Influence of heat treatment before and/or after high-pressure homogenization on the structure and emulsification properties of soybean protein isolate.

This study investigates the effects of heat treatment before high-pressure homogenization (HHPH) and heat treatment after high-pressure homogenization (HPHH) at different pressures (20, 60, and 100 MPa) on the structural and emulsification properties of soy protein isolate (SPI). The results indicate that HHPH treatment increases the surface hydrophobicity (H0) of the SPI, reduces ß-fold and irregular curls, leading to the formation of soluble aggregates, increased adsorbed protein content, and subsequent improvements in emulsification activity index (EAI) and emulsion stability index (ESI). In contrast, the HPHH treatment promoted the exchange of SH/SS bonds between protein molecules and facilitated the interaction of basic peptides and ß-subunits, leading to larger particle sizes of the soluble aggregates compared to the HHPH-treated samples. However, excessive aggregation in HPHH-treated aggregates leads to decreased H0 and adsorbed protein content, and increased interfacial tension, negatively affecting the emulsification properties. Compared to the HPHH treatment, HHPH treatment at homogenization pressures of 20 to 100 MPa increases EAI and ESI by 5.81-29.6 % and 5.31-25.9 %, respectively. These findings provide a fundamental basis for soybean protein manufacturers to employ appropriate processing procedures aimed at improving emulsification properties.

The functionality of laccase- or peroxidase-treated potato flour: Role of interactions between protein and protein/starch.

Potato flour is used in bakery products, extruded products and snacks. However, it displays weaker gel strengths and thus the wholesome utility is curtailed significantly. To improve viscoelastic properties and stability of potato gels, herein potato flour was treated with laccase and peroxidase to create a protein network structure leading to stable gels. The results revealed that the secondary structure of potato proteins altered upon the enzyme treatment. The gels of peroxidase-treated potato flour (PPF) and laccase-treated potato flour (LPF) displayed larger anti-shear ability, thermal stability and stronger three-dimensional network structure compared to the native potato gel. The PPF and LPF gels exhibited stronger viscoelastic properties and structural stability compared to peroxidase-treated potato protein and laccase-treated potato protein gels. The outcome serves as a theoretical basis to improve the properties of potato gels and to promote the designing and the development of novel potato flour based functional food.

Lycium barbarum polysaccharide attenuates myocardial injury in high-fat diet-fed mice through manipulating the gut microbiome and fecal metabolome.

High-fat diets (HFDs) can induce health problems including gut microbiota dysbiosis and cardiac dysfunction. In this study, we modulated the gut microbiota in mice to investigate whether Lycium barbarum polysaccharide (LBP), a potential prebiotic fiber, could alleviate HFD-induced myocardial injury. Mice fed a HFD were given LBP (HFPD group) by gavage once/day for 2 months. Left ventricular function and serum trimethylamine N-oxide were significantly improved in HFPD mice compared with HFD mice. HFD increased the abundances of Bifidobacterium, Lactobacillus, and Romboutsia, while LBP increased the abundances of Gordonibacter, Parabacteroides, and Anaerostipes. Fecal metabolic profiling revealed significant increases in metabolites involved in nicotinate, nicotinamide and purine metabolism pathways, as well as indole derivatives of tryptophan metabolites in the HFPD group. LBP reduced intestinal permeability and inflammatory cytokine levels, maintained a healthy intestinal microenvironment, and alleviated myocardial injury. Modulating the gut microbiota is a potential treatment for cardiovascular diseases.

Effect of industrial trans-fatty acids-enriched diet on gut microbiota of C57BL/6 mice.

PURPOSE: Previous studies have shown that industrially originated trans-fatty acids (iTFAs) are associated with several chronic diseases, but the underlying mechanisms remain unknown. Because gut microbiota play a critical role in human health, diet competent induced gut microbiota dysbiosis may contributing to disease pathogenesis. Therefore, the present study examined the impact of iTFA on gut microbiota, help understanding the underling mechanism of iTFA-associated chronic diseases. METHODS: Forty male 8-week-old mice were divided into 4 groups and randomly assigned to diets containing soybean oil (non-iTFA) or partially hydrogenated soybean oil (iTFA). The intervention groups were: (1) low soybean oil (LS); (2) high soybean oil (HS); (3) low partially hydrogenated oil (LH) and (4) high partially hydrogenated oil (HH). The gut microbiota profiles were determined by 16S rRNA gene sequencing. Physiological parameters and the inflammatory status of the small intestine and other tissues were analyzed. Short-chain fatty acid levels in feces were measured using gas chromatography. RESULTS: The intake of iTFA increased the abundance of well-documented 'harmful' bacteria, such as Proteobacteria and Desulfovibrionaceae (P < 0.05), whereas it decreased relative abundance of 'beneficial' bacteria, such as Bacteroidetes, Lachnospiraceae, Bacteroidales S24-7 (P < 0.05). Surprisingly, the intake of iTFA increased the abundance of the probiotic Lactobacillaceae (P < 0.05). Additionally, the intake of iTFA induced increase of inflammatory parameters, as well as a numerical decrease of fecal butyric acid and valeric acid. CONCLUSIONS: This study, to our knowledge, is the first to demonstrate that the consumption of iTFA resulted in a significant dysbiosis of gut microbiota, which may contribute to the development of chronic diseases associated with iTFA.