Isoflavones found in soybeans are present as glycosides and aglycones, which differ according to their chemical structure. The absorption rate and bioavailability of aglycones are greater than those of glycosides. It is known that aglycone isoflavones in soybean was converted from glycoside isoflavones by activating of endogenous β-glucosidase under drying (40~60℃) conditions after soaking. In this study, we compared and analyzed the proximate composition and isoflavone contents of soybean powders prepared under dried after soaking were analyzed. In the comparison of the proximate compositions, the moisture contents of white soybean powder dried after soaking (WSPDS) and black soybean powder dried after soaking (BSPDS) were decreased as compared with those of the control white soybean powder (CWSP) and control black soybean powder (CBSP). Whereas the contents of other proximate compositions were increased. The aglycone isoflavone contents were higher in WSPDS than in CWSP. Whereas the aglycone isoflavone contents of BSPDS had a similar content those of CBSP because of the component characteristics of black soybean. In conclusion, we believe that it is appropriate to identify and utilize the component characteristics of soybean varieties in order to induce an increase in the functional component content of soybeans under drying conditions after soaking.

We reported a new white soybean cyst nematode, Heterodera sojae in 2016. This species is closely related to H. glycineswhich has the same host plant. Morphological observations of the cyst, female, male and second-stage juveniles indicatedthat this species is differed from those of H. glycines. Cysts of H. sojae appeared more round, shining and darker thanthat of H. glycines. The distribution of this new cyst nematode in soybean field in Korea is unknown yet. In 2016, 270soil samples were collected from soybean fields and examined the existence of H. glycines and H. sojae. Total of 111samples (41.1%) contained cysts. Among them 77% were H. glycines and 23% were H. sojae. Our results suggest thatextensive researches are required for white soybean cyst nematode.

Insects are attracting the attention of alternative sources of protein. In order to produce high quality insects, studieson the development of safe and nutritious feed sources are needed. Given the cost of rearing insects, agricultural andindustrial by-products were good materials of insect feed. In the current study, Citrus unshiu peel (CP), soybean curdcake (SCC), soybean oil meal (SOM), and brewers dried grain (BDG) were investigated for their effects on larval growthand development of Protaetia brevitarsis. Interestingly, larvae fed on 10% SCC increased their weight by 3.5 times. Forthe larval period, they were significantly shorter than the control. Furthermore, minerals and amino acids were recordedto be high in them. The heavy metals were not detected in any of the investigated groups. These findings provided ascientific basis for the utilization of soybean curd cake as a nutritional feed source to promote larval growth and producequality insects.

In order to investigate the utilization of the Omija (Schizandra chinensis Baillon) extract as a natural coagulant for manufacturing soybean curd, the quality characteristics of white (Baktae) and black (Seoritae) soybean curds, coagulated by the Omija extract or MgCl2, were evaluated. Crude protein (6.14±0.30 and 6.25±0.18%, respectively) and crude lipid (10.86±1.74 and 11.29±1.69%, respectively) contents of white and black soybean curds coagulated using the Omija extract were higher than those coagulated using MgCl2. Black soybean curds coagulated using the Omija extract showed higher L, a, and b values than those using MgCl2. The most abundant amino acid in white and black soybean curds coagulated using the Omija extract was arginine (3.74 and 3.71 mg/100 g, dry basis, respectively). The amounts of Ca, K, Mg, and Na were the highest in both soybean curds prepared with the Omija extract. The sensory evaluation (color, flavor, taste, texture, and overall preference) showed that white and black soybean curds coagulated using the Omija extract were more preferred than those produced using MgCl2. The results suggested that using the Omija extract as a natural coagulant agent could improve the quality and sensory characteristics of soybean curds.