In vitro starch digestibility of buckwheat cultivars in comparison to wheat: The key role of starch molecular structure

Comparison of annealing and heat-moisture modification on effects of Tartary buckwheat starch under plasma-activated water condition

This study investigated the effects of plasma-activated water (PAW) assisted annealing and heat-moisture treatment (HMT) on the physicochemical, structural properties, and in vitro digestibility of Tartary buckwheat starch (TBS). The results showed that there were much aggregates on the surface of starch granules under annealing and HMT conditions, it was more pronounced when subjected in PAW. The modified starches showed higher R1047/1022 and pasting temperature, which led to reducing digestibility of TBS. Notably, the highest resistant starch content (71.08 %) was observed with PAW-HMT under the moisture content of 30 %. In addition, all the modified starches remained A type pattern except HMT and PAW-HMT samples, which displayed an A + V type pattern. Therefore, TBS was more sensitive to the combined HMT and PAW treatment. These findings offered valuable insights into the application of PAW combined with thermal treatments to enhance the quality of TBS in the utilization of functional foods.

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.

Research Progress on the Application of Metal Porphyrin Electrochemical Sensors in the Detection of Phenolic Antioxidants in Food

This paper reviews the application of metal porphyrin electrochemical sensors in the detection of phenolic antioxidants in food, focusing on the latest progress and innovative applications in this field. Phenolic antioxidants are widely used in food and can effectively prolong the shelf life of food, but their excessive use may cause potential harm to human health, so the detection of their content is very important. In recent years, electrochemical analysis technology has gradually become an emerging method for quantitative detection of phenolic antioxidants due to its advantages of sensitivity, simplicity and high selectivity. As a new type of sensor, metal porphyrin electrochemical sensors have been widely used in the detection of phenolic antioxidants in food due to their excellent electrochemical performance and high selectivity. By modifying metal nanomaterials, the detection performance of these sensors has been significantly improved. This paper first introduces the basic concepts and physicochemical properties of phenolic antioxidants, analyzes their potential hazards and discusses relevant regulations and limit requirements. Then, the existing analysis methods of phenolic antioxidants are compared, and the development trend of traditional detection methods and new detection technologies is reviewed. Subsequently, the application progress of electrochemical sensors in the detection of phenolic antioxidants is discussed in depth, its working principle is expounded and the research results are summarized. Finally, the innovative applications of metalloporphyrins and their nanocomposites in electrochemical sensors are introduced in detail. The unique advantages of metalloporphyrins in the detection of phenolic antioxidants in food are highlighted, and the future development direction is laid out.

The Effect of Protein-Starch Interaction on the Structure and Properties of Starch, and Its Application in Flour Products

Grains are an energy source for human beings, and the two main components-starch and protein-determine the application of grains in food. The structure and properties of starch play a decisive role in determining processing characteristics, nutritional properties, and application in grain-based foods. The interaction of proteins with starch greatly affects the structure, physicochemical, and digestive properties of the starch matrix. Scientists have tried to apply this effect to create foods tailored to specific needs. Therefore, studying the effect of protein on the structure and properties of starch in the starch-protein complexes will help in designing personalized and improved starch-based food. This paper reviews the latest research about the effects of endogenous and exogenous proteins on the structure and properties of starch, as well as factors influencing the interaction between protein and starch. This includes investigations of the chain and aggregation structure of proteins with starch, as well as assessments of impacts on thermal properties, rheology, gel texture properties, hydration properties, aging, and digestion. In addition, particular examples illustrating the effects of protein-starch interaction on starch properties in various foods are discussed, providing a reference for designing starch-protein foods that are rich in terms of nutrition and easier to process.

Physicochemical, Structural, and Digestive Properties of Green Banana Starch from Five Chinese Mutant Banana Species

This study provides a comprehensive analysis of the physicochemical, structural, and functional properties of starches extracted from five distinct banana varieties. The starches were labeled as follows: 'Nan Tian Huang' starch (NS), 'Da jiao' starch (DS), 'Gui jiao' starch (GS), 'Gong jiao' starch (OS), and 'Hong jiao' starch (HS). The results show that all starches have A-type crystalline structures and contain high levels of resistant starch, ranging from 88.3% to 93.5%. The amylose content ranges from 21.97% to 55.46%. The starches isolated from the five banana varieties are predominantly flat, rod-shaped, and spherical. Particle sizes vary significantly, ranging from 19.75 to 28.65 µm, which contributes to differences in their functional properties. For example, DS demonstrates exceptional functional properties, including high RS content, a low glycemic index, and excellent thermal stability. In contrast, HS starch, despite its high amylose content, exhibits higher enzymatic digestibility and lower freeze-thaw stability. Principal component analysis and correlation analysis revealed that amylose content, thermal properties, and particle morphology are key determinants of the physicochemical and digestive properties of banana starch, emphasizing their interdependence. Additionally, notable differences were observed in the gelatinization properties, thermal characteristics, crystallization, and textural parameters. These findings offer valuable insights into the potential applications of banana starch in functional foods and industrial products, highlighting the importance of starch type in optimizing its functionality.

Mechanism of hydrocolloids effect on buckwheat starch gels from interaction and structural perspectives: A comparative study

Controlling the digestibility and gel properties of Tartary buckwheat starch (TBS) has become a central issue for functional foods. The effects of hydroxypropyl methylcellulose (HPMC), guar gum (GG) and Konjac glucomannan (KGM) on TBS from the interaction and structural perspectives were studied. Three hydrocolloids increased the peak, trough and final viscosity of TBS in a concentration-dependent manner. Dynamic frequency sweeps and flow state tests indicated that the TBS-hydrocolloid systems exhibited gel-like behaviour, and TBS-HPMC was more thixotropic than the other systems. The addition of hydrocolloids significantly enhanced the hardness and chewiness of the TBS gels. The structural analyses revealed that hydrocolloids did not affect the functional groups or crystalline structure of TBS, but did improve the orderliness of the systems. The interaction mechanism confirmed that hydrogen bonds and electrostatic forces are the main forces in the formation of HPMC and TBS-KGM gels; while hydrogen bonds are dominant in TBS-GG gels. Moreover, HPMC, GG and KGM can each delay starch hydrolysis to some extent, with a hydrolysis rate varying from 78.66 % ± 2.81 % to 44.8 % ± 0.35 % at three addition levels. The results can provide both theoretical and practical insights into the glycaemic control of starch and TBS-based jelly foods production.

Effects of exogenous brassinosteroids on the starch structure, physicochemical properties and digestibility of wheat under high-temperature stress at the early grain-filling stage

The starch synthesis of wheat was seriously affected by high temperature stress, which affected its yield and quality. At the same time, plant hormones are often used to regulate crop production and mitigate environmental stress in times of adversity. However, whether Brassinosteroids (BRs) can alleviate the adverse effects of high-temperature stress on wheat starch and its internal mechanism are still unclear. Therefore, a two-year field experiment was carried out from 2020 to 2022 to explore the effects of exogenous BRs spraying on the wheat yield, morphological structure and physicochemical properties of starch under high-temperature stress at the early grain-filling stage. The results showed that exogenous spraying of BRs under high-temperature stress increased the activity of key enzymes involved in starch synthesis, the contents of amylose (25.34 %) and amylopectin (11.57 %) were increased on average in two years, and ultimately increased the yield. On the other hand, BRs increased the number of B-type (49.90 %) and C-type starch granules (23.19 %), decreased the number of A-type starch granules (6.38 %) under high-temperature stress, and reduced the chain length of B1 (5.04 %) and B2 (4.88 %) chains of amylopectin. Moreover, BRs decreased crystallinity (25.40 %), gelatinization enthalpy (4.76 %) and 1047/1022 cm-1 (1.25 %), thereby improving the cooking quality of the starch. Through further analysis of the rheological properties and digestibility of starch, BRs improved the processing quality of starch and increased the content of resistant starch (RS, 15.77 %), which provided insights for the processing and utilization of food. In summary, under high-temperature stress, exogenous BRs increased wheat yield and improved starch quality. We recommend BRs as an effective management measure to mitigate high-temperature stress to cope with future climate change.

Structure and digestibility changes of Indica and japonica waxy rice starch during in vitro pre-digestion

The digestion of starch have been of great interest, yet little is known about the structure changes and structure-digestibility relationships of waxy rice starch during digestion. In this study, waxy rice starch from Indica and Japonica cultivars were in vitro pre-digested for different times, and the changes in their structure and properties were investigated, including granule morphology, chain length distribution, short-range ordered structure, crystallinity, thermal properties, and digestibility. Pre-digested Indica and Japonica waxy rice starch had the characteristics of porous starch, showing similar surface erosion and pores. With the prolongation of pre-digestion time, the amylose content decreased by 0.74 %-2.69 %, the proportion of amylopectin short A chain (DP6-12) and B1 chain (DP13-24) decreased, and the proportion of long B2 (DP25-36) and B3 chain (DP ≥ 37) increased, especially in pre-digested Indica waxy rice starch. The short- and long-range ordered structure of pre-digested starch increased, manifested by an increase in the absorbance ratio at 1047/1022 cm-1, a decrease at 1022/995 cm-1, and an increase in relative crystallinity, leading to higher gelatinization temperature and enthalpy. Pre-digested waxy rice starch had a reduced rapidly digestible starch of 18.27 %-33.93 % and an increased resistant starch of 29.51 %-41.32 %, which will be applied in functional starch and healthy starchy foods.

Starch chain-length distributions affect the processing and digestion characteristics of proso millet starch

Starch chain-length distributions play a key role in regulating the processing and digestion characteristics of proso millet starch. Waxy proso millet starch has higher endothermic enthalpy (13.06-16.73 J/g) owing to its higher relative crystallinity (27.83%-32.04%), while nonwaxy proso millet starch has lower peak viscosity (1.0630-1.1930 Pa∙s) and stronger viscoelasticity owing to its higher amylose content (21.72%-24.34%). Non-waxy proso millet starch exhibited two different digestion phases and its resistant starch content (18.37%-20.80%) was higher than waxy proso millet starch. Correlation analysis showed proso millet starch with longer amylopectin B1 chains and more amylopectin B2 chains exhibited excellent thermal ability and retrograde resistance, whereas proso millet starch with shorter and more amylose medium/long-chains not only reduced the digestion rate and increased the resistant starch content but also exhibited stronger viscoelasticity and excellent retrogradation properties. These results could provide more insights into efficient utilization of proso millet starch.

Effects of amylose and amylopectin fine structure on the thermal, mechanical and hydrophobic properties of starch films

The fine structures of pumpkin, potato, wheat, cassava, and pea starches were determined, followed by an evaluation of how these structures affected the properties of starch films. The structures significantly influenced film properties. Starches with larger molecular weights exhibited greater thermal stability. The tensile strength of starch film was negatively associated with the amylose chain length (r = -0.88, p < 0.05). The chain length distributions of amylose and amylopectin affected the mechanical properties of starch films by influencing structure ordering, supported by the positive correlation between the double helix content and the tensile strength (r = 0.95, p < 0.05). The amylopectin B1, B2, and B3 chains increased film mechanical strength. Conversely, amylopectin A-chains reduced the mechanical strength. The water contact angle was negatively correlated with the B3 chain proportion (r = -0.93, p < 0.05). The pumpkin starch exhibited the highest tensile strength (14.29 MPa), while the wheat starch film showed the highest water contact angle (112°). This study offers valuable insights into the structure-function relationships of starch films, thereby facilitating the acquisition of starch films with enhanced strength and stability through screening or designing starch structures. Consequently, this will expand the application of starch films as packaging materials in various food products.

The importance of starch chain-length distribution for in vitro digestion of ungelatinized and retrograded foxtail millet starch

The digestibility of ungelatinized, short-term retrograded and long-term retrograded starch from foxtail millet was investigated and correlated with starch chain length distributions (CLDs). Some variations in starch CLDs of different varieties were obtained. Huangjingu and Zhonggu 9 had higher average chain lengths of debranched starch and lower average chain length ratios of amylopectin and amylose than Dajinmiao and Jigu 168. Compared to ungelatinized starch, retrogradation significantly increased the estimated glycemic index (eGI), whereas significantly decreased the resistant starch (RS). In contrast, long-term retrograded starches have lower eGI (93.33-97.37) and higher RS (8.04-14.55%) than short-term retrograded starch. PCA and correlation analysis showed that amylopectin with higher amounts of long chains and longer long chains contributed to reduced digestibility in ungelatinized starch. Both amylose and amylopectin CLDs were important for the digestibility of retrograded starch. This study helps a better understanding of the interaction of starch CLDs and digestibility during retrogradation.

Cereal flours with Bacillus coagulans and beta-glucan: Technological properties and sensory acceptability

This study aimed to develop three formulations of cereal flours: control cereal flour (CCF), probiotic cereal flour (PCF), and symbiotic cereal flour (SCF), and porridges from the flours were manufactured as a functional food. No significant differences were observed in the microbiological quality and the color of the flours for 150 days. The technological and functional potential of the flours were variously improved with the addition of Bacillus coagulans as a probiotic and beta-glucan as a prebiotic. The addition of beta-glucan fiber did not change the viability of the probiotic, which was higher than 7.45 log CFU/g for SCF and 7.13 log CFU/g for PCF until the end of the storage period. All porridge samples showed non-Newtonian fluid behavior with pseudoplastic characteristics; and the PCF and SCF porridges differed regarding the parameters of hardness (1.10 to 1.38 N), adhesiveness (5.88 to 8.86 mJ), cohesiveness (0.78 to 0.95) and gumminess (0.93 to 1.52 N) over time. The addition of the beta-glucan prebiotic interfered with these attributes due to its gelling capacity in the presence of water. The PCF obtained the best sensory acceptance scores when compared to the other formulations. The addition of Bacillus coagulans and beta-glucan did not interfere with thermographic behavior. The SCF differed in the observed crystallinity parameters from CCF and PCF, with the presence of larger solids and agglomerates.

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.

Insight to starch retrogradation through fine structure models: A review

The retrogradation of starch is crucial for the texture and nutritional value of starchy foods products. There is mounting evidence highlighting the significant impact of starch's fine structures on starch retrogradation. Because of the complexity of starch fine structure, it is a formidable challenge to study the structure-property relationship of starch retrogradation. Several models have been proposed over the years to facilitate understanding of starch structure. In this review, from the perspective of starch models, the intricate structure-property relationship is sorted into the correlation between different types of structural parameters and starch retrogradation performance. Amylopectin B chains with DP 24-36 and DP ≥36 exhibit a higher tendency to form ordered crystalline structures, which promotes starch retrogradation. The chains with DP 6-12 mainly inhibit starch retrogradation. Based on the building block backbone model, a longer inter-block chain length (IB-CL) enhances the realignment and reordering of starch. The mathematical parameterization model reveals a positive correlation between amylopectin medium chains, amylose short chains, and amylose long chains with starch retrogradation. The review is structured according to starch models; this contributes to a clear and comprehensive elucidation of the structure-property relationship, thereby providing valuable references for the selection and utilization of starch.

Macromolecular, thermal, and nonthermal technologies for reduction of glycemic index in food-A review

Consumers rely on product labels to make healthy choices, especially with regard to the glycemic index (GI) and glycemic load (GL), which identify foods that stabilize blood sugar. Employing both thermal and nonthermal processing techniques can potentially reduce the GI, contributing to improved blood sugar regulation and overall metabolic health. This study concentrates on the most current advances in GI-reduction food processing technologies. Food structure combines fiber, healthy fats, and proteins to slow digestion, reducing GI. The influence of thermal approaches on the physical and chemical modification of starch led to decreased GI. The duration of heating and the availability of moisture also determine the degree of hydrolysis of starch and the glycemic effects on food. At a lower temperature, the parboiling revealed less gelatinization and increased moisture. The internal temperature of the product is raised during thermal and nonthermal treatment, speeds up retrogradation, and reduces the rate of starch breakdown.

Developing high resistant starch content rice noodles with superior quality: A method using modified rice flour and psyllium fiber

The effects of high-resistant starch (RS) content rice flour, psyllium husk powder (PHP), and psyllium powder (PP) on the edible quality and starch digestibility of rice noodles were investigated in this study. High-RS rice noodles showed lower digestibility but poor edible quality. With the addition of PHP and PP, high-RS rice noodles' cooking and texture quality were improved significantly, especially the breakage rates, cooking losses, and chewiness (P < 0.05). Compared to traditional white rice noodle's estimated glycemic index (eGI) of 86.69, the eGI values for 5PHP-RN and 5PHP-2PP-RN were significantly decreased to 66.74 and 65.77, achieving a medium GI status (P < 0.05). This resulted from the high amylose and lipid content in the modified rice flour and psyllium, leading to increase of starch crystallinity. Besides, based on the analysis of Pearson's correlation, it can be found that PHP rich in insoluble dietary fiber (IDF) could improve high-RS noodle cooking and texture quality better, while PP rich in soluble dietary fiber (SDF) can further reduce the RDS content and its starch digestibility. Therefore, utilizing modified rice flour with an appropriate addition of PHP and PP can be considered an effective strategy for producing superior-quality lower glycemic index rice noodles.

The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Amylopectin chain length distributions and amylose content are determinants of viscoelasticity and digestibility differences in mung bean starch and proso millet starch

This study aimed to reveal the underlying mechanisms of the differences in viscoelasticity and digestibility between mung bean starch (MBS) and proso millet starch (PMS) from the viewpoint of starch fine molecular structure. The contents of amylopectin B2 chains (14.94-15.09 %), amylopectin B3 chains (14.48-15.07 %) and amylose long chains (183.55-198.84) in MBS were significantly higher than PMS (10.45-10.76 %, 12.48-14.07 % and 70.59-88.03, respectively). MBS with higher amylose content (AC, 28.45-31.80 %) not only exhibited a lower weight-average molar mass (91,750.65-128,120.44 kDa) and R1047/1022 (1.1520-1.1904), but also was significantly lower than PMS in relative crystallinity (15.22-23.18 %, p < 0.05). MBS displayed a higher storage modulus (G') and loss modulus (G'') than PMS. Although only MBS-1 showed two distinct and discontinuous phases, MBS exhibited a higher resistant starch (RS) content than PMS (31.63-39.23 %), with MBS-3 having the highest RS content (56.15 %). Correlation analysis suggested that the amylopectin chain length distributions and AC played an important role in affecting the crystal structure, viscoelastic properties and in vitro starch digestibility of MBS and PMS. These results will provide a theoretical and scientific basis for the development of starch science and industrial production of low glycemic index starchy food.

Investigating the effect of natural fermentation in modifying the physico-functional, structural and thermal characteristics of pearl and finger millet starch

BACKGROUND

In recent years, millets are often considered an emerging crop for sustainable agriculture. Therefore, millets can be exploited as an alternative source of starch which has many applications ranging from food, packaging, bioplastics, and others. However, starch is seldom used in its native form and is more often modified to enhance its functional properties. In literature, many traditional millet-based food recipes often incorporate a fermentation step before cooking. Therefore, using this traditional knowledge fermentation has been explored as a potential method for modifying millet starch.

RESULTS

Pearl millet (PM) and finger millet (FM) flour were allowed to naturally ferment for 24 h followed by starch extraction. Compared to native (N) starch, water/oil holding capacity and least gelation concentration of fermented (F) starch decreased with no significant change in swelling power. The solubility, paste clarity and in vitro digestibility of starch were significantly affected by fermentation. X-ray diffraction (XRD) data indicates that after fermentation, crystallinity increased while the A-type crystalline structure remained intact. Fourier-transform infrared (FTIR) spectra showed no deletion or addition of any new functional groups. Thermal characterization by differential scanning calorimetry (DSC) showed that the enthalpy of gelatinization of PM starch decreased while that of FM starch increased after fermentation.

CONCLUSION

The results indicate that 24 h natural fermentation had a significant impact on functional properties of starch without altering the structural architecture of starch granules. Therefore, fermentation can be further explored as a low-cost alternative for starch modification. © 2023 Society of Chemical Industry.

Impact of starch chain length distributions on physicochemical properties and digestibility of starches

Changing starch structure at different levels is a promising approach to promote desirable metabolic responses. Chain length distribution (CLD) is among the starch structural characteristics having a potential to determine properties of starch-based products. Therefore, the objective of the current review is to summarize recent findings on CLD and its impact on physicochemical properties and digestion. Investigations undertaken to enhance understanding of starch structure have shown clearly that CLD is a significant determining factor in modulating starch digestibility. Enzymatic modifications and processing treatments alter the CLD of starch, which in turn affects the rate of digestion, but the underlying molecular mechanisms have yet to be fully elucidated. Even though advances have been made in manipulating CLD using different methods and to correlate the changes with various functional properties, in general the area needs further investigations to open new awareness for enhancing healthiness of starchy foods.

Impact of Corn Starch Molecular Structures on Texture, Water Dynamics, Microstructure, and Protein Structure in Silver Carp (Hypophthalmichthys molitrix) Surimi Gel

This study systematically investigates the impact of corn starch molecular structures on the quality attributes of surimi gel products. Employing molecular analyses to characterize corn starch, three amylopectin fractions (A, B1, and B2), categorized by the degree of polymerization ranges (6 < X ≤ 12, 12 < X ≤ 24, and 24 < X ≤ 36, respectively) were specifically focused on. The surimi gel quality was comprehensively assessed through texture profile analysis, nuclear magnetic resonance, scanning electron microscopy, stained section analysis, and Fourier transform infrared spectroscopy. Results indicated the substantial volume expansion of corn amylopectin upon water absorption, effectively occupying the surimi gel matrix and fostering the development of a more densely packed protein network. Starch gels with higher proportions of A, B1, and B2 exhibited improved hardness, chewiness, and bound water content in the resultant surimi gels. The weight-average molecular weight and peak molecular weight of corn starch showed a strong positive correlation with surimi gel hardness and chewiness. Notably, the secondary structure of proteins within the surimi gel was found to be independent of corn starch's molecular structure. This study provides valuable insights for optimizing formulations in surimi gel products, emphasizing the significance of elevated A, B1, and B2 content in corn starch as an optimal choice for crafting dense, chewy, water-retaining surimi gels.

Capillary electromigration methods for food analysis and Foodomics: Advances and applications in the period March 2021 to March 2023

This work presents a revision of the main applications of capillary electromigration (CE) methods in food analysis and Foodomics. Papers that were published during the period March 2021 to March 2023 are included. The work shows the multiple CE methods that have been developed and applied to analyze different types of molecules in foods and beverages. Namely, CE methods have been applied to analyze amino acids, biogenic amines, heterocyclic amines, peptides, proteins, phenols, polyphenols, pigments, lipids, carbohydrates, vitamins, DNAs, contaminants, toxins, pesticides, additives, residues, small organic and inorganic compounds, and other minor compounds. In addition, new CE procedures to perform chiral separation and for evaluating the effects of food processing as well as the last developments of microchip CE and new applications in Foodomics will be also discussed. The new procedures of CE to investigate food quality and safety, nutritional value, storage, and bioactivity are also included in the present review work.

Starch chain-length distributions determine cooked foxtail millet texture and starch physicochemical properties

Starch chain-length distributions play an important role in controlling cereal product texture and starch physicochemical properties. Cooked foxtail millet texture and starch physicochemical properties were investigated and correlated with starch chain-length distributions in eight foxtail millet varieties. The average chain lengths of amylopectin and amylose were in the range of DP 24-25 and DP 878-1128, respectively. The percentage of short amylopectin chains (Ap1) was negatively correlated with hardness but positively correlated with adhesiveness and cohesion. Conversely, the amount of amylose intermediate chains was positively correlated with hardness but negatively correlated with adhesiveness and cohesion. Additionally, the amount of amylose long chains was negatively correlated with adhesiveness and chewiness. The relative crystallinity (RC) of starch decreased with reductions in the length of amylopectin short chains in foxtail millet. Pasting properties were mainly influenced by the relative length of amylopectin side chains and the percentage of long amylopectin branches (Ap2). Longer amylopectin long chains resulted in lower gelatinization temperature and enthalpy (ΔH). The amount of starch branched chains had important effects on the gelatinization temperature range (ΔT). These results can provide guidance for breeders and food scientists in the selection of foxtail millet with improved quality properties.

Modulating the glycemic response of starch-based foods using organic nanomaterials: strategies and opportunities

Traditionally, diverse natural bioactive compounds (polyphenols, proteins, fatty acids, dietary fibers) are used as inhibitors of starch digestive enzymes for lowering glycemic index (GI) and preventing type 2 diabetes mellitus (T2DM). In recent years, organic nanomaterials (ONMs) have drawn a great attention because of their ability to overcome the stability and solubility issues of bioactive. This review aimed to elucidate the implications of ONMs in lowering GI and as encapsulating agents of enzymes inhibitors. The major ONMs are presented. The mechanisms underlying the inhibition of enzymes, the stability within the gastrointestinal tract (GIT) and safety of ONMs are also provided. As a result of encapsulation of bioactive in ONMs, a more pronounced inhibition of enzymes was observed compared to un-encapsulated bioactive. More importantly, the lower the size of ONMs, the higher their inhibitory effects due to facile binding with enzymes. Additionally, in vivo studies exhibited the potentiality of ONMs for protection and sustained release of insulin for GI management. Overall, regulating the GI using ONMs could be a safe, robust and viable alternative compared to synthetic drugs (acarbose and voglibose) and un-encapsulated bioactive. Future researches should prioritize ONMs in real food products and evaluate their safety on a case-by-case basis.

Effects of HMW-GSs at Glu-B1 locus on starch-protein interaction and starch digestibility during thermomechanical processing of wheat dough

BACKGROUND

The composition of glutenin protein significantly affects protein-starch interactions and starch digestion characteristics in wheat dough matrices. To elucidate the effects of high molecular weight glutenin subunits at the Glu-B1 locus on dough processing quality, the detailed structural changes of protein, starch, and their complexes were compared in Mixolab dough samples of two near isogenic lines 7 + 8 and 7 + 9.

RESULTS

The results showed that the degree of protein aggregation increased continuously during dough processing, as did the destruction and rearrangement of the gluten network. Compared to 7 + 8, the stronger and more stable protein network formed in 7 + 9 dough induced intensive interactions between protein and starch, primarily through hydrogen bonds and isomeric glycosidic bonds. In 7 + 9 dough, the more compact and extensive protein-starch network significantly inhibited starch gelatinization during dough pasting, while during the dough cooling stage [from C4 (82.8 °C) to C5 (52.8 °C)], more protein-starch complexes composed of monomeric proteins and short-chain starch were generated, which remarkably inhibited starch retrogradation. All protein-starch interactions in the 7 + 9 dough improved the starch digestion resistance, as reflected by the high content of resistant starch.

CONCLUSION

The more extensive and intensive protein-starch interactions in the 7 + 9 dough inhibited the gelatinization and enzymatic hydrolysis of starch, thereby producing more slowly digestible starch and resistant starch. These findings demonstrate the feasibility of optimizing the texture and digestibility of wheat-based food products by regulating the behavior and interactions of proteins and starch during dough processing. © 2022 Society of Chemical Industry.

Physicochemical properties and in vitro digestibility of highland barley starch with different extraction methods

The objective of this study was to compare the structural, thermal, rheological and digestive properties of highland barley starch (HBS) by different extraction methods. Five techniques were used to extract HBS: Alkali extraction, Ultrasound extraction, double enzyme extraction (DE), three enzyme extraction (TE) and ultrasonic assisted TE (U-TE). The results indicated that the Ultrasound extracted HBS had fewer Maltese crosses, lower molecular weight (Mw), and higher content of damaged starch (P < 0.05). Meanwhile, DE extracted HBS had higher Mw, and the content of short amylopectin than that of Alkali extracted HBS (P < 0.05). Additionally, the DE extracted HBS showed the highest relative crystallinity and good short-range ordered structure, which led to the outcome of stronger thermal stability and higher values of G' and G'' (P < 0.05). These results indicated that enzymatic extraction could better protect the resistance of HBS by protecting its physicochemical properties.

Extraction and characterization of waxy and normal barley β-glucans and their effects on waxy and normal barley starch pasting and degradation properties and mash filtration rate

Interactions between β-glucan and starch influence the health benefits of barley-based foods and barley brewing performance. Here, we characterized β-glucans from waxy and normal barley varieties and compared the effects of different β-glucans on the pasting and degradation of waxy and normal barley starches as well as the filterability of mashes from unmalted waxy and normal barley. Waxy barley Zangqing18 β-glucan displayed more compact micrographic features, higher molecular weight, larger particle size, higher thermal decomposition temperature and lower rheological viscosity than normal barley Zangqing2000 β-glucan. β-Glucan not only significantly decreased the pasting viscosities of waxy and normal starches but also lowered the pasting temperatures and peak times of normal starch, likely by inhibiting granule swelling and disrupting the integrity of the continuous phase. β-Glucan also decreased in vitro digestion extent of starch and increased the resistant starch. The unmalted waxy barley had a mash filtration rate much faster than normal barley because starch and β-glucan in waxy barley were rapidly and completely digested and formed more open filter passages. The effects of β-glucan on starch properties varied with the types and contents of β-glucans, whilst the types of starches showed more significant effects. CHEMICAL COMPOUNDS STUDIED: β-Glucan (Pubchem CID: 439262); Amylopectin (Pubchem CID: 439207); Starch (Pubchem CID: 156595876).

Starch parameters and short-term temperature fluctuations - Important but not yet in focus?

Plants are regularly challenged by unfavorable environmental conditions. As climate change continues, adverse situations such as drought, heat, and cold are expected to increase and become more severe. Most starchy crops are affected by such stresses. In recent years, researchers have made many new discoveries about starch metabolism in general and also on granule structure, including effects on starch following longer-term temperature stresses. However, in this study, we focus on short-term temperature stress on storage starch granule properties. Here our knowledge is less and it is likely that also short-term temperature stresses can affect various starch parameters. Therefore, we see a need for this type of analysis and discuss the matter in more detail and we conclude that a deeper knowledge particularly of starch granule parameters could allow targeted breeding of cultivars that exhibit different starch characteristics as a result of short-term stress. For these reasons, we are convinced that more comprehensive research on the effects of short-term temperature stress on starch granule characteristics is important, necessary, and timely.

Impact of Rutin and Other Phenolic Substances on the Digestibility of Buckwheat Grain Metabolites

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is grown in eastern and central Asia (the Himalayan regions of China, Nepal, Bhutan and India) and in central and eastern Europe (Luxemburg, Germany, Slovenia and Bosnia and Herzegovina). It is known for its high concentration of rutin and other phenolic metabolites. Besides the grain, the other aboveground parts of Tartary buckwheat contain rutin as well. After the mixing of the milled buckwheat products with water, the flavonoid quercetin is obtained in the flour-water mixture, a result of rutin degradation by rutinosidase. Heating by hot water or steam inactivates the rutin-degrading enzymes in buckwheat flour and dough. The low buckwheat protein digestibility is due to the high content of phenolic substances. Phenolic compounds have low absorption after food intake, so, after ingestion, they remain for some time in the gastrointestinal tract. They can act in an inhibitory manner on enzymes, degrading proteins and other food constituents. In common and Tartary buckwheat, the rutin and quercetin complexation with protein and starch molecules has an impact on the in vitro digestibility and the appearance of resistant starch and slowly digestible proteins. Slowly digestible starch and proteins are important for the functional and health-promoting properties of buckwheat products.

Butyl Group Distribution, Intestinal Digestion, and Colonic Fermentation Characteristics of Different Butyrylated Starches

Despite being a promising butyrate carrier, butyrylated starch remains poorly understood in terms of the correlation between starch structure and fermentation characteristics. Herein, three butyrylated starches derived from different botanical sources were prepared with a similar degree of substitution. Raman microscopy and water contact angle analysis suggested that a relatively large proportion of butyl group substitutions occurred within the interior of butyrylated waxy maize starch (B-WMS) granules. In vitro digestion results showed that branch points provided butyl groups with a specific protection from enzymatic hydrolysis, whereas butyl groups significantly increased the resistant starch content of butyrylated starch. Moreover, the porous morphology with less distributed butyl groups on the granular surface contributed to a faster fermentation rate in B-WMS. The current study reveals the influence of botanical origin on butyl group distribution, which in turn plays a pivotal role in regulating the intestinal digestion and colonic fermentation of butyrylated starch.

Enzymes-Assisted Extraction of Plants for Sustainable and Functional Applications

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers' demands while searching for 'clean label' food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were used for enhancing production yield with mild and not hazardous applications. However, enzyme specificity, activity, plant origin and characteristics, ratio, and extraction conditions differ depending on the goal. As a result, researchers have gained interest in enzymes' ability to cleave specific bonds of macroelements and release bioactive compounds by enhancing value and creating novel derivatives in plant extracts. The extract is enriched with reducing sugars, phenolic content, and peptides by disrupting lignocellulose and releasing compounds from the cell wall and cytosolic. Nonetheless, depolymerizing carbohydrates and using specific enzymes form and release various saccharides lengths. The latest studies show that oligosaccharides released and formed by enzymes have a high potential to be slowly digestible starches (SDS) and possibly be labeled as prebiotics. Additionally, they excel in new technological, organoleptic, and physicochemical properties. Released novel derivatives and phenolic compounds have a significant role in human and animal health and gut-microbiota interactions, affecting many metabolic pathways. The latest studies have contributed to enzyme-modified extracts and products used for functional, fermented products development and sustainable processes: in particular, nanocellulose, nanocrystals, nanoparticles green synthesis with drug delivery, wound healing, and antimicrobial properties. Even so, enzymes' incorporation into processes has limitations and is regulated by national and international levels.

A review of wheat starch analyses: Methods, techniques, structure and function

Wheat starch has received much attention as an important source of dietary energy for humans, an interesting carbohydrate and a polymeric material. The understanding of the structure and function of wheat starch has always been accompanied by newer technological tools. On the one hand, the general knowledge of wheat starch is constantly being enriched. On the other hand, an increasing number of studies are trying to add new insights to what is already known from two frontier perspectives, namely, wheat starch supramolecular structures and wheat starch fine structures (CLDs). This review describes the structure and function of wheat starch from the perspective of wheat starch analysis techniques (instruments).