Molecular docking and dynamic simulation studies of isoflavones inhibiting Lox-2 activity for reducing beany flavor in soybean seeds

Low-lipoxygenase soybean cultivars are highly desirable because lower lipoxygenase content in soybean seeds leads to better quality soybean-based products and oils that are free from off-flavor or beany flavor. The expression of the Lox-2 gene is mainly responsible for this flavor. Over the years, natural antioxidants have been tested biochemically to inhibit Lox-2 activity, but in-silico studies are still lacking. To investigate the structural basis of inhibition, site-specific docking, as well as molecular dynamics (MD) simulations, were performed. Molecular docking analysis revealed that daidzein and genistein could be effective Lox2 receptor inhibitors. Furthermore, docked complexes were subjected to 100 ns MD simulation studies to analyze the structural conformations and stability of the complex. The analysis demonstrated that daidzein formed a more stable complex with the Lox-2 receptor and showed a higher H-bond propensity with the Asp775 residue. We discovered that the initial conformation of Lox2-daidzein complex changed to a more stable conformation at the beginning of the MD simulation and remained stable until the end with minor fluctuations. Furthermore, our analysis suggested that daidzein acts as a potential Lox-2 inhibitor and is a better candidate compared to genistein, which could be used to solve the beany flavor problem in soybean.Communicated by Ramaswamy H. Sarma.

Control of Beany Flavor from Soybean Protein Raw Material in Plant-Based Meat Analog Processing

The development of plant-based meat analogs is currently hindered by the beany flavor generated by raw soybean protein and extrusion processing. Wide concern has led to extensive research on the generation and control of this unwanted flavor, as an understanding of its formation in raw protein and extrusion processing and methods through which to control its retention and release are of great significance for obtaining ideal flavor and maximizing food quality. This study examines the formation of beany flavor during extrusion processing as well as the influence of interaction between soybean protein and beany flavor compounds on the retention and release of the undesirable flavor. This paper discusses ways to maximize control over the formation of beany flavor during the drying and storage of raw materials and methods to reduce beany flavor in products by adjusting extrusion parameters. The degree of interaction between soybean protein and beany compounds was found to be dependent on conditions such as heat treatment and ultrasonic treatment. Finally, future research directions are proposed and prospected. This paper thus provides a reference for the control of beany flavor during the processing, storage, and extrusion of soybean raw materials used in the fast-growing plant-based meat analog industry.

Effect of Revtech thermal processing on volatile organic compounds and chemical characteristics of split yellow pea (Pisum sativum L.) flour

Yellow pea (Pisumsativum L.) is an economically rich source of nutrients with health-promoting effects. However, the consumption of pea ingredients is minimal due to their off-flavor characteristics. The present study investigated the effect of Revtech heat treatment on the chemical profile and volatile compounds in split yellow pea flour. Revtech treatment (RT) was applied at 140°C with a residence time of 4 min in dry condition (RT 0%) and in the presence of 10% steam (RT 10%). Both thermal treatments resulted in a significant reduction (p < 0.05) in lipoxygenase activity and the concentration of key beany-related odors such as heptanal, (E)-2-heptenal, 1-octen-3-ol, octanal, and (E)-2-octenal. In addition, RT 10% resulted in a significant reduction in pentanal, 1-penten-3-ol, hexanal, and 1-hexanol compared to untreated flour. The content of known precursors of lipoxygenase such as linoleic and linolenic acids was found in higher concentrations in heat-treated flours, indicating the efficacy of Revtech technology in minimizing the degradation of polyunsaturated fatty acids. No significant changes in the amino acid composition or the 29 selected phenolic compounds in pea flours were observed with Revtech processing except for two compounds, caffeic acid and gallocatechin, which were found at higher concentrations in RT 0%. PRACTICAL APPLICATION: Thermal processing of split yellow pea flours at 140°C using Revtech technology successfully decreased the concentrations of volatile compounds responsible for beany off-flavor while improving the nutritional quality of studied yellow pea flours. These results provide valuable information to the food industry for developing novel pulse-based products with enhanced sensory characteristics.

β-Cyclodextrin-Mediated Beany Flavor Masking and Textural Modification of an Isolated Soy Protein-Based Yuba Film

The application of β-cyclodextrin (CD) to remove unattractive volatile compounds has been applied in various food products. This study investigated the effect of CD concentration (1–4%) on the beany flavor masking and textural modification of yuba film prepared by isolated soy protein (ISP) in the presence of (+CD), or after removing, the flavor-entrapped CD (−CD). Based on gas chromatography–mass spectrometry (GC–MS), the addition of CD caused a decrease in 1-octen-3-ol, benzaldehyde, hexanal, and 2-heptanone, which are characterized as the major beany flavor compounds. Regardless of presence or removal, the use of CD was effective in reducing beany flavor in yuba film. Scanning electron microscopy (SEM) observation indicated that the CD present in yuba film was distributed on the lower surface and matrices of the films. In yuba film containing 4% CD, the CD crystals were concentrated on both the upper and lower surfaces of the film. The textural properties of the yuba film were affected by the presence or removal of CD, and better puncture strength was obtained when yuba was made after removing the CD. Therefore, this study indicates that the addition of CD was a good approach to mask the beany flavor of soy protein-based products, and textural properties could be improved by removing CD from the product formulation.

Optimization of soymilk, mango nectar and sucrose solution mixes for better quality of soymilk based beverage

BACKGROUND

Soy milk-based beverages play an important role as a healthy food alternative for human consumption. However, the &lsquo;beany&rsquo; flavor and chalky mouth feel of soy milk often makes it unpalatable to consumers. The objective of the present study is to optimize a blend of soy milk, mango nectar and sucrose solution for the best quality soy milk-based beverage.

METHODS

This study was designed to develop a soy milk blended beverage, with mango nectar and sucrose solutions, with the best physicochemical and sensory properties. Fourteen combinations of formulations were determined by D-optimal mixture simplex lattice design, by using Design expert. The blended beverages were prepared by mixing the three basic ingredients with the range of 60&minus;100% soy milk, 0&ndash;25% mango nectar and 0&ndash;15% sucrose solution. The prepared blended beverage was analyzed for selected physicochemical and sensory properties. The statistical significance of the terms in the regression equations were examined by Analysis of Variance (ANOVA) for each response and the significance test level was set at 5% (p < 0.05).

RESULTS

The results showed that, as the proportion of mango nectar and sucrose solution increased, total color change, total soluble solid, gross energy, titratable acidity, and beta-carotene contents increased but with a decrease in moisture , ash, protein, ether extract, minerals and phytic acid contents was observed. Fi- nally, numerical optimization determined that 81% soy milk, 16% Mango nectar and 3% sugar solution will give by a soy milk blended beverage with the best physicochemical and sensory properties, with a desirability of 0.564.

CONCLUSIONS

Blending soy milk with fruit juice such as mango is beneficial, as it improves sensory as well as selected nutritional parameters.

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.