of poundo flour could be leveraged in producing value-added sweet potato-based snacks or extruded products. Food manufacturers can optimize pasting properties to produce poundo flour with desirable consistency and texture to improve the final product quality, making it more appealing to consumers. Furthermore, food service providers can select poundo flour with specific pasting properties that best suit different recipes like soups, sauces, or doughs, enhancing the culinary experience.

Changes in Quality and Safety Indexes During Rice Harvest and Discussion on Drying Technology

This study investigated the effects of natural and mechanical drying on the quality and safety indices of newly harvested rice. The quality indices (moisture content, dry-basis 1000-grain weight, yellowing rate, gelatinization characteristics, and antioxidant enzyme activity) and safety indices (zearalenone, vomitoxin, and aflatoxin B1) were evaluated post-drying. The results demonstrated that natural drying significantly outperformed mechanical drying in terms of quality retention and antioxidant enzyme activity, particularly in preserving product integrity. In contrast, mechanical drying excelled in drying cost, speed, and process controllability. Using the Analytic Hierarchy Process (AHP), the quality and safety indices of rice dried by both methods were comprehensively assessed. The scoring results indicated that rice dried by natural methods had superior quality compared to that dried mechanically.

Physical modification of corn and potato starches using soaking, freezing, and drying

Effects of continuous soaking, freezing, and drying on physicochemical properties of corn and potato starches were investigated to prove potentials of sequential physical modification method. High temperature soaking showed the higher swelling power than low temperature soaking in both starches right after soaking. Freezing did not significantly rearrange the molecular structure of both starches. Drying greatly change the physicochemical properties of both starches in the order of freeze, air and spray dryings. Consequently, sequential treatment of soaking, freezing, and drying lowered RVA pasting characteristics (peak viscosity, breakdown, setback) as well as amylopectin melting transition temperature compared to native starch. Particularly, potato starch showed more significant change than corn starch, possibly due to the differences in water absorption, amylose content, crystallinity, granule size, etc. Overall, high temperature soaking and freeze drying significantly change the RVA, DSC and XRD characteristics in the sequential treatment of soaking, freezing and drying of starches.

Synergistic effect of ozone treatment with α-amylase on the modification of microstructure and paste properties of japonica rice starch

The objective was to evaluate the synergistic effect of ozonization and α-amylase on modifying the microstructure and paste properties of starch, using 0.00042 g of ozone/100 g of buffer for various durations. Enzymatic susceptibility was increased, achieving maximum values of 12.73 % with an 11.42 % increase in crystallinity and an average particle size of 10.12 μm for 90 min treated japonica rice starch (JR90). The granules exhibited a polyhedral shape and, with increased intensity of combined treatments, formed clusters and lost their original geometry. Apparent viscosity, rheological, and textural parameters were reduced due to the more efficient action of α-amylase on ozonized starch, as confirmed by the low gelatinization enthalpy value (7.61 J/g). Ozone proved effective in opening starch chains, partially gelatinizing granules, homogenizing the enzymatic medium, and increasing the hydrolysis rate of α-amylase in japonica rice starch.

Regulation of Rice Grain Quality by Exogenous Kinetin During Grain-Filling Period

Cytokinins (CKs) play important functions in plant growth and development and in response to adversity stress. However, little is known about the role CK plays in rice grain quality. We hypothesized that exogenous cytokinins could improve rice grain quality by regulating physiological traits and genes related to starch synthesis. Therefore, we exogenously applied different concentrations of kinetin (KT), an exogenous CK, during the grain-filling period. Our results show that all the different concentrations of exogenous KT treatments resulted in a significant increase in thousand-grain weight. In particular, chalkiness and chalky grain rate were significantly reduced, and gel consistency (GC) content and alkali spreading value (ASV) were significantly increased in 10-8 M KT treatment. Meanwhile, the exogenous application of 10-8 M KT positively affected the transcription of some starch synthesis-related genes, which was in contrast to the 10-5 M KT treatment. In conclusion, the exogenous application of appropriate concentrations of KT during the grain-filling period can ultimately affect rice grain quality by regulating the changes in the relevant indicators, such as appearance quality (AQ) and eating and cooking qualities (ECQ).

Mechanistic understanding of changes in physicochemical properties of different rice starches under high hydrostatic pressure treatment based on molecular and supramolecular structures

The molecular and supramolecular structures of japonica and waxy rice starches under high hydrostatic pressure treatment (450 MPa) were studied and the changes in physicochemical properties were analyzed based on these structures. The molecular structures of japonica and waxy rice starch cause differences in the lamellar structure and physicochemical properties. The thickness of amorphous lamella of japonica rice starch increased at 5 min (2.95 nm) followed by a gradual collapse of lamellar structure. Whereas the thickness of crystalline lamellae of waxy rice starch increased at 15 min (5.92 nm) and the lamellae collapsed suddenly at 20 min. The pasting, rheological and textural characteristics of both starches increased significantly within 10 to 15 min. The decreasing onset temperature and enthalpy of high hydrostatic pressure-treated starches indicated easier gelatinization. High hydrostatic pressure-treatment offers potential for developing starch-based products with low swelling capacity, easy gelatinization, high viscosity and hardness.

Impact of Ultrasonic-Assisted Preparation of Water Caltrop Starch-Lipid Complex: Structural and Physicochemical Properties

This study investigates the effect of ultrasonic-assisted preparation on the structural and physicochemical properties of water caltrop starch-palmitic acid complexes as a function of ultrasound intensity and treatment time. All samples exhibited the characteristic birefringence of starch-lipid complexes under the polarized microscope, and flake-like and irregular structure under scanning electron microscope (SEM), indicating the formation of complexes through ultrasonic-assisted preparation. X-ray diffraction pattern further confirmed the transition from the original A-type structure for native starch to V-type structure for starch-lipid complexes, and the relative crystallinity of starch-lipid complexes increased as the ultrasound intensity and treatment time increased. Attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR) analysis indicated a decreasing trend in absorbance ratio at wavenumber of 1022 cm-1/995 cm-1, suggesting that the increase in the complex promoted the self-assembly within the short-range ordered structure, leading to the formation of bonds between the complexes. However, rapid-visco analysis (RVA) demonstrated that the viscosity generally decreased as the ultrasound intensity and treatment time increased, possibly due to the reduction in molecular weight by ultrasound. Differential scanning calorimetric (DSC) analysis revealed that the control starch-lipid complex without ultrasound treatment (US-0-0) exhibited two distinct endothermic peaks above 90 °C, representing Type I (95-105 °C) and Type II (110-120 °C) V-type complexes. However, ultrasound-treated samples showed only one peak around 95-105 °C and increased enthalpy (∆H), which was likely due to the breakdown of amylose and amylopectin, leading to more complex formation with palmitic acid, while the resulting shorter chains in the ultrasound-modified sample favor the formation of Type I complexes.

Structural evolution of maize starches with different amylose content during pasting and gelation as evidenced by Rapid Visco Analyser

This study examined multi-scale structural alterations of maize starches varying in amylose content during pasting and gelation, using Rapid Visco Analyser (RVA). At 50 °C, starch granules maintained their morphology with low viscosity. As the temperature increased to 95 °C, helical and crystal structures were destroyed, leading to granule swelling, distortion and porosity, as identified by Wide Angle X-ray Scattering and Fourier Transforms Infrared measurements at 90% moisture. This resulted in increased viscosity and the formation of a loose gel network structure. Subsequently, maintaining the temperature at 95 °C caused a decrease in viscosity as most granules disappeared, forming a reorganized flaky gel structure with larger pores. As the temperature decreased, gel porosity reduced. In high amylose content starch, the viscosity remained low and granules were partially gelatinized since the heating temperature was below the gelatinization temperature. This study is the first to detail starch multilevel structural dynamics during RVA gelatinization.

Glutinous rice gel as all-natural ink supply for extrusion-based food 3D printing - the chemical basis of gel printability

In this study, four varieties of glutinous rice were screened out of 18 varieties as representative model inks. Gel prepared using variety WN9612 of high amylose content displayed high viscosity and large overall print deviation (OPD = 17.4 ± 0.4 %) due to difficulties in extrusion. Printed item by variety 19415 of medium amylose content showed good printability (OPD = 4.4 ± 0.4 %) and highest hardness (197.5 ± 7.3 N). Similarly good printability was demonstrated by variety 19416 (OPD = 4.1 ± 0.2 %) containing low amylose content but abundant protein and bound-water. Variety WN9446 lacking protein and moisture created item with fluid structure, lowest gel strength (738.5 ± 20.9 Pa) and standing ability. Therefore, low to medium amylose content rendered suitable viscosity, extrudability and printability of rice gel while non-starchy components predominated water mobility and texture of 3D printed items. This study for the first time establishes theoretical groundwork of selecting glutinous rice varieties with appropriate chemical composition as all-natural materials in 3D printing and food customization.

Investigating the Effects of Acid Hydrolysis on Physicochemical Properties of Quinoa and Faba Bean Starches as Compared to Cassava Starch

In response to the growing demand for high-quality food ingredients, starches from underutilised sources like quinoa and faba bean are gaining attention due to their unique properties and high tolerance to adverse environmental conditions. Acid hydrolysis is a well-established chemical method for producing modified starch with improved solubility, lower gelatinisation temperature, and reduced pasting viscosity. However, various outcomes can be achieved depending on the type of starch and modification conditions. This study comparatively investigated the effects of acid hydrolysis on the functional and physicochemical properties of emerging starches from quinoa and faba bean, with cassava starch serving as a reference from a leading source. The results demonstrated increased dietary fibre content across all three starches, with faba bean starch showing the most significant rise. Acid treatment also enhanced the crystallinity of the starches, with faba bean starch exhibiting the highest increase in relative crystallinity, which led to a shift towards higher temperatures in their thermal properties. Additionally, water solubility and oil adsorption capacity increased, while swelling power decreased following acid treatment. The acid treatment reduced the pasting properties of all samples, indicating that the modified starches were more resistant to heating and shearing in the rapid visco analyser. While quinoa starch gel remained soft after acid hydrolysis, the gel strength of cassava and faba bean starches improved significantly, making them suitable as plant-based gelling agents.

Prevent lumping during hot-water rehydration of lotus rhizome powder by restricted swelling treatment

Lotus rhizome powder (LRP) tends to lump during hot-water rehydration, adversely affecting its edible quality. By utilizing a restricted swelling treatment (ST), where LRP was swollen at a temperature slightly below its onset gelatinization temperature (To), the lumping rate could be substantially reduced from 30.95% to 6.39%. This treatment induced an ordered-disordered structural transition of LRP without compromising its granule morphology and water dispersibility. This transition led to significant increases in thermal transition temperatures and a notable delay in peak pasting time by 86.6 s. These changes effectively delayed the formation of a gelatinous skin surrounding the dry granules, allowing them sufficient time to absorb water and paste completely, thereby preventing lumping. The prevention of lumping was beneficial for obtaining desired viscoelasticity of LRP paste. Conversely, ST treatments conducted at temperatures markedly deviating from To resulted in significantly higher lumping rates, underscoring the importance of carefully controlling the ST temperature.

Sulfur affects multi-scale starch structures and its contribution to the cookie-baking quality of wheat subjected to shade stress

The components and structure of starch macromolecules critically determine its food-use properties. However, elemental sulfur supplementation affects the relationship between starch structure and the cookie-making quality of wheat under shaded environments remains unclear. Here, we investigated the effect of sulfur on the starch multi-scale structures and its contribution to the cookie-baking quality of wheat after pre- or post-anthesis shading. Compared with the unshaded control, shade stress decreased the amylose and total starch contents, formed smaller B-type starch granules, narrowed the molecular weight distribution, and decreased the amylopectin long-chain proportion, crystallinity, viscosity, and spread ratio of cookies. Weak-gluten cultivars are more sensitive to shade stress than strong-gluten cultivars. Under shaded environments, sulfur increased the amylopectin content, proportion of amylopectin short chains, and total starch content, increasing the mean diameter of starch granules and viscosity, ultimately decreasing the cookie hardness. The random forest model revealed that the surface area of the starch granules (18.7 %) and amylopectin B3 chain (6.7 %) contributed the most to the variation in the cookie spread ratio. Cookie hardness was determined mainly by the total starch (7.8 %), amylopectin (6.3 %), and trough viscosity (5.0 %). Our results help to design strategies for achieving superior-quality wheat in the context of global dimming.

Versatile Biopolymers for Advanced Lithium and Zinc Metal Batteries

Lithium (Li) and zinc (Zn) metals are emerging as promising anode materials for next-generation rechargeable metal batteries due to their excellent electronic conductivity and high theoretical capacities. However, issues such as uneven metal ion deposition and uncontrolled dendrite growth result in poor electrochemical stability, limited cycle life, and rapid capacity decay. Biopolymers, recognized for their abundance, cost-effectiveness, biodegradability, tunable structures, and adjustable properties, offer a compelling solution to these challenges. This review systematically and comprehensively examines biopolymers and their protective mechanisms for Li and Zn metal anodes. It begins with an overview of biopolymers, detailing key types, their structures, and properties. The review then explores recent advancements in the application of biopolymers as artificial solid electrolyte interphases, electrolyte additives, separators, and solid-state electrolytes, emphasizing how their structural properties enhance protection mechanisms and improve electrochemical performance. Finally, perspectives on current challenges and future research directions in this evolving field are provided.

Dynamic development of changes in multi-scale structure during grain filling affect gelatinization properties of rice starch

Rice was collected over the entire grain filling period (about 40 days) to explore the multi-structure evolution and gelatinization behavior changes of starch. During the early stage (DAA 6-14), the significant reduction in lamellar repeat distance (10.04 to 9.68 nm) and relative crystallinity (26.6 % to 22.7 %) was due to initial rapid accumulation of amylose (from 9.38 % to 14.05 %) and short amylopectin chains. Meanwhile, the decreased proportion of aggregation structure resulted in a decrease in the gelatinization temperature and a narrowed range of gelatinization temperature also indicated an increase in homogeneity as starch matured. Gelatinization enthalpy was mainly controlled by aggregation structure, which was negatively and positively related to the amylose content and the degree of order respectively. Peak viscosity of starch pasting increased and reached a maximum (924 cP) at DAA-21 due to larger granule size. Amylose and short amylopectin chains with degree of polymerization 6-12 showed positive and negative correlation with short-term retrogradation ability (setback value) respectively. The dynamics of different scale structure during grain filling had varying degrees of impact on gelatinization properties.

Effect of the Autoclaving-Cooling Cycle on the Chemical, Morphological, Color, and Pasting Properties of Foxtail Millet Starch

This study investigated the effect of the autoclaving-cooling (AC) cycle and the starch-to-water ratio on the chemical, morphological, color, and pasting properties of foxtail millet starch to improve its utilization in the food industry. Starch suspensions were prepared using different starch-to-water ratios (i.e., 1:1 and 1:4), with one to three AC cycles for each ratio. Subsequently, the chemical, morphological, color, and pasting properties of native and autoclaved-cooled foxtail millet starch (ACFS) were determined. The results showed that ACFS had higher overall resistant starch (RS) content than native starch. AC treatment reduced the lightness and whiteness index, gelatinization time, and pasting temperature while increasing particle sizes with irregular shapes and surfaces. Starch treated with distilled water at a 1:1 ratio with two AC cycles (1:1-2C) exhibited the highest amylose, starch, and RS contents with stable pasting properties compared with that in other AC treatments. Pasting stability was indicated by the low breakdown viscosity and high trough and final viscosity. The findings suggest that ACFS treated with 1:1-2C could be a stabilizer and functional food.

Optimizing planting density enhances the multi-scale structural characteristics and in vitro digestibility of maize starch via modulating the size distribution of granules

The modification of starch through agricultural practices is becoming increasingly significant for producing healthy foodstuffs and raw materials for industrial applications, consequently gaining momentum in academic research. This study examined how three different planting densities influenced the distribution of granule sizes, multi-scale structural characteristics, and in vitro digestibility of maize starch. The results showed that planting density significantly enhanced grain yield and relative crystallinity, and significant increases were also observed in the contents of both rapidly and slowly digestible starch. The surface- and volume-weighted mean diameter of granules significantly increased under the medium level (6.75 × 104 plants ha-1), and then decreased under high planting density level. As planting density level increased, the amylose content, peak viscosity, and hardness varied from 23.3 to 26.4 %, from 1962 to 2659 mPa·s, and from 129.3 to 307.6 g, respectively. However, no change was found in crystalline structure of maize starch. These results indicated that optimizing planting density could effectively improve grain yield and starch characteristics of maize, with the best effect under the level of 6.75 × 104 plants ha-1.

Changes in structure, physicochemical properties and in vitro digestibility of quinoa starch during heat moisture treatment with hydrogen-infused and plasma-activated waters

In this study, comparative effect of heat moisture treatment (HMT) with distilled, hydrogen-infused and plasma-activated waters on the structure, physicochemical properties and in vitro digestibility of quinoa starch (QS) was investigated. To our knowledge, this study is the first to apply hydrogen-infused water to starch modification. The surface of HMT-modified samples was much rougher than that of native QS. HMT did not change the typical "A"-type X-ray diffraction pattern of QS but it increased its relative crystallinity. Meanwhile, amylose content, gelatinization temperature and water absorption capacity of QS significantly increased, whereas viscosity and swelling power markedly decreased. The rapidly digestible starch level of HMT-treated samples was significantly lower than that of native QS, and the resistant starch content markedly increased. These alterations were dependent on treatment moisture level. Furthermore, compared to distilled water, the HMT with hydrogen-infused and plasma-activated waters induced much more extensive effect on above properties, and the sample treated with plasma-activated water had the highest extent due to the acidic or alkaline environment and reactive oxygen and nitrogen species. These results identified that the combination of HMT with hydrogen-infused or plasma-activated water was a novel strategy to improve the thermal stability and functionality of quinoa starch.

Physicochemical properties of starch of four varieties of native potatoes

The limited industrial use of indigenous varieties of native potatoes has caused a decrease in its cultivation, restricting it to the self-consumption of the Andean population. The present study analyzed the physicochemical, thermal, and structural properties of the starches extracted from four of these varieties Aq'hu Pukucho, Yurakk Kkachun Wakkachi, Yurac Anca, and Huarmi Mallco, as a potential source of be used in industries such as food, pharmaceutical and, bioplastics. The percentage yield in wet extraction ranged between 14.53 and 20.26 %. The luminosity L* and whiteness index (WI) values were observed in ranges of 90.75-92.71 and 90.05-91.50, respectively. The Finding revealed various techno-functional properties, since the level of amylose varied between 36.29 and 43.97 %, an average zeta potential of -22 mV, and a maximum viscosity between 19,450-14,583 cP. The starches showed consistent thermal behavior since the TGA curves showed three stages with gelatinization temperatures that ranged between 54.9 and 59.75 °C, an enthalpy of 3.60-6.62 J/g, and various shapes of particles such as circular, elliptical, and oval. In conclusion, the relationships between variables such as water absorption index, swelling power, viscosity, crystallinity, enthalpy, and gelatinization temperature reveal different characteristics of each type of starch, which can influence its use.

Ingredient Functionality of Soy, Chickpea, and Pea Protein before and after Dry Heat Pretreatment and Low Moisture Extrusion

This study investigates the impact of dry heat pretreatment on the functionality of soy, chickpea, and pea protein ingredients for use in texturized vegetable protein (TVP) production via low moisture extrusion. The protein powders were heat-treated at temperatures ranging from 80 °C to 160 °C to modulate the extent of protein denaturation and assess their effects on RVA pasting behavior, water absorption capacity (WAC), and color attributes. The results indicate that the pretreatment temperature significantly influenced the proteins' functional properties, with an optimal temperature of 120 °C enhancing pasting properties and maintaining WAC, while a higher pretreatment temperature of 160 °C led to diminished ingredient functionality. Different protein sources exhibited distinct responses to heat pretreatment. The subsequent extrusion processing revealed significant changes in extrudate density and color, with increased density and darkness observed at higher pretreatment temperatures. This research provides insights into the interplay between protein sources, pretreatment conditions, and extrusion outcomes, highlighting the importance of controlled protein denaturation for developing high-quality, plant-based meat analogues. The findings have broad implications for the optimization of meat analogue manufacturing, with the aim of enhancing the sensory experience and sustainability of plant-based foods.

Sourdough Bread Quality: Facts and Factors

The term "sourdough" denotes a dough composed of flour and water, fermented through the action of yeast and lactic acid bacteria. The utilization of sourdough fermentation technology can enhance the nutritional attributes of bread made from wheat grain. In recent times, sourdough bread has experienced a resurgence, fueled by growing consumer demand for healthier bread options. The market dynamics for sourdough illustrate its rapid expansion and significant role in the contemporary food industry. Sourdough fermentation improves nutritional qualities by altering the structure and function of proteins and starch, enhancing dietary fiber, volatile compound profiles, and antioxidant activity, and reducing FODMAPs. The quality of sourdough bread is influenced by several factors, including fermentation environment, flour particle size, protein quality, starch characteristics, and dietary fiber composition. Moreover, the incorporation of alternative grains (intermediate wheatgrass and legume flour) and non-flour ingredients (fruits, herbs, and dairy products) presents opportunities for creating sourdough bread with unique sensory and nutritional profiles. This review offers updated insights on the quality aspects of sourdough fermentation, the factors that influence the effectiveness of the sourdough fermentation process, sourdough technology with unconventional and non-flour ingredients, and the potential market for frozen sourdough, considering its convenience and extended shelf life.

Exploring effect of uniform dry ball-milling duration on pasting and rheological properties of pink potato and maize starch mixtures

This study examined the potential effect of ball milling on maize starch (MS), pink potato starch (PPS), and their blends in various ratios (90:10, 80:20, and 70:30) on the pasting and rheological properties. Ball-milling led to changes in the particle size, ranging from 652.9 to 6488 nm, and a decrease in relative crystallinity (RC), as confirmed by XRD. Ball-milling increased amylose concentration in blend with the ratio of 90:10 up to 32.53 %, indicating structural alterations and molecular interactions. FESEM analysis confirms significant changes in the surface and particle sizes and starch gels with honeycomb structures. FTIR and Raman spectroscopy revealed a decrease in the intensity of the 1044 cm-1 and 480 cm-1 bands, respectively, signifying structural changes. Pasting parameters like peak viscosity and gelatinization behavior varied with PPS incorporation. The 80:20 blend had the highest viscosity, demonstrating PPS's capacity for high-viscosity starch paste. Rheological measurements of starch blends exhibited shear-thinning behavior, whereas the viscoelastic properties of the blends are influenced by particle size and the ratio of pink potato starch. Ball-milling treatment affects the granules and causes molecular-level interactions between the particles. This results in unique rheological properties of the starch blends, making them suitable for various applications.

Analysis of the impact of drying on common wheat quality and safety

Mycotoxin contamination in grain has been an ongoing concern in the world. Wheat, as a staple crop in China, is particularly notable for its mycotoxin contamination. The main mycotoxins in wheat include deoxynivalenol (DON) and its derivates, zearalenone (ZEN) and aflatoxin B1 (AFB1). After harvest, drying process is an effective technique and a necessary step to ensure the long-term safe storage of wheat. In this study, the moisture content, the concentrations of total fungi and main mycotoxins in post-harvest wheat of three wheat growing areas in the North China Plain were examined, and the effect of different drying methods on wheat quality was evaluated. The results showed that 87.5% of wheat samples were simultaneously contaminated with two or more mycotoxins. Due to the pre-harvest heavy rainfall, the moisture content, the levels of total fungi and mycotoxins in wheat samples of Liaocheng city were significantly higher compared to other regions. Moreover, the effects of different drying methods on the starch gelatinization and viscosity properties of wheat were investigated. The results showed that both natural air drying and dryer drying altered the crystal structure within starch particles and affected the gelatinization and viscosity properties of wheat starch. However, there is no significant difference between the wheat samples treated with two drying methods.

Structure-function relationship of oat flour fractions when blended with wheat flour: Instrumental and nutritional quality characterization of resulting breads

The present work investigated the structure-function relationship of dry fractionated oat flour (DFOF) as a techno-functional ingredient using bread as a model system. Mechanically, DFOF fractions (F), that is, F1: <224 µm, F2: 250-280 µm, F3: 280-500 µm, F4: 500-600 µm, and whole oat flour (F5) were blended with white wheat flour at 10%, 30%, and 50% substitution levels for bread making. The blended flours, doughs, and bread samples were assessed for their techno-functional, nutritional, and structural characteristics. The results of Mixolab and the Rapid Visco Analyzer show that the 50% substituted F3 fraction exhibits the highest water absorption properties (69.53%), whereas the 50% F1 fraction exhibits the highest peak viscosity of the past slurry. Analysis of bread samples revealed a lower particle size of DFOF fractions and higher supplementation levels, increased β-glucan levels (0.13-1.29 g/100 bread (db), reduced fermentable monosaccharides, that is, glucose (1.44-0.33 g/100 g), and fructose (1.06-0.28 g/100 g). The effect of particle size surpassed the substitution level effect on bread volume reduction. The lowest hardness value for F1 is 10%, and the highest value for F2 is 50%. The total number of cells in the bread slice decreased from the control to the F4 fraction (50%). Multi-criteria analysis indicated that DFOF fractions produced breads with similar structure and higher nutritional value developed from white wheat flour. PRACTICAL APPLICATION: The use of mechanically fractionated oat flours fractions in white wheat flour breads can improve the nutritional profile without affecting the physical properties of the bread product. Based on the oat flour fractions, bakers and food processing companies can tailor the bread formulations for high β-glucan, high fiber, and low reduced sugar claims.

Appearance, components, pasting, and thermal characteristics of chalky grains of rice varieties with varying protein content

This study investigated two rice varieties, GuichaoII and Jiazao311, with distinct protein content to determine the variation in appearance, components, pasting, and thermal properties of rice with different chalkiness degrees. Grain length, width, head rice weight, and whiteness of both varieties markedly increased as chalkiness increased from 0% to 50%. However, the variation in components, pasting, and thermal characteristics of chalky grain substantially differed between the rice varieties. The protein content of GuichaoII (low protein content) significantly increased with the chalkiness degree, along with a significant increase in onset, peak, and conclusion temperatures and gelatinization enthalpy. In Jiazao311 (high protein content), the chalkiness degree increased with the protein content but decreased with the starch content, along with increased trough, final, setback, and consistency viscosities. Compared to amylose content, protein content had a greater influence on the thermal properties and pasting characteristics of chalky grains of GuichaoII and Jiazao311, respectively.

Effect of dynamic high-pressure treatments on the multi-level structure of starch macromolecule and their techno-functional properties: A review

Over the past decades, dynamic high-pressure treatment (DHPT) executed by high-pressure homogenization (HPH) or microfluidization (DHPM) technology has received humongous research attention for starch macromolecule modification. However, the studies on starch multi-level structure alterations by DHPT have received inadequate attention. Furthermore, no review comprehensively covers all aspects of DHPT, explicitly addressing the combined effects of both technologies (HPH or DHPM) on starch's structural and functional characteristics. Hence, this review focused on recent advancements concerning the influences of DHPT on the starch multi-level structure and techno-functional properties. Intense mechanical actions induced by DHPT, such as high shear and impact forces, hydrodynamic cavitation, instantaneous pressure drops, and turbulence, altered the multi-level structure of starch for a short duration. The DHPT reduces the starch molecular weight and degree of branching, destroys short-range ordered and long-range crystalline structure, and degrades lamellar structure, resulting in partial gelatinization of starch granules. These structural changes influenced their techno-functional properties like swelling power and solubility, freeze-thaw stability, emulsifying properties, retrogradation rate, thermal properties, rheological and pasting, and digestibility. Processing conditions such as pressure level, the number of passes, inlet temperature, chamber geometry used, starch types, and their concentration may influence the above changes. Moreover, dynamic high-pressure treatment could form starch-fatty acids/polyphenol complexes. Finally, we discuss the food system applications of DHPT-treated starches and flours, and some limitations.

Starch spectra of Ampelopteris prolifera (Retz.) Copel, a new addition to the existing lexicon and its comparison with a local potato cultivar (Solanum tuberosum L. cv. Kufri Jyoti)

Novel kinds of starch spectra were generated from a lesser-known plant, making this investigation unique. The recent trend of starch characterization shows the establishment of novel bioresources from nonconventional unexplored databases. The present endeavor was made to obtain the starch fingerprint of Ampelopteris prolifera (rhizome) belonging to seedless vascular plants. For comparison, a commercial local cultivar of potato (Kufri Jyoti) was taken. The starch particle of A. prolifera shows much uniqueness depicting its novelty viz., crystallinity index of 60.04 %, powder diffractogram at (2θ scale)17.57° to 39.78°; this diffractogram pattern is reported from this study as newer one i.e. R type(whereas potato starch is CB type); characteristic peak at 2θ = 20.07° suggests starch-lipid complex formation and V type crystallinity (i.e. RS 5 type); FTIR spectra showing the presence of more short chain branching; high gelatinization temperature(84.62 ± 0.10), particle size and zeta value of A. prolifera is 4.00 ± 0.81 μm and - 18.91 ± 3.58 mV respectively. Bragg's peak from the single crystal X-ray diffraction has been generated for the first time of A. prolifera. Extraction of the starch particle was performed in chilled water. Therefore, the present study suggests wide-spectrum commercial utility and cost-effective production.

Impact of cyclic and continuous dry heat modification on the structural, thermal, technological, and in vitro digestibility properties of potato starch (Solanum tuberosum L.): A comparative study

Dry heat treatment (DHT) has been demonstrated as a viable method for starch modification, offering benefits due to its environmentally friendly process and low operational costs. This research modified potato starch using different DHT conditions (continuous-CDHT and cyclic-RDHT), with durations ranging from 3 to 15 h and 1 to 5 cycles, at 120 °C. The study investigated and compared the structural, thermal, pasting, and morphological properties of the treated samples to those of untreated potato starch, including in vitro digestibility post-modification. DHT altered the amylose content of the biopolymer. X-ray diffraction patterns transitioned from type B to type C, and a decrease in relative crystallinity (RC%) was observed. Morphological changes were more pronounced in starches modified by RDHT. Paste viscosities of both CDHT and RDHT-treated starches decreased significantly, by 61.7 % and 58.1 % respectively, compared to native starch. The gelatinization enthalpy of RDHT-treated starches reduced notably, from 17.60 to 16.10 J g-1. Additionally, starch digestibility was impacted, with cyclic treatments yielding a significant increase in resistant starch content, notably an 18.26 % rise. These findings underscore the efficacy of dry heat in enhancing the functional properties of potato starch.

The effect of lactic acid bacteria fermentation on physicochemical properties of starch from fermented proso millet flour

A waxy and a non-waxy proso millet flour were each fermented by Lactobacillus amylovorus, Lactobacillus fermentum, and Lactobacillus plantarum. The samples were fermented for one to five days, and starch was isolated from the fermented flours. The pH of fermented proso millet flour ranged from 3.27 to 3.6. The starch morphology of fermented samples differed from that of raw starches, with surface indentations and small pores leading to granule channels observed on the granule. The gelatinization temperatures were significantly decreased, whereas the enthalpies were not affected by fermentation. Peak and final viscosities were decreased after fermentation. The hardness of Lb. fermentum and Lb. plantarum fermented waxy starch gels was decreased, but the non-waxy samples fermented by Lb. amylovorus had significantly increased hardness. The adhesiveness of the starch gels from fermented samples was significantly increased. Lactic acid fermentation had significant effects on the morphology and physicochemical properties of proso millet starch.

New Insight into the Effects of Endogenous Protein and Lipids on the Enzymatic Digestion of Starch in Sorghum Flour

The effects of endogenous lipids and protein in sorghum flour on starch digestion were studied following the depletion of lipids and/or protein and after the reconstitution of separated fractions. The removal of protein or lipids moderately increases the digestibility of starch in raw (uncooked) sorghum flour to values close to those for purified starch. Rapid Visco Analyzer data (as a model for the cooking process) show that cooked sorghum flours with lipids have a lower starch digestibility than those without lipids after RVA processing, due to the formation of starch-lipid complexes as evidenced by their higher final viscosity and larger enthalpy changes. Additionally, the formation of a starch-lipid-protein ternary complex was identified in cooked sorghum flour, rather than in a reconstituted ternary mixture, according to the unique cooling stage viscosity peak and a greater enthalpy of lipid complexes. After heating, the sorghum flour showed a lower digestibility than the depleted flours and the reconstituted flours. The results indicate that the natural organization of components in sorghum flour is an important factor in facilitating the interactions between starch, lipids, and protein during RVA processing and, in turn, reducing the starch digestion.

Effects of Ugali Maize Flour Fortification with Chia Seeds (Salvia hispanica L.) on Its Physico-Chemical Properties and Consumer Acceptability

The study investigated the effect of incorporating whole chia seeds (WCS) and defatted chia seed flour (DCF) into whole maize meal for ugali preparation. Both were incorporated at substitution levels of 3%, 6%, and 9% separately, and the resulting treatments subjected to laboratory analysis. In addition, ugali samples were prepared from all the resulting flour formulations and subjected to consumer acceptability assessment. Incorporation of both DCF and WCS resulted in increased water absorption capacity (ranging from 0.78 to 0.98 g/mL), swelling index (ranging from 0.15 to 3.25 mL/g), and swelling capacity (ranging from 2.46 to 5.74 g/g). WCS decreased the bulk density and oil absorption capacity. DCF, however, resulted in an increase in bulk density and oil absorption capacity. Both DCF and WCS lowered the lightness (L*) of the products. Proximate composition ranged from 4.78 to 7.46% for crude fat, 7.22% to 9.16% for crude protein, and 1.74 to 4.27% for crude fiber. The obtained results show the potential of chia seeds as a good fortificant of maize flour since it resulted in nutritionally superior products (crude ash, crude protein, crude fat, and energy value) when compared to control. The freshly prepared ugali samples were generally acceptable to the panelists up to 9% WCS and 6% DCF substitution levels.

Effects of elevated atmospheric [CO2] on grain starch characteristics in different specialized wheat

The increasing atmospheric [CO2] poses great challenges to wheat production. Currently, the response of starch characteristics in different specialized wheat cultivars to elevated [CO2], as well as the underlying physiological and molecular mechanisms remains unclear. Therefore, an experiment was conducted with open-top chambers to study the effects of ambient [CO2] [a(CO2)] and elevated [CO2] [e(CO2)] on photosynthetic performance, yield and starch characteristics of bread wheat (Zhengmai 369, ZM369) and biscuit wheat (Yangmai 15, YM15) from 2020 to 2022. The results demonstrated a significant improvement in photosynthetic performance, yield, amylose and amylopectin content, volume ratio of large granules under e[CO2]. Moreover, e[CO2] upregulated the gene expression and enzyme activities of GBSS (Granule-bound starch synthase) and SSS (Soluble starch synthase), increased starch pasting viscosity, gelatinization enthalpy and crystallinity. Compared to YM15, ZM369 exhibited a higher upregulation of GBSSI, greater increase in amylose content and volume ratio of large granules, as well as higher gelatinization enthalpy and crystallinity. However, ZM369 showed a lower increase in amylopectin content and a lower upregulation of SSSI and SSSII. Correlation analysis revealed amylose and amylopectin content had a positive correlation with GBSS and SSS, respectively, a significant positively correlation among the amylose and amylopectin content, starch granule volume, and pasting properties. In conclusion, these changes may enhance the utilization value of biscuit wheat but exhibit an opposite effect on bread wheat. The results provide a basis for selecting suitable wheat cultivars and ensuring food security under future climate change conditions.

An Impact Assessment of Par-Baking and Storage on the Quality of Wheat, Whole Wheat, and Whole Rye Breads

Par-baking technology increases the production efficiency of bread. However, the degree of par-baking can vary significantly amongst product types and intended sales markets, leading to substantial differences in the quality attributes of the finished product. The objective of this study was to explore the impact of the degree of par-baking on the technological quality of wheat, whole wheat, and whole rye bread (95, 75, and 50% of full baking time). More specifically, this study focused on the starch pasting behavior of different flour formulations, the crumb core temperature during par-baking, and the influence of the degree of par-baking on the bread characteristics of (composite) wheat bread as a function of storage time. The quality attributes of par-baked bread (0 and 4 days after par-baking) and fully baked bread (0 and 2 days after full baking) were assessed. A reduction in the degree of par-baking from 95 to 50% resulted over time in 19.4% less hardening and 8.6% more cohesiveness for the re-baked wheat breads. Nevertheless, it also negatively impacted springiness (-9.1%) and adhesion (+475%). It is concluded that using the core temperature to define the degree of par-baking is not sufficient for bread loaves intended to be consumed over time, but the results indicate that reducing the degree of par-baking can be beneficial for certain quality aspects of the breads.

Unlocking the potential of pasting properties to predict extrudate characteristics of corn grits blends with high amylose corn starch, potato starch, or rice flour

The development of new production lines of extruded ready-to-eat (RTE) snacks often results in high losses of edible food due to the trial-and-error approach in industry. Being able to predict extrudate characteristics of new formulations before having to run trials on industrial scale would be beneficial for reducing waste and having a more efficient development process. With this study, the correlation between pasting properties of seven blends of flours/starches and extrudate characteristics was investigated (100% corn grits, 25% and 50% replacement of corn grits with high amylose starch, potato starch, and rice flour). The predictive power of pasting characteristics on extrudate's moisture content, water absorption and solubility index, sectional expansion index (SEI) and hardness was studied. Results indicated the potential of predicting SEI, water solubility index (WSI), and water absorption index (WAI) of RTE-snacks. WSI and WAI were, respectively, negatively correlated with peak temperature (R2  = 0.897), and positively with peak temperature and positively with trough viscosity (R2  = 0.855). One can conclude that the rheometer can be a useful tool to gain insight into the characteristics of the extrudate, although further research with enlargement of the dataset is necessary to make the rheometer effectively deployable for potentially other extrudate characteristics.

Characteristics of rice starches modified by single and dual heat moisture and osmotic pressure treatments

The effect of osmotic pressure treatment (OPT), heat moisture treatment (HMT), and their dual combination as HMT-OPT and OPT-HMT on functional and pasting properties, gel texture, crystallinity, thermal, morphological, and rheological properties, and in vitro digestibility of modified starches were investigated. HMT was done with 29 % moisture at 111 °C for 45 min while OPT was performed at 117 °C for 35 min with saturated sodium sulphate solution. All modifications increased amylose content, improved pasting stability, and reduced swelling power and solubility. Dual modifications caused higher morphological changes than single modified starches. HMT and OPT increased pasting temperature, setback and final viscosity while decreased peak viscosity and breakdown, whereas HMT-OPT and OPT-HMT reduced all pasting parameters except pasting temperature. 1047/1022 and 995/1022 ratios and relative crystallinity decreased. V-type polymorphs were formed, and gelatinization temperature range increased with lower gelatinization enthalpy. Starch gel elasticity, RS and SDS content were enhanced to a greater extent after HMT-OPT and OPT-HMT. HMT as a single and dual form with OPT showed prominent effect on pasting, thermal, crystalline, and rheological properties. Application of HMT, OPT and dual modified starches with improved functionalities may be targeted for suitable food applications such as noodles.

Acidic water tempering and heat treatment, a hurdle approach to reduce wheat Salmonella load during tempering and its effects on flour quality

The cultivation and processing of wheat render it susceptible to microbial contamination from varied sources. Hence, pathogens such as Salmonella can contaminate wheat grains, which poses a food safety risk in wheat-based products. This risk is displayed by the incidence of foodborne illness outbreaks linked to Salmonella-contaminated wheat flour and flour-based products. The purpose of this study was to assess the effectiveness of combining acidic water and heat treatment in reducing the Salmonella load of hard red spring (HRS) wheat grains during tempering. Effective treatments were then evaluated for their effects on wheat flour quality. Tempering with sodium bisulfate (SBS), lactic acid (LA), and citric acid (CA) at 15% w/v alone reduced (p < 0.001) wheat Salmonella load by 3.15, 3.23, and 2.91 log CFU/g, respectively. Heat treatment (55 °C) reduced (p < 0.001) wheat Salmonellaload by 4.1 log CFU/g after 24 h of tempering. Combining both tempering and heat treatments resulted in a greater reduction in Salmonella load as non-detectable levels (<2 log CFU/g) of Salmonella in the wheat grains were obtained after 12 h of tempering with LA (15%) + heat. A similar result were achieved for both SBS (15%) + heat and CA (15%) + heat treatments after 18 h of tempering. Applying the combined treatments in HRS wheat grains resulted in comparable wheat flour baking (volume, texture, and crumb structure) and physicochemical properties (rheology and composition) relative to the control (tempering with water alone). The results from this study has the potential to be utilized for developing more effective methods for improving the food safety of wheat flour against Salmonella contamination.

Effect of wheat roasting conditions and wheat type on short-wave infrared (SWIR) spectral data of whole and milled wheat by ANOVA-simultaneous component analysis

ANOVA-simultaneous component analysis (ASCA) was used to investigate the effect of roasting and wheat type on shortwave-infrared (SWIR) spectra of whole wheat and flour through assessment of statistical significance and characterisation of the contributing spectral features. The full factorial experimental design included two wheat types, three roasting temperatures and three roasting frequencies. SWIR spectral images were collected from the two roasted wheat types and their two milled samples. Three ASCA models, one for each wheat conformation (kernel, whole wheat flour, white flour) were investigated. It was evidenced that all factors and interaction in the whole wheat flour model had a significant (p ≤ 0.05) effect on spectral data. Only the factor roasting frequency was not significant in white flour model and only the interaction between roasting frequency and wheat type was not significant for the kernel model. The main variations in the loading line plots were identified and characterised by chemical structural differences that occur within the sample. The effect of roasting frequency had a more adverse effect on protein stability, moisture evaporation, water soluble carbohydrates and aromatic amino acids, compared to roasting temperature. A Rapid Visco-Analyser (RVA) was used to further investigate difference in wheat type as almost all spectral data sets differed significantly. The most prominent difference between the two wheat types was observed as differences in amylase activity and presence of lipids. ASCA applied to SWIR whole wheat and flour spectral data effectively characterised the significant effect of roasting on wheat starch and protein structures.

Morphological, Structural, Thermal, Pasting, and Digestive Properties of Starches Isolated from Different Varieties of Rice: A Systematic Comparative Study

The aim of this study was to compare the properties of isolated starches from ten commonly consumed rice varieties in China and to investigate their possible association. In addition, principal component analysis (PCA) and correlation analysis were performed to demonstrate the weight or relevance of different properties. The starch granules had an irregular polyhedral structure. The crystalline structure had an orthogonal arrangement, which is characteristic of A-type starch with nanocrystals with an orthorhombic crystal structure. In addition, higher levels of rapidly digestible starch (72.43 to 74.32%) and resistant starch (2.27 to 2.3%) were found in glutinous rice starch. The highest content of slowly digestible starch (59.48%) was found in starch isolated from black rice, which may be an ideal rice variety for controlling blood glucose and weight. Starch isolated from red Hani terrace rice showed the highest thermal stability during cooking and the highest resistance to a high shear force treatment. In addition, the PCA suggests that the amylose content of starch largely determines the functional properties of starch and positively correlates with the peak viscosity and setback viscosity of the starch pasting. The results of this study will enrich the scientific knowledge of various rice starches and promote their application in the food industry and other industries.

High-pressure pasting performance and multilevel structures of short-term microwave-treated high-amylose maize starch

Microwave treatment is an environmentally friendly method for modification of high-amylose maize starch (HAMS). Here, the effects of short-time (≤120 s) microwave treatment on the structure and pasting of two types of HAMSs, Gelose 50 (HAMSI) and Gelose 80 (HAMSII), with apparent amylose content (AAC) of 45 % and 58 %, respectively, was studied using a multiscale approach including X-ray scattering, surface structures, particle size distribution, molecular size distributions and high temperature/pressure Rapid Visco Analysis (RVA)-4800 pasting. As compared to starch with no amylose (waxy maize starch, WMS) and 25 % amylose content (normal maize starch, NMS), HAMSI underwent similar structural and pasting changes as WMS and NMS upon microwave treatment, and it might primarily be attributed to the amylopectin fraction that was affected by cleavage of the connector chains between double helices and backbone chains, which decreased the crystallinity and thickness of the crystalline lamellae. However, the multi-scale structure of HAMSII was almost unaffected by this treatment. The pasting properties of fully gelatinized HAMSI starch showed a decrease in RVA-4800 peak and final viscosities after microwave treatment. In contrast, for HAMSII starch, the microwave treatment led to an increase in these viscosities. The combined results highlight the influence of varying AAC on the effects of microwave-mediated modification, leading to diverse alterations in the structure and functionality of starches.

Study on physicochemical characteristics of local colored rice varieties (black, red, brown, and white) fermented with lactic acid bacteria (SBM.4A)

In this study, the physicochemical properties of local colored rice flour were studied after modification through fermentation with lactic acid bacteria (LAB) SBM.4A. SBM.4A was LAB isolated from the rice washing water and was in the cladogram of the Pediococcus pentosaceus strain SRCM102739 CP028266.1 and Pediococcus pentosaceus strain SRCM102738 CP028264.1. The studied rice varieties were wakacinda (white rice), wakawondu (red rice), warumbia (brown rice), and wakaombe (black rice). Characterizations of both fermented and native rice flour included chemical composition, FTIR profile, crystallinity, morphology, and pasting properties. Fermentation did not introduce new chemical functional groups to the flour and only slightly increased crystallinity from approximately 22.5% to 25.05%. In contrast, fermentation greatly affected the chemical composition and pasting properties of rice flour. Protein content of the fermented flour increased up to 214% relative to the native rice flour. Effect of fermentation on pasting properties varied between rice varieties. Increase in peak and final viscosities was observed in red, brown, and black rice. The opposite effect was found in white rice. However, fermentation improved the stability of flour to retrogradation for all rice varieties. These showed that the fermentation improved the properties of the local-colored rice flour and may widen their application as food ingredients.

Internal Quality Assessment of East African Highland Cooking Banana (Musa spp.) Flour: Significance for Breeding and Industrial Applications

This study assessed the internal quality traits of East African Highland cooking banana flours, exploring their significance for breeding and potential industrial applications. Twenty cultivars (nine hybrids and eleven landraces) were used. Swelling power capacity, water solubility, water absorption capacity, water absorption index, freeze-thawing stability, and pasting characteristics of banana flour were assessed using standard methods. The results showed that cultivars with high swelling power also exhibited a high water absorption capacity and water absorption index, thus making them suitable for bakery industries. The water absorption capacity ranged between 5.66% (N2) and 11.68% (N11). Landraces KBZ (9.01) and NKYK (8.05), and hybrids N11 (11.68) and N9 (8.48) are suitable as thickeners due to high WAC. Hybrids (N7, 27.83%, and N9, 22.59%) and landraces (NMZ, 32.69%, and NFK, 34.24%) had low freeze-thawing stability, hence it is applicable as a food stabilizer. Landrace NKT (19.14%) and hybrid N9 (16.95%) had the highest solubility, and landrace KBZ (6.93%) and hybrid N3 (6.66%) had the lowest solubility. Landraces MSK (6265), NKY (3980), and NFK (3957), and hybrids N6 (3608), N7 (3505), and N9 (3281 RVU) had high peak viscosity. The trough viscosity, final viscosity, and breakdown viscosity of cultivars varied from 422.5 to 5004 RVU. The landraces MSK (5021 RVU) and NFK (4111 RVU) had the highest final viscosity, making them suitable for application in the food industry for thick and stable sauces. Landrace TRZ had the lowest pasting temperature (62.7 °C), making it advantageous for use where fast gelatinization is required, hence saving energy costs and cooking time. These findings suggest that the genetic attributes inherent in cultivars can be incorporated into breeding programs targeting required traits for industrial application.

Effects of Tremella fuciformis Mushroom Polysaccharides on Structure, Pasting, and Thermal Properties of Chinese Chestnuts (Castanea henryi) Starch Granules under Different Freeze-Thaw Cycles

The purpose of this study was to investigate the effect of Tremella fuciformis polysaccharides on the physicochemical properties of freeze-thawed cone chestnut starch. Various aspects, including water content, crystallinity, particle size, gelatinization, retrogradation, thermal properties, rheological properties, and texture, were examined. The results revealed that moderate freezing and thawing processes increased the retrogradation of starch; particle size, viscosity, shear type, hinning degree, and hardness decreased. After adding Tremella fuciformis polysaccharide, the particle size, relative crystallinity, and gelatinization temperature decreased, which showed solid characteristics. Consequently, the inclusion of Tremella fuciformis polysaccharide effectively countered dehydration caused by freezing and thawing, reduced viscosity, and prevented the retrogradation of frozen-thawed chestnut starch. Moreover, Tremella fuciformis polysaccharide played a significant role in enhancing the stability of the frozen-thawed chestnut starch. These findings highlight the potential benefits of incorporating Tremella fuciformis polysaccharides in starch-based products subjected to freeze-thaw cycles.