Effect of soy protein isolate on physical properties of quinoa dough and gluten-free bread quality characteristics

Effects of soy protein isolate interaction with brown rice starch on the multiscale structure of brown rice bread

BACKGROUND

Gluten-free bread (GFB) has technical bottlenecks such as hard texture, rough taste and low nutrition in practical production. In order to solve these problems, this study used germinated brown rice starch as the main raw material, and investigated the effects of soybean isolate protein (SPI) on the multiscale structure of germinated brown rice starch and bread quality.

RESULTS

A gluten-free rice bread process simulation system was established, and the interaction between SPI and starch in the simulation system was characterized. The result shows that the interaction forces between SPI and germinated brown rice starch were mainly represented by hydrogen bonds, and with the addition of SPI, the crystallinity of starch showed a downward trend. At the same time, when the amount of SPI was 3%, the appearance quality was the best and the specific volume of bread was 1.08 mL g-1. When the amount of SPI was 6%, the texture quality was the best. Compared with the bread without SPI, the hardness of the bread with 6% SPI was reduced by 0.13 times, the springiness was increased by 0.03 times, the color was the most vibrant, the L* value being 1.02 times the original, and the baking loss was reduced to 0.98 times the original.

CONCLUSIONS

The interaction force between SPI and germinated brown rice starch and its effect on bread quality were clarified, and these results inform choices about providing a theoretical basis for the subsequent development of higher-quality GFB. © 2024 Society of Chemical Industry.

Recent microencapsulation trends for enhancing the stability and functionality of anthocyanins: a review

Anthocyanins (ACNs) are water-soluble pigments in various fruits and vegetables known for their high antioxidant activity. They are used as natural food colorants and preservatives and have several medicinal benefits. However, their application in functional foods and nutraceuticals is often compromised by their low stability to heat, oxygen, enzymes, light, pH changes, and solubility issues. Spray drying has emerged as an effective microencapsulation technique to enhance the shelf life, quality, and stability of ACNs. This manuscript reviews the latest scientific developments in spray drying microencapsulation of ACNs-rich fruit extracts. Process optimization and the stability and physicochemical properties of the spray-dried, microencapsulated ACNs-rich powders are discussed. This review also covers functional food and nutraceutical applications and introduces novel encapsulation methods, such as freeze-drying, supercritical carbon dioxide (SC-CO2), coacervation, drum drying, and electrospraying, highlighting their potential in improving the utility of ACNs-rich fruit extracts.

Plant-based proteins: advanced extraction technologies, interactions, physicochemical and functional properties, food and related applications, and health benefits

Even though plant proteins are more plentiful and affordable than animal proteins in comparison, direct usage of plant-based proteins (PBPs) is still limited because PBPs are fed to animals as feed to produce animal-based proteins. Thus, this work has comprehensively reviewed the effects of various factors such as pH, temperature, pressure, and ionic strength on PBP properties, as well as describes the protein interactions, and extraction methods to know the optimal conditions for preparing PBP-based products with high functional properties and health benefits. According to the cited studies in the current work, the environmental factors, particularly pH and ionic strength significantly affected on physicochemical and functional properties of PBPs, especially solubility was 76.0% to 83.9% at pH = 2, while at pH = 5.0 reduced from 5.3% to 9.6%, emulsifying ability was the lowest at pH = 5.8 and the highest at pH 8.0, and foaming capacity was lowest at pH 5.0 and the highest at pH = 7.0. Electrostatic interactions are the main way for protein interactions, which can be used to create protein/polysaccharide complexes for food industrial purposes. The extraction yield of proteins can be reached up to 86-95% with high functional properties using sustainable and efficient routes, including enzymatic, ultrasound-, microwave-, pulsed electric field-, and high-pressure-assisted extraction. Nondairy alternative products, especially yogurt, 3D food printing and meat analogs, synthesis of nanoparticles, and bioplastics and packaging films are the best available PBPs-based products. Moreover, PBPs particularly those that contain pigments and their products showed good bioactivities, especially antioxidants, antidiabetic, and antimicrobial.

Preparation and Characterization of Extruded Yam Starch-Soy Protein Isolate Complexes and Their Effects on the Quality of Dough

Extrusion is a method of processing that changes the physicochemical and rheological properties of starch and protein under specific temperature and pressure conditions. In this study, twin-screw extrusion technology was employed to prepare yam starch-soy protein isolate complexes. The structure and properties of the complexes and their effects on the quality of dough were studied. The results showed changes in the X-ray diffraction, rheology, and in vitro digestibility of the complexes. The extruded starch-protein complex formed an A+V-type crystal structure with the addition of soy protein isolate. A small amount of soy protein isolate could improve the complex's viscoelasticity. As the content of soy protein isolate increased, the content of slow-digesting starch and resistant starch in the complexes increased, and the digestibility decreased. The microstructure of the dough indicated that the network structure of the puffed yam starch-protein complex dough was more uniform than that of the same amount of puffed yam starch. The moisture distribution of the dough showed that with the addition of extruded flour, the closely bound water content of the dough increased, and the weakly bound water content decreased. The hardness, gumminess, chewiness, and resilience of the dough decreased. In conclusion, extruded starch-protein complexes can improve dough quality and provide technical support for the broad application of yam.