Spray drying is used in the food industry to convert liquids into dry powders. The effect of the addition of salt ions before spray drying to improve the heat- and cold-induced gel properties of soy protein isolate (SPI) was investigated. Certain concentrations of Na⁺ (0.005–0.01 M), Mg²⁺ (0.005 M), and Ca²⁺ (0.005 M) significantly increased the hardness, springiness, cohesiveness, chewiness, gumminess, resilience, and water holding capacity of the heat- and cold-induced gels. This effect arises predominantly due to the functional groups buried in the protein matrix that are partially exposed to improve the interactions between the protein molecules. The main interactions that promoted gel formation and maintained the three-dimensional structure of the heat- and cold-induced gels were hydrophobic and disulfide interactions. Analysis using scanning electron microscopy showed that the heat- and cold-induced gels were uniform, had smooth surfaces, and had smaller pores with added Na⁺ (0.01 M), Mg²⁺ (0.005 M), and Ca²⁺ (0.005 M). The results indicate that we might broaden the applications of SPI by simulating the industrial gel manufacturing process for products such as fish balls and chiba tofu. Overall, adding salt ions before spray drying could offer great potential for the development of SPI with enhanced functionality suitable for comminuted meat products.

This study examined the ability of cavitation jet processing to regulate the oxidation concentrations with 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH) (0.2, 1, and 5 mmol/L) and the structure and emulsification of soy protein isolate (SPI). The tested properties included particle size distribution, hydrophobic properties (sulfhydryl group (SH) and disulfide bond (S-S) contents, surface hydrophobicity (H₀)), emulsifying properties (particle size and ζ-potential of emulsions, emulsification activity index (EAI), and emulsification stability index (ESI)), as well as conformational characteristics. The high shear force of cavitation jet treatment reduced the particle size of oxidized SPI and distributed uniformly. Cavitation jet (90 MPa)-treated SPI (AAPH with 1 mmol/L) demonstrated a high H₀ (4688.70 ± 84.60), high EAI (71.78 ± 1.52 m²/g), and high ESI (86.73 ± 0.97%). The ordered secondary structure (α-helix and β-turn content) of SPI was enhanced by the cavitation jet. Meanwhile, the distribution of SPI-oxidized aggregates was observed under an atomic force microscope. Therefore, cavitation jet processing combined with oxidation treatment is an effective method to improve the characteristics of SPI and has potential industrial application prospects.

To enable a wider utilization of co–products from beer processing and minimize the negative effect of added grain on bread quality, flavor, and other attributes, brewer’s spent grains (BSG) are processed through microwave pretreatment, and then the microwave–treated BSG (MW–BSG) is added to bread. So far, there has been no investigation on the effect of microwave–pretreated BSG on bread quality and flavor. In this study, we examined the effects of diverse microwave treatment variables on the physicochemical structure of BSG and explored the consequences of MW–BSG on the quality and flavor of bread. The results showed that soluble dietary fiber and water–soluble protein levels in MW–BSG increased significantly (144.88% and 23.35%) at a 540 W microwave power, 3 min processing time, and 1:5 material–liquid ratio of BSG to water. The proper addition of MW–BSG positively affected the bread texture properties and color, but excessive amounts led to an irregular size and distribution of the bread crumbs. The result of electronic nose and HS–SPME–GC–MS analyses showed that the addition of MW–BSG modified the odor profile of the bread. A sensory evaluation showed mean scores ranging from 6.81 to 4.41 for bread containing 0–10% MW–BSG. Consumers found a maximum level of 6% MW–BSG acceptable. This study endeavors to decrease environmental contamination caused by brewing waste by broadening the methods by which beer co–products can be utilized through an innovative approach.