Effects of repeated and continuous dry heat treatments on the physicochemical and structural properties of quinoa starch

Enhancing Kodo millet starch-based hybrid gel for fat replacement in cookies: Dual modification (heat treatment-octenyl succinic anhydride) for improved properties

In this study, Kodo millet starch was modified using dry heat treatment and heat-moisture treatment, followed by esterification with 3 % octenyl succinic anhydride to enhance its functional and structural properties for hybrid gel formulation and application as a fat replacer in cookies. Heat treatment before esterification significantly increased the degree of substitution (0.0068 to 0.0109) and particle size (9.22 to 10.43 μm). Morphological analysis revealed irregularities and aggregation, while X-ray diffraction indicated reduced crystallinity. The modified starches exhibited non-Newtonian, shear-thinning behavior with stronger gel elasticity. The dual-modified starch in hybrid gel formulations exhibited effective stabilization over 30 days, with improved emulsification properties. When used in reduced-fat cookies, they maintained acceptable texture and appealing color at both 50 % and 100 % shortening replacement levels. The organoleptic analysis confirmed that cookies with 100 % shortening replacement had increased overall acceptability, indicating the potential of dual-modified starch hybrid gels as effective fat replacers.

Physical Modification of Starch in Plant-Based Flours: Structural, Physicochemical, and Pasting Property Changes and Potential Applications in Baked and Extruded Products

Unmodified starches and flours have physicochemical and functional limitations that include low solubility, limited swelling power, low water absorption, and a high tendency to retrogradation and syneresis-characteristics that restrict their use in the agri-food industry. To overcome these limitations, several physical modifications have been proposed, such as hydrothermal treatments (heat-moisture treatment, HMT; dry-heat treatment, DHT; and annealing, ANN), as well as extrusion and the use of microwaves. HMT, DHT, and ANN are processes that are performed at low, intermediate, and high-moisture content, respectively. Extrusion employs high temperatures, pressure, and shear forces, whereas microwaves use photon irradiation and dielectric heating. This review focuses on the importance of physical modifications of flours and their effect on the physicochemical, structural, and rheological properties of starch. Flours subjected to these treatments show improvements in their physicochemical characteristics, including a higher content of slow-digestion starch and resistant starch fractions. When applied in the production of baked and extruded products, they enhance texture and extend shelf life, while maintaining acceptable sensory qualities. In addition, these processes increase the versatility of flours from non-conventional sources, such as gluten-free cereals, legumes, roots, and tubers, expanding their possibilities of use in the agri-food industry.

Effects of Lactobacillus plantarum fermentation on the structure and digestion of resistant starch type 3 and properties of fermented starch in the simulated digestion system

The information about the properties of resistant starches after microbial fermentation is scarce. This study explores the relationship between the structure and digestibility of resistant starch type 3 (RS3, retrograded or recrystallized starch) following Lactobacillus plantarum fermentation. Additionally, in vitro simulations are conducted on fermented samples with and without Lactobacillus plantarum. The fermentation process was categorized into the early (before 4 h), middle (4-12 h), and late (12-16 h) stages. The A (Degree of polymerization (DP) 6-12), B1 (DP 13-24), and B2 (DP 25-36) chains in the early stage, B1 and B3 chains (DP ≥ 37) in the middle stage, and B3 chain in the late stage degraded sequentially. Interestingly, early fermentation did not hydrolyze the rapidly digestible starch but hydrolyzed the slowly digestible starch that constitutes the periphery of the RS3. Besides, the double helix hydrogen bond was weakened in the early and late fermentation, while the inter-strand hydrogen bond was enhanced in the middle fermentation. These structure changes significantly affect the digestibility. Simultaneously, Lactobacillus plantarum protected the fermented 8-hour sample from morphology and crystal structure damage to the gastric acid. Therefore, optimizing fermentation duration decreases digestibility, and introducing Lactobacillus plantarum within gastrointestinal systems protects against gastric acid damage of RS3.

Superheated steam processing as a novel strategy for rapid synthesis of millet-starch citrates: Preparation, characterization, and in vitro starch digestibility

This study investigates the potential of superheated steam (SS) as a rapid and sustainable method for synthesising millet starch citrates with improved physicochemical and functional properties. Millet starch was esterified with citric acid (CA) under varying SS conditions (160-180 °C, 15-45 min) to optimise the degree of substitution (DS) and evaluate its influence on starch functionality. A range of DS values (0.023 to 0.121) were achieved, with the highest DS observed at 170 °C for 45 min. Structural analysis using Fourier-transform infrared spectroscopy confirmed successful esterification, with the appearance of a new peak at 1735 cm-1 indicating ester bond formation. X-ray diffraction showed a reduction in crystallinity with increasing DS, while polarised light microscopy and confocal scanning laser microscopy revealed alterations in molecular organisation. Scanning electron microscopy demonstrated minimal disruption to granule morphology. Contact angle measurements indicated increased hydrophobicity, with water contact angles rising from 29.63° in native starch to 71.63° in high DS samples. Additionally, a significant (p < 0.05) reduction in amylose content and paste viscosities was observed, correlating with improved resistance to gelatinisation and retrogradation. In vitro digestibility analysis showed a substantial increase in resistant starch content, from 18.69 % in native starch to 40.11 % in high DS samples. These findings highlight SS as an efficient and eco-friendly technology for producing starch citrates with tailored functionalities, particularly suited for low-glycaemic response and health-promoting food applications.

Impact of repeated freeze-thawing on the functional, molecular, rheological and thermal properties of isolated quinoa (Chenopodium quinoa Willd.) starch

This study was undertaken to understand the functionality of quinoa starch (QS) in frozen foods. The effects of different cycles of freeze-thaw treatment (0, 2, 4, 6, and 8 cycles) on the functional, molecular, rheological, and thermal characteristics of starch from quinoa seeds were investigated. The extraction yield of QS was 52 %, with a purity value of 97.98 %. The study observed amorphization of starch molecule after repeated FT, as it primarily affected the crystalline domains. Reduction in the oil absorption capacity (OAC) of starch from 115 % to 95 % was linked to increase in surface roughness, which was further corroborated by scanning electron microscopy and contact angle analysis. Further studies also revealed reduction in relative crystallinity from 36.21 % to 32.34 %, degree of ordered structure from 1.59 to 1.06, and gelatinization enthalpy from 19.99 J/g to 8.48 J/g, as indicated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and differential scanning calorimetry (DSC), respectively. All starch gels showed a pseudo-plastic behaviour (η < 1), which the power law model described well. Additionally, the gel-forming ability of starches improved as indicated by higher values of storage (G') and loss (G″) moduli. In conclusion, the number of freeze-thaw cycles significantly influences the various characteristics of QS.

The mechanisms of thermal processing techniques on modifying structural, functional and flour-processing properties of whole-grain highland barley

The mechanisms underlying three thermal processing methods, namely hot-air drying, microwave irradiation, and heat fluidization, were systematically investigated to evaluate their effects on the structural, functional, and flour-processing properties of whole-grain highland barley. Starch granules were partially damaged when treated with hot-air drying and microwave irradiation. However, these granules were predominantly aggregated or encapsulated in proteins following heat fluidization. Accordingly, flour produced through heat fluidization exhibited the lowest relative crystallinity of 3.43 % and the greatest α → β shifts in secondary protein structures, compared to other treatments. These structural changes led to improved water/oil holding capacity, enhanced elastic property, reduced enthalpy of 4430 J/kg and breakdown viscosity of 0.24 Pa·s. Moreover, fresh noodles made from heat fluidization-treated highland barley exhibited superior textural features. Overall, heat fluidization could be a more effective method to modify the flour-processing properties of whole highland barley flour and enhance its applicability in the food industry.

Influence of the Nutritional Composition of Quinoa (Chenopodium quinoa Willd.) on the Sensory Quality of Cooked Quinoa

In order to explore the effect of the content of nutritional components of quinoa on its sensory quality, 22 quinoa varieties were collected from 11 major quinoa-producing areas at home and abroad as experimental materials. The contents of total starch, protein, fat, crude fiber, ash, VB1, VB2, moisture and saponin were determined, and the sensory evaluation and electronic tongue analysis of cooked quinoa were carried out. The sensory quality of quinoa was comprehensively evaluated by correlation analysis, principal component analysis and cluster analysis. The results show that the contents of various nutritional components had significant effects on the sensory quality of quinoa (p < 0.05). Quinoa with high starch, high VB1, moderate fat, moderate moisture, low protein, low crude fiber, low ash and low saponin content had better cooking quality and was more popular. Electronic tongue analysis showed that the sweet response value of cooked quinoa was the highest, followed by the bitter response value. No. 12 and No. 9 cooked quinoa samples had the best comprehensive taste, the highest sensory score and the best cooking quality. This study preliminarily clarified the relationship between the content of different nutritional components in quinoa and its sensory quality, which could provide reference for the selection of raw materials and breeding of quinoa varieties for different processing purposes.

Multi-Scale Structures, Functional Properties, and Applications of Starch Modified by Dry Heat Treatment

Dry heat treatment (DHT) is considered a green technology to modify starch structure and functionality since it does not generate effluents and avoids the use of chemical compounds, however, there is still no comprehensive understanding of the effects and mechanisms on the multi-scale structure and their relationship with functionality. This paper reviewed and analyzed the effects of DHT on multi-scale starch structures and functional properties, compared the performance of continuous and repeated DHT, discussed a mechanism of starch dry heating, and summarized the applications of dry-heated starches. DHT evaporates water, accelerates the movement of starch molecules, and breaks hydrogen bonds, which changes the multi-scale structure. In turn, structural modifications promoted by DHT affect the hydration properties, thermal stability, slowly digestible/resistant starch formation, and glycemic index. The multi-scale structure and functional changes after DHT are strongly affected by the starch botanical source and process conditions. This review contributes to understanding the starch DHT modification and establishes a theoretical basis for advancing DHT applications in the starch industry.

New insights into influencing the extraction efficiency of tigernut oil: Impact of heat on oil absorption and enzymatic hydrolysis of tigernut starch in a starch-protein-oil model system

Tigernut is a potential source of valuable edible oil; however, current oil extraction techniques are inefficient. We assessed high temperature-induced variations in oil absorption and enzymatic hydrolysis of tigernut starch (TS) in the presence of protein to explore the intrinsic reasons for the low oil extraction from tigernut. The results showed that, due to high temperature and the presence of protein, an increase in the volume mean diameters and agglomeration of TS granules occurred. As the temperature increased (80-140 °C), the relative crystallinity (19.09 %-24.40 %) of the long-range ordered structure and the orderliness of the short-range ordered structure increased, the total oil absorption (TOA: 0.25-0.19 g oil/g sample) decreased, and the starch-lipid complex index (2.56 %-24.61 %) increased. With increasing temperature in the range of 170-200 °C, the short-range ordered structure of TS became more compact, and the TOA (0.18-0.14 g oil/g sample) and the starch-lipid complex index (24.61 %-5.64 %) decreased. Changes in the structure of TS led to an increase and then a decrease in its thermal stability, an enhancement of the gel network structure, and a weakening of enzymatic hydrolysis. Results can help reveal the oil absorption mechanism of TS and regulate its physicochemical properties for the efficient extraction of tigernut oil.

Structural and physicochemical properties of pea starch dual-treated with dry heating and galactomannans

The research on the combination of starch and galactomannans (GM) with dry heat treatment (DHT) is currently insufficient, which hinders the starch application. In this study, the impacts of dry heat treatment and GM complex on the structural, gelatinization properties, and digestibility of pea starch (PS) were investigated. The gelatinization viscosity and gel hardness of dry heated-PS were decreased. Moreover, the relative crystallinity of PS was improved when individually treated by dry heating and GM complex, resulting in the decline of digestibility. Besides, the long molecular chains (DP ≥ 37) proportion and the semi-crystalline lamellae thickness of the PS-GM-DHT complex were increased, which was relevant to the ratio of galactose/mannose residues in galactomannan. In particular, PS was more prone to complex with locust bean gum following dry heat treatment, which has the highest mannose ratio. The present study provided the fundamental information to promote the starch application further.

An overview on the dry heat treatment (DHT) for starch modification: Current progress and prospective applications

Starch plays a pivotal role in numerous applications, making the enhancement of its functionality through physical processes increasingly important. Dry heat treatment (DHT) is a straightforward and eco-friendly technique that significantly improves starch characteristics and boosts food quality. This method has emerged as a focal point in starch modification research in recent years. This paper reviews current studies on the DHT of starches from various botanical sources, presenting key concepts and methodologies while delving into the impacts and mechanisms of DHT on the structural and physicochemical properties of starches. Furthermore, it elaborates on how additional components, such as ionic gums, amino acids, and sugars, can enhance the functionality of starches modified by DHT. Additionally, this review discusses the practical applications of dry heat-modified starches in the food industry, aiming to offer valuable insights for ongoing research and potential applications in enhancing food quality and functionality through innovative starch modifications.

Physicochemical properties and in vitro digestion of quinoa starch induced by combination of ultrasound and konjac glucomannan

This study investigated the effects of konjac glucomannan (KGM) and ultrasound on the solubility, pasting properties, rheological behavior, thermal properties, structural characteristics, and digestibility of quinoa starch. The results demonstrated significant improvements in starch properties with both ultrasound and KGM treatment, with the most pronounced effects observed in the combined ultrasound and KGM treatment. This combined treatment led to enhanced energy storage modulus and loss modulus, indicating improved rheological properties. Additionally, combined treatment improved solubility, thermal stability, and digestibility and resulted in a more ordered structure and increased paste enthalpy compared with ultrasound or KGM treatment. Scanning electron microscopy and particle size analysis revealed a more compact starch structure following the synergistic treatment. X-ray diffraction and Fourier transform infrared spectroscopy showed a more organized, complex structure. These findings offer valuable insights into the application of ultrasound and KGM to enhance the performance and quality of quinoa starch.

How does high hydrostatic pressure treatment improve the esterification of quinoa (Chenopodium quinoa Willd.) starch?

High hydrostatic pressure (HHP) treatment was combined with octenyl succinic anhydride (OSA) modification of quinoa starch (QS) to improve esterification efficiency. The modified QS was used as a stabilizer to prepare a Pickering emulsion. The results showed that the HHP treatment disrupted the morphology and crystalline structure of QS, exposed numerous hydrophilic hydroxyl groups, and added esterification reaction sites. The degree of substitution (DS) and esterification efficiency (RE) of OSA-HHP-QS were significantly (p < 0.05) increased compared with OSA-QS. In addition, the short-range ordering, relative crystallinity, and thermal stability of OSA-HHP-QS decreased with increasing treatment pressure. Except for OSA-HHP200-QS, the starch granules treated at 200 MPa were annealed, resulting in molecular recrystallization. The Contact angle, emulsion stability index (ESI), and emulsion activity index (EAI) indicated that the emulsions stabilized with OSA-HHP-QS were highly stable. Therefore, HHP can be used as a novel technology to assist OSA modified starches in stabilizing Pickering emulsions.

Recent Advances on Starch-Based Adsorbents for Heavy Metal and Emerging Pollutant Remediation

Starch is one of the most abundant polysaccharides in nature and has a high potential for application in several fields, including effluent treatment as an adsorbent. Starch has a unique structure, with zones of different crystallinity and a glycosidic structure containing hydroxyl groups. This configuration allows a wide range of interactions with pollutants of different degrees of hydrophilicity, which includes from hydrogen bonding to hydrophobic interactions. This review article aims to survey the use of starch in the synthesis of diverse adsorbents, in forms from nanoparticles to blends, and evaluates their performance in terms of amount of pollutant adsorbed and removal efficiency. A critical analysis of the materials developed, and the results obtained is also presented. Finally, the review provides an outlook on how this polysaccharide can be used more effectively and efficiently in remediation efforts in the near future.

Effects of different heat treatment methods on physicochemical characteristics and in vitro digestibility of sweet potato flour and its application in meal replacement flour

This study examined the effects of various heat treatments on physicochemical properties, functionality, and starch digestibility of sweet potato flour. Heat treatments darkened the color but did not change the chemical structure. Solubility decreased and swelling power increased (17.3%-18.3%) with baking, frying, and microwaving, while extrusion and steaming had opposite effects. Rapidly digestible starch content increased (8.96%-41.91%) in all treatments except steaming, which reduced slowly digestible starch (61.81%-28.97%). Based on the analysis of these studies, using low-temperature baked and extruded sweet potato flour as the main raw material, combined with the concept of complete nutrition, supplemented by nutritious ingredients such as quinoa, oats, and whey protein, we have successfully developed two sweet potato meal replacement flours (SP-1 and SP-2) and found they had good brewing properties and showed shear-thinning behavior. This study provided theoretical basis for sweet potato deep processing and functional product development. PRACTICAL APPLICATION: This paper studied the effects of different heat treatments on sweet potato flour, and developed two meal replacement flour based on this, to provide a theoretical basis for the application of the sweet potato industry.

Effect of maturity on the drying characteristics of lotus seed and molecular structure, gelation and digestive properties of its starch

Maturity and drying treatment are important factors affecting the processing characteristics of lotus seeds and its starch. This study aimed to investigate the effect of maturity (from low to high-M-1, M-2, M-3, M-4) on far-infrared drying kinetics of lotus seeds, and on the variation of structure, gelation and digestive properties of lotus seed starch (LSS) before and after drying. As the maturity increased, the drying time reduced from 5.8 to 1.0 h. The reduction of drying time was correlated with the decrease of initial moisture content, the increase of water freedom and the destruction of tissue structure during ripening. The increased maturity and drying process altered the multiscale structure of LSS, including an increase in amylose content, disruption of the short-range structure, and a decrease in relative crystallinity and molecular weight. The viscosity, pasting temperature and enthalpy of LSS decreased during ripening, and drying treatment caused the further decrease. The digestibility of LSS increased during ripening and drying. Lotus seeds at M-4 would be optimal for obtaining shorter drying time, lower pasting temperature and enthalpy, and higher digestibility. This study provided theoretical guidance for achieving effective drying process and screening LSS with suitable processing properties through maturity sorting.

Cutting-edge progress in green technologies for resistant starch type 3 and type 5 preparation: An updated review

Resistant starch (RS) is a dietary fiber that resists starch hydrolysis in the small intestine, and is fermented in the colon by microorganisms. RS not only has a broad range of benefits in the food and non-food industries but also has a significance impact on health promotion and prevention of non-communicable diseases. RS types 3 and 5 have been the focus of research from an environment-friendly perspective. RS3 is normally formed by recrystallization after physical modification, whereas RS5 is obtained by the complexation of starch and fatty acids through the thermomechanical methods. This review provides updates and approaches to RS3 and RS5 preparations that promote RS content based on green technologies. This information will be useful for future research on RS development and for identifying preparation methods for functional food.

Optimisation of dry heat treatment conditions for modification of faba bean (Vicia faba L.) starch

Faba bean is a protein-rich starchy grain that is underutilised in the UK. The starch of faba bean can be modified using environmentally friendly methods like dry heat treatment (DHT) to enhance functional and its physicochemical properties. This study investigated the impact of dry heat temperature and time on the structure, functional and physicochemical properties of faba bean starch (FBS) using a two-factor central composite rotatable design. Factors (DHT temperature:100-150 °C and DHT time:0.5-5 h) with their respective α mid-point values led to 13 experimental runs. Selected pasting and functional properties were measured as response variables. Corn starch was included as a reference and compared with the FBS modified using the optimized conditions. DHT increased peak (approx. 2205-2267 cP), final (approx. 3525-3642 cP) and setback (approx. 1887-1993 cP) viscosities but decreased the amylose content of FBS. Colour, as measured by lightness value, morphology and crystalline type were not altered but the starches showed a loss of order and an increase in crystallinity after DHT. FBS appeared resilient to DHT but showed higher swelling power and pasting properties compared to the corn starch control. The optimum DHT conditions to produce starch with desirable properties are a temperature of 100 °C for 0.1716 h, with a desirability factor of 66 %.

Strategic exploration of whole grain cereals in modulating the glycaemic response

In the current context, diabetes presents itself as a widespread and complex global health issue. This study explores the significant influence of food microstructure and food matrix components interaction (protein, lipid, polyphenols, etc.) on the starch digestibility and the glycaemic response of post-prandial glycemia, focusing on the potential effectiveness of incorporating bioactive components from whole grain cereals into dietary strategies for the management and potential prevention of diabetes. This study aims to integrate the regulation of postprandial glycaemic homeostasis, including the complexities of starch digestion, the significant potential of bioactive whole grain components and the impact of food processing, to develop a comprehensive framework that combines these elements into a strategic approach to diabetes nutrition. The convergence of these nutritional strategies is analyzed in the context of various prevalent dietary patterns, with the objective of creating an accessible approach to mitigate and prevent diabetes. The objective remains to coalesce these nutritional paradigms into a coherent strategy that not only addresses the current public health crisis but also threads a preventative approach to mitigate future prevalence and impact.

Effects of repeated and continuous dry heat treatments on the physicochemical, structural, and in vitro digestion properties of chickpea starch

The study investigated the impacts of repeated (RDH) and continuous dry heat (CDH) treatments on the physicochemical, structural, and in vitro digestion properties of chickpea starch. The results of SEM and CLSM showed that more fissures and holes appeared on the surface of granules as the treated time of CDH and the circles of RDH increased, both of which made the starch sample much easier to break down by digestive enzymes. Moreover, the fissures and holes of starch granules treated by CDH were more obvious than those of RDH. The XRD and FT-IR results suggested that the crystal type remained C-type, and the relative crystallinity and R1047/1022 of the chickpea starch decreased after dry heat treatments. In addition, a marked decline in the pasting viscosity and gelatinization temperature of chickpea starches was found with dry heat treatments. Moreover, the increased enzyme accessibility of starch was fitted as suggested by the increased RDS content and digestion rate. This study provided basic data for the rational design of chickpea starch-based foods with nutritional functions.

Effects of hydrocolloids on mechanical properties, viscoelastic and microstructural properties of starch-based modeling clay

The effects of various hydrocolloids (guar gum, xanthan gum, and carboxymethyl cellulose) on the texture, rheology, and microstructural properties of modeling clay prepared with cassava starch were investigated. Notably, incorporation of 3 % guar gum and 4 % xanthan gum into starch-based modeling clay resulted in enhancements of 94.12 % and 77.47 % in cohesiveness, and 64.70 % and 66.20 % in extensibility, respectively. For starch-based modeling clay with added guar gum and xanthan gum, compared to formulations without hydrocolloids, the linear viscoelastic range exceeded 0.04 %, and the frequency dependence of both maximum creep compliance (Jmax) and storage modulus (G') was significantly reduced. This indicates a more stable network structure and enhanced resistance to deformation. Results from Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed that the physical interactions between starch and various hydrocolloids, along with the addition of these hydrocolloids, inhibited the degradation effect of thermomechanical processing on the crystalline structure of starch. With the addition of guar gum, it is observed that a continuous and dense network structure forms within the starch-based modeling clay, and starch particles are distributed uniformly. In conclusion, hydrocolloids enhances the properties of starch-based modeling clay, introducing an innovative solution to the modeling clay sector.

Advancements in enhancing resistant starch type 3 (RS3) content in starchy food and its impact on gut microbiota: A review

Resistant starch type 3 (RS3), often found in cooked starchy food, has various health benefits due to its indigestible properties and physiological functions such as promoting the abundance of gut beneficial microbial flora and inhibiting the growth of intestinal pathogenic bacteria. However, it is challenging to develop starchy food with high RS3 content. This review aims to provide a detailed overview of current advancements to enhance RS3 content in starchy food and its effects of RS3 on gut microbiota. These approaches include breeding high-amylose cereals through gene editing techniques, processing, enzyme treatments, storage, formation of RS3 nanoparticles, and the incorporation of bioactive compounds. The mechanisms, specific conditions, advantages, and disadvantages associated with each approach and the potential effects of RS3 prepared by different methods on gut microbiota are summarized. In conclusion, this review contains important information that aims to provide guidelines for developing an efficient RS3 preparation process and promote the consumption of RS3-enriched starchy foods to improve overall health outcomes.

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.

Structure and functional properties of taro starch modified by dry heat treatment

Taro starch (TS) was modified by dry heat treatment (DHT) for different periods (1, 3, 5, and 7 h at 130 °C) and temperatures (90, 110, 130, and 150 °C for 5 h) to expand its applications in food and other industries. The structure and functional properties of DHT-modified TS were characterized. It was found that TS granules became agglomerated after DHT, and the particle size, amylose content, solubility, and retrogradation enthalpy change of TS increased with increasing dry heating time and temperature, whereas the relative crystallinity, molecular weight, swelling power, gelatinization temperature, and enthalpy change decreased. The absorbance ratio of 1047 cm-1/1022 cm-1 for DHT-modified TS (except at 7 h) was higher than that of native TS. DHT increased the contact angle of TS in a time- and temperature-dependent manner. At a moderate strength, DHT increased the pasting viscosity, relative setback value, and storage modulus but decreased the relative breakdown value. Moreover, DHT (except at 150 °C) caused a decrease in the rapid digestive starch content and estimated glycemic index of TS. These results suggested that DHT-modified TS could be used in foods with high viscosity requirements, gel foods, and low-glycemic index starch-based foods.

Structural, physicochemical properties and noodle-making potential of quinoa starch and type 3, type 4, and type 5 quinoa resistant starch

This study prepared type 3, type 4, and type 5 quinoa resistant starch (QRS3, QRS4, and QRS5) from quinoa starch (QS), compared their structural and physicochemical properties and evaluated their noodle-making potential. The results showed that the molecular weight of QRS3 decreased, the number of short-chain molecules increased, and its crystal type changed to B-type after gelatinization, enzymatic hydrolysis, and retrogradation. QRS4 is a phosphorylated cross-linked starch, with a surface morphology, particle size range, and crystal type similar to QS, but displaying modified thermodynamic properties. QRS5 is a complex of amylose and palmitic acid. It displays typical V-type crystals, mainly composed of long chain molecules and primarily exhibits a block morphology. The noodles prepared by replacing 20 % wheat flour with QS, QRS3 and QRS5 have higher hardness and are suitable for people who like elasticity and chewiness. QRS4 noodles are softer and suitable for people like elderly and infants who prefer soft foods. In conclusion, significant differences were evident between the fine structures, crystal types, physicochemical properties and potential applications of QS and the three QRSs. The results may expand the application of QS and QRS in the food and pharmaceutical industries.

Effect of Starch on the Solubility of Quinoa Protein Isolates during Heat Treatment

There is increasing interest in developing quinoa products due to their unique nutritional value. Starch and protein are the primary components in quinoa, and the interaction between them affects the quality of quinoa products. This study extracted the starch and protein from quinoa and simulated the thermal processing of quinoa to investigate the effects of starch on the solubility and structure of quinoa protein isolates during heat treatment. The structure of quinoa protein isolates was characterized by fluorescence spectroscopy, Fourier transform infrared spectroscopy, laser particle size analysis, and scanning electron microscopy. The results showed that starch decreased protein solubility, and the maximum solubility was obtained after heating for 5 min. After starch addition during heat treatment, the surface charge distribution of protein changed, the degree of protein aggregation increased, the particle size of proteins increased, the thermal stability increased, and the β-sheet ratio of the proteins increased, suggesting that the protein structure is more ordered, which is the structural foundation of protein solubility decreasing. The research about the interaction between starch and protein and the effects on the solubility of protein could provide a reference for quinoa products processing.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

Impact of pH on physicochemical properties of corn starch by dry heat treatment

This study investigated the effects of temperature, pH, and starch genotype on starch characteristics after dry heat treatment (DHT). DHT starches were prepared according to 19 DHT conditions, constructed using a D-optimal design, and analyzed with respect to apparent amylose (AAM) content, X-ray diffraction (XRD) pattern, relative crystallinity (RC), solubility and swelling power (SP), thermal properties, and pasting viscosity. The DHT starches maintained their granular structures even after DHT at pH 3, although there was some damage to their granular surfaces. The DHT starches showed lower amylose content, RC, SP, gelatinization temperature and enthalpy, degree of retrogradation, and pasting viscosity, but higher solubility, compared to those of native starches. These DHT effects were more pronounced as pH decreased at each temperature, regardless of the starch genotype. Overall, DHT can be used to expand the physical functionality of high-amylose and highly crystallized starches with poor properties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01353-7.

Effects of semidry milling on the properties of highland barley flour and the quality of highland barley bread

BACKGROUND

This study aimed to investigate the effects of semidry milling on the quality attributes of highland barley flour and highland barley bread. Highland barley flours were prepared by dry (DBF), semidry (SBF), and wet (WBF) milling methods. The properties of different highland barley flours were analyzed, and highland barley breads made from different highland barley flours were evaluated.

RESULTS

The results showed that WBF had the lowest damaged starch content (15.2 g kg^-1 ), and the contents of damaged starch in SBF-35 and SBF-40 (43.5 g kg^-1 and 24.1 g kg^-1 respectively) were lower than that of DBF (87.6 g kg^-1 ). And SBF-35 and SBF-40 with large particles exhibited low hydration performance. In addition, SBF-35 and SBF-40 had higher pasting viscosity, pasting temperature, ΔH, and relative crystallinity, consequently resulting in better gel properties than other highland barley flours. These properties could help SBF-35 and SBF-40 develop high-quality bread with large specific volume and superior crumb structure and texture that is similar to the bread with WBF.

CONCLUSION

Overall, semidry milling not only could improve the characteristics of HBF, but also avoid high starch damage by dry milling and water wasting by wet milling. What is more, highland barley breads with SBF-35 and SBF-40 had preferable appearance and crumb texture. Therefore, semidry milling could be regarded as a feasible way to produce highland barley flour. © 2023 Society of Chemical Industry.

Native and modified starches from underutilized seeds: Characteristics, functional properties and potential applications

Seeds represent a potential source of starch, containing at least 60-70% of total starch, however many of them are treated as waste and are usually discarded. The review aim was to analyze the characteristics, functional properties, and potential applications of native and modified starches from underutilized seeds such as Sorghum bicolor L. Moench (WSS), Chenopodium quinoa, Wild. (QSS), Mangifera indica L. (MSS), Persea americana Mill. (ASS), Pouteria campechiana (Kunth) Baehni (PCSS), and Brosimum alicastrum Sw. (RSS). A systematic review of scientific literature was carried out from 2014 to date. Starch from seeds had yields above 30%. ASS had the higher amylose content and ASS and RSS showed the highest values in water absorption capacity and swelling power, contrary to MSS and PCSS while higher thermal resistance, paste stability, and a lower tendency to retrograde were observed in MSS and RSS. Functional properties such as water solubility, swelling power, thermal stability, low retrogradation tendency, and emulsion stability were increased in RSS, WSS, QSS, and MSS with chemical modifications (Oxidation, Oxidation-Crosslinking, OSA, DDSA, and NSA) and physical methods (HMT and dry-heat). Digestibility in vitro showed that WSS and QSS presented high SDS fraction, while ASS, MSS, PCSS, and HMT-QSS presented the highest RS content. Native or modified underutilized seed starches represent an alternative and sustainable source of non-conventional starch with potential applications in the food industry and for the development of healthy foods or for special nutritional requirements.

Toward a comprehensive understanding of various milling methods on the physicochemical properties of highland barley flours and eating quality of corresponding sugar-free cookies

Highland barley (HB) was subjected to dry-, semidry-, wet-milling methods and assessed for flour physicochemical properties and eating quality of corresponding sugar-free cookies. Results showed that there were significant differences between different milled flours in damaged starch content, particle size, hydration, pasting properties, and color. High a* values and poor hydration/pasting properties of wet-milled flours were associated with its smallest particle size and lowest content of damaged starch (25.3%), β-glucan (1.87%), and dietary fiber (10.87%), resulting in dark brown color, slightly high spread ratio, low hardness, and fast digestibility of the corresponding cookies. Conversely, the low digestibility of the cookies (predicted glycemic index 58.85) prepared from dry-milled flours was attributed to the higher content of dietary fiber, β-glucan and V-type starch-lipid complex, which would affect enzyme accessibility and may be beneficial for making HB sugar-free cookies. This study is expected to promote the development of HB functional foods.

Effects of egg powder on the structure of highland barley dough and the quality of highland barley bread

The influences of egg white (EW), egg yolk (EY) and whole egg (WE) on the structure of highland barley dough and the quality of highland barley bread were explored. The results showed that egg powder reduced G' and G" of highland barley dough, which led to the softer texture of dough and endowed bread with a larger specific volume. EW increased the percentage of β-sheet of highland barley dough, EY and WE promoted the transformation from random coil to β-sheet and α-helix. Meanwhile, more disulfide bonds were formed from free sulfhydryl groups in the doughs with EY and WE. These properties of highland barley dough could help highland barley bread develop a preferable appearance and textural feature. It is worth noting that highland barley bread containing EY has more flavorful substances and a better crumb structure, which were similar to that of whole wheat bread. The highland barley bread with EY received a high score according to the sensory evaluation in consumer acceptance.

Microwave Modification of Quinoa Grains at Constant and Varying Water Content Modulates Changes in Structural and Physico-Chemical Properties of the Resulting Flours

Microwave-assisted heat moisture treatment (MWT) was applied to quinoa grains, a nutritious gluten-free pseudocereal of great interest in food product development, to achieve the physical modification of the quinoa flour. The effect of treating quinoa grains at different initial water contents (WC; 10%, 20%, and 30%) in two operational systems was compared: one open at atmospheric pressure and variable WC (V system), and the other in hermetic containers at constant WC (C system). The morphological structure of the obtained flours and their techno-functional, rheological, and thermal properties were evaluated. MWT proved to be effective in modifying these properties, the main effects probably being caused by protein denaturation and aggregation, and intragranular molecular rearrangements of starch, with disruption of short-range molecular order and even the partial collapse of starch granules in the samples treated at the highest WC. The greatest differences were observed for the 20 and 30% WC treated-samples, particularly when using C system, which increased their water absorption capacity and decreased their foaming, emulsion, and gel-forming capacities. Based on these results, the control of WC and its evolution during MWT of quinoa grains appears to be a viable and effective approach to adapt flour functionality to the needs of food production, allowing a wider range of flour properties depending on the MWT conditions.

Structural, Physicochemical and Digestive Property Changes of Potato Starch after Continuous and Repeated Dry Heat Modification and Its Comparative Study

To investigate the effects of repeated dry heat treatment (RDH) and continuous dry heat treatment (CDH) on the structure and physicochemical and digestive properties of potato starch, potato starch was treated continuously and repeatedly at 130 °C for 3-18 h. The results showed that the crystalline form of starch was consistent with the original type B. Still, its physicochemical properties, such as swelling power, transparency, peak viscosity (PV), final viscosity (FV), breakdown (BD) and thermal properties (To, Tp, Tc, ΔT), tended to decrease. At the same time, solubility and RS increased after dry heat treatment. Moreover, RDH-treated starches were higher than CDH-treated ones in terms of molecular weight, crystallinity, swelling power, transparency and final viscosity for the same treatment time. Still, there was no significant difference between the thermal properties of the two. Meanwhile, the resistant starch (RS) content showed a downward trend after the peak value of 9 h of CDH treatment and five cycles of RDH treatment with increasing treatment time and the number of cycles, indicating a decrease in the overall digestibility of the starch. Overall, RDH had a more significant effect on potato starch's structure and physicochemical properties than CDH.

Thermal properties of different types of starch: A review

Starch is present in high amount in various cereals, fruits and roots & tubers which finds major application in industry. Commercially, starch is rarely consumed or processed in its native form, thus modification of starch is widely used method for increasing its application and process stability. Due to the high demand for starch in industrial applications, researchers were driven to hunt for new sources of starch, including modification of starch through green processing. Thermal properties are significant reference parameters for evaluating the quality of starch when it comes to cooking and processing. Modification of starches affects the thermal properties, which are widely studied using Differential scanning calorimeter or Thermogravimetric analysis. It could lead to a better understanding of starch's thermal properties including factors influencing and expand its commercial applications as a thickener, extender, fat replacer, etc. in more depth. Therefore, the review presents the classification of starches, factors influencing the thermal properties, measurement methods and thermal properties of starch in its native and modified form. Further, this review concludes that extensive research on the thermal properties of new sources of starch, as well as modified starch, is required to boost thermal stability and extend industrial applications.

Quinoa Snack Production at an Industrial Level: Effect of Extrusion and Baking on Digestibility, Bioactive, Rheological, and Physical Properties

This research aimed to produce gluten-free snacks on a pilot scale from quinoa flour. These snacks experienced an extrusion process, followed by baking. The effects of these technological processes on carbohydrate and protein digestibility, extractable phenolic compounds (EPP), hydrolyzable phenolic compounds (HPP), antioxidant capacity, and physical properties were evaluated in raw quinoa flour and extruded snacks. Extrusion increased digestible starch (RDS) from 7.33 g/100 g bs to 77.33 g /100 g bs. Resistant starch (RS) showed a variation of 2 g/100 g bs. It is noteworthy that protein digestibility increased up to 94.58 g/100 bs after extrusion and baking. These processes increased HPP content, while EPP and carotenoid content decreased. The samples showed significant differences (p < 0.05) in the antioxidant properties determined through the DPPH and ABTS methods. Values of 19.72 ± 0.81 µmol T/g were observed in snacks and 13.16 ± 0.2 µmol T/g in raw flour, but a reduction of up to 16.10 ± 0.68 µmol T/g was observed during baking. The baking process reduced the work of crispness (Wcr) from 0.79 to 0.23 N.mm, while the saturation (C*) was higher in baked ones, showing higher color intensity. The baking process did not influence the viscosity profile. The results in this study respond to the growing interest of the food industry to satisfy consumer demand for new, healthy, and expanded gluten-free snacks with bioactive compounds.

Advances in isolation, characterization, modification, and application of Chenopodium starch: A comprehensive review

The Chenopodium genus includes >250 species, among which only quinoa, pigweed, djulis, and kaniwa have been explored for starches. Chenopodium is a non-conventional and rich source of starch, which has been found effective in producing different classes of food. Chenopodium starches are characterized by their smaller granule size (0.4-3.5 μm), higher swelling index, shorter/lower gelatinization regions/temperature, good emulsifying properties, and high digestibility, making them suitable for food applications. However, most of the investigations into Chenopodium starches are in the primary stages (isolation, modification, and characterization), except for quinoa. This review comprehensively explores the major developments in Chenopodium starch research, emphasizing isolation, structural composition, functionality, hydrolysis, modification, and application. A critical analysis of the trends, limitations, and scope of these starches for novel food applications has also been provided to promote further scientific advancement in the field.

Appropriate microwave improved the texture properties of quinoa due to starch gelatinization from the destructed cyptomere structure

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Microwave dispersed quinoa starch aggregates into independent granules.

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Dispersed starch granules were hydrated and gelatinized to form network structure.

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Microwave maintained the crystal form while changed the crystallinity.

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Excessive microwave makes the starch partially gelatinize and formed blocks.

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Moderate microwave treatment can improve the hardness and stickiness of quinoa.

Texture characteristics of quinoa under microwave (MW) irradiation were studied from the perspective of starch gelatinization. MW reduced the light transmittance and increased the hardness and stickiness of quinoa. Microstructure showed that MW dispersed the vesicular structure of starch aggregates into separate starch particles, resulting in the full hydration of starch and water molecules to form denser network structures. The value of peak viscosity and setback decreased in RVA after MW treatment, but the gelatinization temperature remained stable. DSC further proved that moderate MW treatment could reduce the gelatinization enthalpy of starch and made quinoa accessible to gelatinize. However, XRD showed that the crystal structure of starch was preserved, but the crystallinity increased. Finally, low field NMR showed that moderate MW stimulated the full hydration of starch to form denser network structures, while excessive MW treatment made starch partially gelatinize and form rigid structure, resulting in negative texture properties.

Pickering emulsion stabilized by composite-modified waxy corn starch particles

The starch-based Pickering stabilizer has attracted more research interest recently, however, its application in food system is limited due to the low digestibility of raw starch particles. In this study, waxy corn starches were modified with octenyl succinic anhydride and then treated by dry heating at 180 °C for 20-60 min. Pickering emulsions stabilized by the composite-modified starch particles were fabricated, the physical stability, rheology property and microstructure of the emulsions were investigated. The results showed that the composite-modified starches maintained granule structure, their gelatinization temperatures and enthalpy significantly reduced after heat treatment (p < 0.05). Compared with native starch, the composite-modified starches had bigger three-phase contact angles and higher in vitro digestibility, while the relative crystallinity decreased from 32.46% to 24.87%. Pickering emulsions stabilized by composite-modified starch particles had long-term stability up to 300 days. The rheology results showed that all emulsions exhibited pseudoplastic behaviors and had higher storage modulus than loss modulus. Moreover, the viscosities decreased when the starch was roasted for 40 and 60 min. The composite-modified starch particles and few starch macromolecules at oil-water interface stabilized the emulsions collectively. These results provide a new strategy for designing an edible Pickering stabilizer.