β-GLUCOSIDASE ACTIVITY OF SOYBEAN (GLYCINE MAX) EMBRYONIC AXIS GERMINATED IN THE PRESENCE OR ABSENCE OF LIGHT

Legume Seeds as an Important Component of Human Diet

Legumes are an important source of nutrients (proteins, carbohydrates, water soluble vitamins, minerals) for human nutrition [...].

Multistep Optimization of β-Glucosidase Extraction from Germinated Soybeans (Glycine max L. Merril) and Recovery of Isoflavone Aglycones

Epicotyls from germinated soybeans (EGS) have great potential as sources of endogenous β-glucosidase. Furthermore, this enzyme may improve the conversion of isoflavones into their corresponding aglycones. β-Glucosidase may also increase the release of aglycones from the cell wall of the plant materials. Therefore, the aim of this work was to optimize both the extraction of β-glucosidase from EGS and to further examine its application in defatted soybean cotyledon to improve the recovery of aglycones, which were evaluated by ultra-high performance liquid chromatography (UHPLC). A multistep optimization was carried out and the effects of temperature and pH were investigated by applying a central composite design. The linear effect of pH and the quadratic effect of pH and temperature were significant for the extraction of β-glucosidase and recovery aglycones, respectively. Optimum extraction of β-glucosidase from EGS occurred at 30 °C and pH 5.0. Furthermore, the maximum recovery of aglycones (98.7%), which occurred at 35 °C and pH 7.0⁻7.6 during 144 h of germination, increased 8.5 times with respect to the lowest concentration. The higher bioaccessibility of aglycones when compared with their conjugated counterparts is well substantiated. Therefore, the data provided in this contribution may be useful for enhancing the benefits of soybean, their products, and/or their processing by-products.

Profile of the contents of different forms of soybean isoflavones and the effect of germination time on these compounds and the physical parameters in soybean sprouts

The aim of this study was to evaluate the profile of the contents of different forms of soybean isoflavones and the effect of germination time on these compounds and the physical parameters in BRS 284 soybean sprouts. Soybean seeds were germinated for 168 h, and the sprouts were collected every 24 h. The physical parameters and contents of different forms of isoflavones of the seeds and soybean sprouts were evaluated, and the data were subjected to regression analysis. The soybean seeds contained 26.0% β-glucosides, 72.9% malonylglucosides and 1.2% aglycones. The yield of soybean sprouts was 632.4%. The effect of germination time was quadratic on the length, moisture and on the daidzin, genistin and genistein content; linear on the fresh weight and on the malonyldaidzin content. The dry matter and malonylglycitin content was constant, and glycitin and glycitein were not detected in the soybean sprouts.

Isoflavones of the soybean components and the effect of germination time in the cotyledons and embryonic axis

The aim of this study was to evaluate the content of different forms of isoflavones of BRS 284 soybean components and the effect of germination time in the cotyledons, radicle, and hypocotyl. Seeds were germinated until 168 h at 35 °C and collected each 24 h. The isoflavone content was determined by ultraperformance liquid chromatography, and the data were subjected to regression analysis. In cotyledons, germination time had a quadratic effect on daidzin and genistin contents and a linear effect on malonyldaidzin and malonylgenistin contents. In radicles, germination time had a quadratic effect on daidzin, glycitin, malonylgenistin, and malonylglycitin contents in addition to a linear effect on malonyldaidzin content. In hypocotyls, germination time showed a cubic effect on daidzin and genistin contents, a quadratic effect on malonyldaidzin, malonylgenistin, and malonylglycitin contents, and a linear effect on genistein content; glycitin, daidzein and glycitein were detected in a few germination times.