The impact of gliadin and glutenin on the formation and structure of starch-lipid complexes

Regulation of ice crystal growth in frozen dough: From the effect of gluten and starch fractions interaction on water binding - A review

The formation and growth of ice crystals are critical factors affecting the quality of frozen dough. Gluten and starch are the primary components of dough, and their hydration properties and effects on dough structure are crucial in determining the type of ice crystals formed. Gliadins, glutenins, A-type starch, and B-type starch are their refined components, each with distinct hydration properties and impact on dough structure. This review examines the structural properties and hydration properties of protein and starch components in frozen dough, as well as their individual and interactive influences on water absorption and the structural properties of frozen dough. Additionally, it explores changes at different structural levels during the interaction between protein and starch components in frozen dough. The review provides theoretical support for wheat breeding aimed at frozen flour products, ultimately contributing to the improvement of frozen dough quality and final product outcomes.

New insights into rice starch-gallic acid-whey protein isolate interactions: Effects of multiscale structural evolution and enzyme activity on starch digestibility

In starch-based food where proteins and polyphenols coexist, the impact of protein on the inhibition of starch digestion by polyphenols is unclear. Therefore, the aim of this study was to investigate the impact of whey protein isolate (WPI) on the inhibition of rice starch digestion by gallic acid (GA) from the aspects of multiscale structure and enzyme activity. Rice starch-gallic acid-whey protein isolate complex (RS-GA-WPI) was formed predominantly by hydrogen bonding and hydrophobic interactions. Compared to rice starch-gallic acid complex (RS-GA), RS-GA-WPI exhibited higher short-range ordering and thermal stability, and lower relative crystallinity. Fluorescence spectra and molecular docking showed that the interactions between GA and WPI weakened the hydrogen bond between GA and enzyme active site, so that WPI significantly reduced the enzyme inhibitory activity of GA. The above factors led to the result that the presence of WPI weakened the inhibitory effect of GA on starch digestibility. RS-GA-WPI showed higher starch digestibility and lower resistant starch content compared to RS-GA. This study provided a new understanding of starch digestion mechanism in starch-polyphenol-protein coexistence system.

Physicochemical and microstructural properties of frozen cooked noodles during frozen storage affected by enzymatically interesterified soybean oil-based plastic fat

The quality deterioration of frozen cooked noodles (FCNs) during frozen storage remains a challenging problem, primarily characterized by a decline in textural performance. The objective of this study was to investigate the underlying mechanism responsible for the improvement in FCNs quality by utilizing enzymatically interesterified soybean oil-based plastic fat (EIPF). During the 12-week frozen storage, an improvement in hardness, from 3421.44 g to 3981.91 g, and a decrease in adhesiveness, water absorption rate, and cooking loss, from 177.49 g.s to 153.54 g.s, 80.46 % to 70.43 %, and 2.86 % to 2.16 %, respectively, were observed after adding 1 % of EIPF. The results demonstrated that 1 % EIPF significantly (P < 0.05) mitigated the decline in the quality of FCNs. Additionally, EIPF effectively restrained the transformation and migration of water and resulted in decrease in SDS-soluble gluten content and SH/S-S ratio in FCNs during frozen storage. The addition of 1 % EIPF increased α-helixes and decreased random coils, indicating greater network stability. Microscopic observation further confirmed that the addition of EIPF promoted the formation of dense gluten network. The current study positions EIPF as a promising additive for enhancing the quality of FCNs, thereby promoting its application in food industry.

The impact of addition of pearl millet starch-germ complex in white bread on nutritional, textural, structural, and glycaemic response: Single blinded randomized controlled trial in healthy and pre-diabetic participants

The rise of pre-diabetes at the global level has created a significant interest in developing low glycaemic index food products. The pearl millet is a cheaper source of starch and its germ contains significant amount of protein and fat. The complexing of pearl millet starch and germ by dry heat treatment (PMSGH) resulted an increase in the resistant starch content upto 45.09 % due to formation of amylose-glutelin-linoleic acid complex. The resulting pearl millet starch germ complex was incorporated into wheat bread at 20, 25, and 30 %. The PMSGH incorporated into bread at 30 % reduced the glycaemic index to 52.31. The PMSGH incorporated bread had significantly (p < 0.05)increased in the hardness with a reduction in springiness and cohesiveness. The structural attributes of the 30 % PMSGH incorporated bread revealed a significant (p < 0.05)increase in 1040/1020 cm-1 ratio and relative crystallinity. The consumption of functional bread incorporated with pearl millet starch germ complex reduced blood glucose levels and in vivo glycaemic index in healthy and pre-diabetic participants when compared to white bread. Hence, the study showed that the incorporation of pearl millet starch-germ complex into food products could be a potential new and healthier approach for improving dietary options in pre-diabetes care.

Interaction of high amylose corn starch with polyphenols: Modulating the stability of polyphenols with different structure against thermal processing

Polyphenols are known to undergo thermal degradation and their bioactivity is reduced. In this study, the thermal degradation of polyphenols was modulated by the complexation between polyphenols and high amylose corn starch (HACS). The inclusion complex between ferulic acid with hydrophobic group methoxy and HACS had the highest encapsulation efficiency (EE = 26.15 %), loading efficiency (LE = 2.38 %) and thermal stability (DPPH radical scavenging activity was reduced by only 5.99 % after baking). After complexing with HACS, protocatechuic acid with ortho-position hydroxyl group had a higher encapsulation rate and thermal stability than 3, 5-dihydroxybenzoic acid with meta-position hydroxyl. In addition, soy isoflavone with the higher logarithmic value of octanol-water partition coefficient (Log P = 3.66) resulted in higher encapsulation rate and thermal stability than naringenin (Log P = 2.11). The results suggest that the complexation between polyphenols and starch protects the bioactivity of polyphenols and improves the processing suitability of polyphenols.

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

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

Influence of Storage Temperature on Starch Retrogradation and Digestion of Chinese Steamed Bread

Chinese steamed bread (CSB), which is widely consumed in East Asia, usually undergoes storage before consumption, but it is unclear how different storage temperatures affect CSB starch retrogradation and digestion properties, which are important for consumers. CSB was stored for 2 days at 25 °C, 4 °C, -18 °C, 4 °C/25 °C temperature cycling (i.e., 24 h at 4 °C, followed by 24 h at 25 °C) and -18 °C/ 25 °C temperature cycling. The results revealed for the first time that more orderly starch double helices are formed when CSB was stored at 4 °C or 4 °C/25 °C. Storage under -18 °C produced lower amounts of, but more heterogenous, starch double helices, with fewer B-type, but more V-type, crystallites. Compared to other storage temperatures, more long-range intermolecular interactions formed between the starch and protein at 4 °C or 4 °C/25 °C. CSB samples showed the slowest starch digestibility when stored at 4 °C. The impact of storage temperature on the starch retrogradation properties and digestibility of CSB also depended on the wheat variety, attributed to differences in the starch molecular structure. These results have significance and practical applications to help the CSB food industry to control starch retrogradation and digestibility. For example, CSB could be stored at 4 °C for 2 days in order to reduce its starch digestibility.

Effect and mechanism of glycerol monostearate dimer (GMS-D) and baking-treatment on the structure, in vitro digestion of gelatinized potato starch-GMS-D

With the increasing progress of society and in-depth scientific research, dietary regulations, especially sustained glucose releases, are regarded as an effective and significant way to lighten or even cut the emergence of diabetes. In this research, the starch-lipid complex gelatinized potato starch-glycerol monostearate dimer (GPS-GMS-D) was developed to provide a low-glycemic index functional food component for type 2 diabetes. Briefly, the higher complexation index (CI, 71.02%), lower rapidly digestible starch (RDS, 35.57%), and lower estimated glycemic index (eGI, 52.34%) were referred to as GPS-GMS-D. It was assumed that the solid V-type crystal structure, induced with the helix between GMS-D and GPS due to high amylose, high saturation, and low steric hindrance, contributed to the lower digestibility. In addition, baking treatment for 5 min was systematically exerted to improve the flavor of GPS-GMS-D with a relatively high CI (59.98%) and low eGI (54.15%). It was believed that rapid dehydration and close interaction during baking treatment could slow down the decomposition of GPS-GMS-D and conversions of starch fractions. Therefore, these results suggested that the as-developed GPS-GMS-D was a promising low GI functional dietary food component for diabetes mellitus, and a suitable baking post-thermal treatment was successfully proposed to enhance the flavor of GPS-GMS-D. PRACTICAL APPLICATION: The higher amylose and solid V-type crystal structure in gelatinized potato starch-glycerol monostearate dimer (GPS-GMS-D) would induce the formation of slowly digestive starch (SDS) and resistant starch (RS) to suppress enzymatic hydrolysis. Moreover, the flavor of GPS-GMS-D was enhanced with appropriate and moderate thermal processing (baking), which was likely to improve the quality of life of a person with diabetes. Thus, we believe that GPS-GMS-D is a promising functional food component for diabetes mellitus.

Patterning Large-Scale Nanostructured Microarrays on Coverslip for Sensitive Plasmonic Detection of Aqueous Gliadin Traces

User-friendly devices for detecting low gliadin content in commercial foods are of extreme importance for people with gluten diseases. With this concern, the present work proposes a rapid and sensitive optical nanostructured microarrays platform for the detection of gliadin using specific anti-gliadin IgG antibodies immobilized on annealed gold nanostructures (AuNPs) obtained after the high annealing process (550 °C) of gold thin films evaporated on commercial glass coverslips. Localized Surface Plasmon Resonance (LSPR) immunosensing of gliadin in the range of 0.1 ppm to 1000 ppm is successfully achieved. In addition, the biofunctionalization protocol was used for gluten screening in five food complex products.