The Effects of Fungal Stress on the Antioxidant Contents of Black Soybeans under Germination

Abstract

Black soybeans were germinated with or without Rhizopus oligosporus for 3 days. The samples collected from each day were freeze-dried and extracted with chloroform-methanol-water mixture to simultaneously obtain organic phase (lipophilic extract) and aqueous phase (hydrophilic extract). In the lipophilic extract, α-, γ-, and δ-tocopherol were drastically decreased by 51%, 97%, and 88%, respectively, after 3 day germination under stress. On the other hand, the lipid peroxide concentration was increased in the fungi stressed, germinating beans from day 2 onward, while it was continually decreased in the nonstressed germinating counterpart. The change of antioxidant capacity (ORACoil value) was correlated to the changes of tocopherols and lipid peroxide concentrations. In nonstressed germinatng beans, ORACoil value dropped by 38% after 3 days, while in the fungi-stressed germinating beans, ORACoil was decreased by 80%. In hydrophilic extract, the antioxidant activity, measured by ORAChydro assay, is about 80 times higher than the ORACoil values, but there is no significant change before and after germination (either with or without stress). The total phenolic content in the hydrophilic extract increased only slightly by 9% in germinated beans and 15% in fungus-stress germinated samples, respectively. The advantage of stress germination of soybeans in enriching phytoalexins is traded off by loss of tocopherols.

Influence of elicitation with H2O2on phenolics content, antioxidant potential and nutritional quality ofLens culinarissprouts

“…Free radical scavenging properties were improved by elicitation with natural elicitors, such as fish protein hydrolysates, lactoferrin and oregano extract. Also, Feng and co‐workers obtained a significant elevation in the antioxidant potential of black soybean sprouts by treatment with components of fungal cell walls. There are also some reports concerning the elevation of the nutraceutical potential of edible sprouts by elicitation .…”

Effects of Synergistic Inhibition on α-glucosidase by Phytoalexins in Soybeans

“…Phytoalexins include isoflavones which are induced by plant defense mechanisms against soil pathogens, such as bacteria and fungi [6]. Phytoalexins are also produced when soybeans are exposed to various stresses, such as microbes, ultraviolet light, and other physical attacks [7]. Soybean-derived…”

Nutritional and antioxidant potential of a desert underutilized legume – tepary bean (Phaseolus acutifolius). Optimization of germination bioprocess

“…The germination bioprocess enhances the nutritional quality of seeds by expanding the levels of available carbohydrates, free amino acids, dietary fiber, and other components. Also improving the functionality of the grains due to the subsequent increments in antioxidant capacity and related bioactive compounds (Khattak et al, 2008;Cevallos-Casals & Cisneros-Zevallos, 2010;Feng et al, 2010;Shi et al, 2010;Wu et al, 2011). Polyphenols is one of the manly groups of antioxidant compounds that increase during germination; they have the capacity to reduce the oxidative damage of the cell membranes ocasioned by reactive free radicals, prevent the oxidative damage in foods as well as in the human body (López-Amorós et al, 2006;Fernandez-Drozco et al, 2009).…”