Effects of binary organic solvents and heating on lipid removal and the reduction of beany odour in Bambara groundnut (Vigna subterranean) flour

Influence of protein in low paste viscosities of Bambara groundnut flours from heat-treated Bambara groundnut seeds

Heat treatment of Bambara groundnut seeds has been reported to cause low paste viscosities in resulting flours. Structural changes in Bambara groundnut protein, due to heat treatment, causes the protein to encapsulate starch, making it unavailable to paste causing low paste viscosities. In this study, trypsin was used to hydrolyze proteins in the flour and the microstructure analysis confirmed the disappearance of aggregates. Flour microstructure analysis confirmed hydrolysis of protein from previously aggregated status and showed liberated individual starch granules. Following the treatment of flours by trypsin, Confocal laser scanning microscopy did not show a protein signal. Hydrolysing Bambara groundnut proteins significantly increased the flour paste viscosities (P < 0.05). The final viscosities for flours from 20 % moisture-conditioned and infrared heat-treated seeds for 5 min were 733.9 mPa s before protein hydrolysis and 2081.71 mPa s after protein hydrolysis. The gelatinization temperature (81 °C) did not show a significant change following protein hydrolysis. Sodium dodecyl-sulphate polyacrylamide gel electrophoresis band intensity increased indicative of disulfide bonding and protein polymerisation when microwave and infrared heat treatment were combined. There were changes in Bambara groundnut protein secondary structures such as an increase of 57 % in β-sheet along with a 60 % reduction in the α-helix as shown by the Fourier-transform infrared spectroscopy. The changes in secondary structure of Bambara groundnut protein were caused by microwave and infrared heating. Heat treatment of Bambara groundnut seeds is partly responsible for the reduction in paste viscosities of their flours.

Application of legumes in plant-based milk alternatives: a review of limitations and solutions

In recent years, a global shift has been observed toward reducing the consumption of animal-derived foods in favor of healthier and more sustainable dietary choices. This has led to a steady growth in the market for plant-based milk alternatives (PBMAs). Projections suggest that this market will reach a value of USD 69.8 billion by 2030. Legumes, being traditional and nutritious ingredients for PMBAs, are rich in proteins, dietary fibers, and other nutrients, with potential health benefits such as anticancer and cardiovascular disease prevention. In this review, the application of 12 legumes in plant-based milk alternatives was thoroughly discussed for the first time. However, compared to milk, processing of legume-based beverages can lead to deficiencies such as nutritional imbalance, off-flavor, and emulsion stratification. Considering the potential and challenges associated with legume-based beverages, this review aims to provide a scientific comparison between legume-based beverages and cow's milk in terms of nutritional quality, organoleptic attributes and stability, and to summarize ways to improve the deficiencies of legume-based beverages in terms of raw materials and processing method improvements. In conclusion, the legume-based beverage industry will be better enhanced and developed by improving the issues.

Volatile Compound, Physicochemical, and Antioxidant Properties of Beany Flavor-Removed Soy Protein Isolate Hydrolyzates Obtained from Combined High Temperature Pre-Treatment and Enzymatic Hydrolysis

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G′, G″) of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.