Effect of protein on the gelatinization behavior and digestibility of corn flour with different amylose contents

Development of in vitro oral processing model for different rice: Effects of saliva volume and chewing time on physicochemical properties of rice boluses

The in vitro model is widely preferred for digestion research due to its simplicity, reproducibility, and ethical advantages. However, the differences between in vivo and in vitro digestion present challenges. This study first developed an in vitro oral processing system to explore the influence of saliva volume and chewing time on the physicochemical properties of japonica rice (JR), indica rice (IR), and waxy rice (WR). The results revealed that both saliva volume and chewing time significantly influenced properties like texture, particle size, starch hydrolysis, protein distribution, and microstructure, with chewing time exerting a greater impact. Starch hydrolysis was closely linked to particle size, with fragmentation being the primary factor. An artificial neural network (ANN) model was used to effectively correlate the in vitro simulation conditions with physiological characteristics. By integrating in vivo data, optimized simulation conditions were determined for each rice type: JR-saliva 197.85 ± 21.42 mg/g, chewing 21.02 ± 1.51 s; IR-saliva 198.64 ± 22.41 mg/g, chewing 22.36 ± 0.45 s; WR-saliva 127.11 ± 21.63 mg/g, chewing 14.74 ± 0.90 s.

Extrusion-aided interaction of rice starch with whey protein isolate: Synergistic influence on physicochemical properties and in vitro starch digestibility characteristics

Synergistic influence of extrusion conditions and whey protein isolate (WPI) incorporation on glycemic response and physicochemical characteristics of rice starch was studied. Box-Behnken Design was used to evaluate effect of process variables (rice starch:WPI ratio; feed moisture and barrel temperature) on quality characteristics of resistant starch-rich, low GI extruded snacks (RSLG-E). Optimum conditions for development of RSLG-E were WPI:18.30 %, feed moisture:20 % and barrel temperature:120 °C. FTIR spectroscopy showed maximum peaks at 1615 cm-1 and 1540 cm-1 corresponding to presence of amide group; however, such band was absent in control. Thermal analysis indicated significantly higher transition temperatures in RSLG-E than control. Expansion ratio (3.79 ± 0.17) and overall acceptability (4.48 ± 0.05) were found to be significantly lower in RSLG-E. In vitro digestibility indicated significantly lower very rapidly digestible starch (2.08 ± 0.03 %) and rapidly digestible starch (68.49 ± 1.07 %) in RSLG-E than control. Digestible starch (86.85 ± 0.97 %), starch hydrolysis rate (58.72 ± 0.97 %) and slowly digestible starch (72.61 ± 0.82 %) were lower in control.

Evaluation of amylose content: Structural and functional properties, analytical techniques, and future prospects

Amylose content (AC) is critical in evaluating starch properties, significantly influencing the food industry and human nutrition. Although amylose is not completely linear, its unique structure makes it a key research focus across various scientific fields. Understanding amylose's structural and functional properties is essential for its applications in medical, nutritional, and industrial sectors. Accurate determination of AC, from simple qualitative assessments to precise quantitative measurements, is vital for effectively processing and using starch-rich products. The choice of AC determination method depends on the specific application and the required accuracy and detail. This review summarizes amylose's structural and functional characteristics and recent advancements in qualitative and quantitative AC determination techniques. It also provides insights into future trends and prospects for these technologies, emphasizing the need for more rapid, convenient, accurate, and customizable methods. In conclusion, advancements in amylose determination should enhance accuracy, speed, and ease of use to improve quality control and applications across various sectors while expanding our understanding of amylose and its functionalities.

Supramolecular structure and in vitro digestive properties of plasma-treated corn starches varying in amylose content

The effects of plasma treatment on the multi-scale structure and in vitro digestibility of maize starch with different amylose contents were systematically evaluated. The results demonstrated that all maize starches' molecular weights (MW) decreased when treated with plasma, among which the MW of waxy maize starch displayed the largest reduction. Plasma treatment led to an increase in the thickness of the semi-crystalline lamellae and double helix proportions of waxy and normal maize starches. However, high-amylose maize starch presented a less ordered structure by plasma treatment. Additionally, larger pores and channels were observed on the surface of plasma-treated waxy and normal maize starch granules. Moreover, deposits were displayed on the surface of high-amylose maize starch granules. These changes increased the in vitro digestibility and hydrolysis rate of three starches after plasma treatment. Notably, plasma treatment caused diverse alterations in the structure and functionality of maize starch varying in amylose content, leading to maize starch with better digestibility, therefore being used as an ingredient for functional foods.

Study on the Mechanism of Effect of Protein on Starch Digestibility in Fermented Barley

Previous studies have shown that fermented barley has a lower digestion rate. However, it remains unclear whether the antidigestibility of starch in fermented barley is affected by other nonstarch components. In this paper, the removal of protein, lipid, and β-glucan improved the hydrolysis rate of starch and the protein showed the greatest effect. Subsequently, the inhibitory mechanism of protein on starch digestion was elucidated from the perspective of starch physicochemical properties and structural changes. The removal of protein increased the swelling power of starch from 10.09 to 11.14%. The short-range molecular ordered structure and the helical structure content decreased. The removal of protein reduced the coating and particle size of the starch particles, making the Maltese cross more dispersed. In summary, protein in fermented barley enhanced the ordered structure of starch by forming a physical barrier around starch and prevented the expansion of starch, which inhibited the hydrolysis of starch.

Effects of improver on the quality of frozen Chinese sweet rice wine dough: Water status, protein structure and flavor properties

In the study, a sweet wine koji (YQ-5) was successfully selected to make frozen Chinese sweet rice wine dough (F-CD) for flavor enrichment. Subsequently, the effects of single improver (SI: xanthan gum, potassium carbonate, antifreeze protein, diacetyl tartaric esters of monoglycerides and composite improver (XPADG: Four improvers mixed in proportion) on the texture, rheological properties, microstructure, water status, protein secondary structure, volatile flavor substances and sensory properties of F-CD during frozen storage were investigated. The results indicated that XPADG slowed the increase in freezable water and water mobility in the dough, giving dough the most stable rheological properties and minimizing the damage of freezing to the secondary structure and microstructure of proteins. Besides, GC-QTOF/MS analysis showed that XPADG may facilitate the retention of flavoring substances in F-CD after storage for 6 days. Finally, the sensory evaluation showed that XPADG imparted good sensory properties to the product after freezing for 6 days.

Effects of protein morphological structures on the cereal processing, sensorial property and starch digestion: a review

In cereals, the protein body and protein matrix are usually two morphological protein structures. However, processing treatments can affect protein structures, change protein bodies into the matrix, or induce a change in the matrix structure; therefore, the processing-induced matrix was listed as the third morphological structure of the protein. Previous research on the effect of proteins was mainly based on protein content and composition, but these studies arrived at different conclusions. Studying the effect of protein morphological structures on sensorial property and starch digestion can provide a theoretical basis for selecting cultivars with high sensorial property and help produce low-glycemic index foods for people with diabetes, controlling their postprandial blood sugar. This study aimed to review the distribution and structure of protein bodies, protein matrices, and processing-induced matrices, as well as their influence on cereal sensorial property and starch digestion. Therefore, we determined the protein morphological structures in different cereal cultivars and summarized its impact. Protein bodies mainly have steric stabilization effects on starch gelatinization, whereas the protein matrix serves as a physical barrier surrounding the starch to inhibit water absorption and α-amylase. Processing can change protein morphological structures, enabling protein bodies to act as a physical matrix barrier.

Functional foods with a tailored glycemic response based on food matrix and its interactions: Can it be a reality?

Functional foods are considered the future of nutrition because they benefit human health and environmental sustainability. They offer natural solutions for managing post-prandial glycemia and its long-term consequences. Therefore, understanding the composition and inherent dynamics of the functional food matrix (FM) is crucial. Within the FM, components like proteins, fats, carbohydrates, phenolic compounds, fibres, and minor elements interact dynamically, highlighting how individual components within the system behave. This review highlights the significance of diverse FM interactions in modulating inherent glycemic potential (IGP). These interactions comprise major binary, ternary, quaternary interactions, and minor interactions, in contemporary functional food formulations that include starch-derived additives, biopeptides, and flavouring agents. The starch quality matrix (SQM), a prediction model for customised functional foods with low IGP, has been briefed as a pilot concept. We also investigate the impact of these interactions on gut health, fill in the knowledge gaps, and provide recommendations for further study.

A review of endogenous non-starch components in cereal matrix: spatial distribution and mechanisms for inhibiting starch digestion

As compared with exogenous components, non-starch components (NSCS), such as proteins, lipids, non-starch polysaccharides (NSPs), and polyphenols, inherently present in cereals, are more effective at inhibiting starch digestibility. Existing research has mostly focused on complex systems but overlooked the analysis of the in-situ role of the NSCS. This study reviews the crucial mechanisms by which endogenous NSCS inhibit starch digestion, emphasizing the spatial distribution-function relationship. Starch granules are filled with pores/channels-associated proteins and lipids, embedding in the protein matrix, and maintained by endosperm cell walls. The potential starch digestion inhibition of endogenous NSCS is achieved by altering starch gelatinization, molecular structure, digestive enzyme activity, and accessibility. Starch gelatinization is constrained by endogenous NSCS, particularly cell wall NSPs and matrix proteins. The stability of the starch crystal structure is enhanced by the proteins and lipids distributed in the starch granule pores and channels. Endogenous polyphenols greatly inhibit digestive enzymes and participate in the cross-linking of NSPs in the cell wall space, which together constitute a physical barrier that hinders amylase diffusion. Additionally, the spatial entanglement of NSCS and starch under heat and non-heat processing conditions reduces starch accessibility. This review provides novel evidence for the health benefits of whole cereals.

Effect of different screw speeds on the structure and properties of starch straws

To illustrate the action mechanism of screw speed on the performance of starch-based straws during the extrusion process, starch-based straws at different screw speeds were prepared using a twin-screw extruder and the structures and characteristics were compared. The results indicated that as screw speeds improved from 3 Hz to 13 Hz, the A chain of amylopectin increased from 25.47 % to 28.87 %, and the B3 chain decreased from 6.34 % to 3.47 %. The absorption peak of hydroxyl group shifted from 3296 cm-1 to 3280 cm-1. The relative crystallinity reduced from 13.49 % to 9.89 % and the gelatinization enthalpy decreased from 3.5 J/g to 0.2 J/g. The performance of starch straws did not increase linearly with increasing screw speeds. The starch straw produced at screw speed of 7 Hz had the largest amylose content, the highest gelatinization temperature, the minimum bending strength, and the lowest water absorption rate in hot water (80 °C). Screw speed had a remarkable impact on the mechanical strength, toughness and hydrophobicity of starch-based straws. This study revealed the mechanism of screw speed on the mechanical strength and water resistance of starch straws in the thermoplastic extrusion process and created the theoretical basis for the industrial production of starch-based straws.