Effect of conventional and microwave heating treatment on antioxidant activity of quinoa protein after simulated gastrointestinal digestion

Effect of α-tocopherol, soybean oil, and glyceryl monostearate oleogel on gel properties and the in-vitro digestion of low-salt silver carp (Hypophthalmichthys molitrix) surimi

To improve nutritional health, a low-salt (0.5 %) silver carp (Hypophthalmichthys molitrix) surimi gel with α-tocopherol, soybean oil, and glyceryl monostearate oleogel was fabricated and evaluated for textural qualities, lipid oxidation, and in-vitro digestion analysis. Based on the texture profile analysis, gel strength, water holding capacity (WHC), rheological, protein secondary structure, and microstructural examination, 5 % oleogel addition to low-salt surimi exhibited similar physicochemical properties to regular-salt surimi gels. By crosslinking myosin and filling protein network voids, the oleogel increased surimi gel density. Increasing oleogel content improved the physicochemical qualities of heat-induced surimi, causing protein aggregation during digestion and reducing digestibility. The presence of oleogel altered protein secondary structure, reducing α-helix content and increasing β-sheet and other structures, enhancing WHC and gel strength of low salt surimi. Adding oleogel improved the antioxidant activity of digestive solutions. This study will help understand myosin-oleogel interaction and the development of sustainable and nutritious surimi-based foods.

Metabolomics Analysis of Different Quinoa Cultivars Based on UPLC-ZenoTOF-MS/MS and Investigation into Their Antioxidant Characteristics

In recent years, quinoa, as a nutritious and sustainable food material, has gained increasing popularity worldwide. To investigate the diversity of nutritional characteristics among different quinoa cultivars and explore their potential health benefits, metabolites of five quinoa cultivars (QL-1, SJ-1, SJ-2, KL-1 and KL-2) were compared by non-targeted metabolomics analysis based on UPLC-ZenoTOF-MS/MS in this study. A total of 248 metabolites across 13 categories were identified. Although the metabolite compositions were generally similar among the different quinoa cultivars, significant variations existed in their respective metabolite contents. Among the identified metabolites, amino acids/peptides, nucleosides, saponins and phenolic acids were the most abundant. Notably, SJ-1 exhibited the most distinct metabolite profile when compared to the other cultivars. Amino acids/peptides and nucleosides were found to be crucial factors contributing to the unique metabolite profile of SJ-1. Collectively, these aforementioned metabolites accounted for a substantial 60% of the total metabolites observed in each quinoa variety. Additionally, a correlation between the DPPH radical scavenging activity and the free phenolic content of quinoa was observed. Variations in phenolic content resulted in different antioxidant capacities among the quinoa cultivars, and SJ-1 exhibited lower phenolic levels and weaker antioxidant activity than the others. These results can provide important information for the development of quinoa resources.

Biomacromolecule assembly of soy glycinin-potato starch complexes: Focus on structure, function, and applications

The effect of the cross-linking mechanism and functional properties of soy glycinin (11S)-potato starch (PS) complexes was investigated in this study. The results showed that the binding effecting and spatial network structure of 11S-PS complexes via heated-induced cross-linking were adjusted by biopolymer ratios. In particular, 11S-PS complexes with the biopolymer ratios of 2:15, had a strongest intermolecular interaction through hydrogen bonds and hydrophobic force. Moreover, 11S-PS complexes at the biopolymer ratios of 2:15 exhibited a finer three-dimensional network structure, which was used as film-forming solution to enhance the barrier performance and mitigate the exposure to the environment. In addition, the 11S-PS complexes coating was effective in moderating the loss of nutrients, thereby extending their storage life in truss tomato preservation experiments. This study provides helpful to insights into the cross-linking mechanism of the 11S-PS complexes and the potential application of food-grade biopolymer composite coatings in food preservation.

Modifying quinoa protein for enhanced functional properties and digestibility: A review

Quinoa (Chenopodium quinoa Willd.) is a pseudocereal plant that originally came from South America. The trend of consuming quinoa is propelled by its well‒balanced amino acid profile compared to that of other plants. In addition, its gluten‒free nature makes quinoa a promising diet option for celiac disease patients. Protein accounts for approximately 17% of the quinoa seed composition and quinoa protein possesses excellent quality. Quinoa protein is mainly composed of 11S globulins (37%) and 2S albumins (35%), both of which are stabilized by disulfide bonds. To date, the alkaline extraction method is the most commonly used method to extract quinoa protein. The functional properties and digestibility of quinoa protein can be improved with the help of various modification methods, and as a result, the application of quinoa protein will be extended. In this review, the extraction method, modification of functional properties and digestibility of quinoa protein are thoroughly discussed, providing insights into the application of quinoa protein in plant‒based foods.