การพัฒนาส่วนผสมอาหารจากสารประกอบพันธะเชื่อมเชิงหน้าที่ที่มีฤทธิ์ทางชีวภาพจากถั่วเหลืองและถั่วเหลืองผิวดำ

Abstract

This study was conducted to investigate the beneficial bioactive functional conjugated compounds from soybean and black soybean. Soybean and black soybean were used to produce isoflavone aglycone by five lactic acid bacteria (Lactobacillus casei subsp. rhamnosus TISTR047, Lactobacillus bulgaricus TISTR451, Lactobacillus plantarum TISTR43, Streptococcus thermophilus TISTR894 and Bacillus subtilis TISTR001). It was found L.casei subsp. rhamnosus TISTR047, L. bulgaricus TISTR451 and L. plantarum TISTR543 can convert of the glucoside (daidzin, glycitin, genistin) to aglycone (daidzein, glycitein, genistein) in both soybean and black soybean higher than S. thermophilus TISTR894 and B. subtilis TISTR001. The highest activities during fermentation in soybean and black soybean was Lcasei subsp. rhamnosus TISTR047. Then, optimal fermentation condition was continually investigated by L.casei subsp. rhamnosus TISTR047. The volume of L.casei subsp. rhamnosus TISTR047, fermentation temperature and time were also varied. It was found that, the optimal condition of soybean fermentation was 13.50% at 38.51'C for 7 days. On the other hand, the optimal condition of black soybean fermentation was 13.49% at 38.49*C for 8 days. The isoflavone content and antioxidant activities (ABTS and FRAP) from soybean extract was higher than black soybean extract. On the other hand, soybean and black soybean were also used to produce protein hydrolysate by enzyme technology using protease. The molecular weight of soybean and black soybean hydrolysate had 10-15 kDa and 10-20 kDa, respectively with suitable enzyme level of 0.75% for 5 hours 18 minutes. Soybean hydrolysate had a higher degree of hydrolysis and total amino acid content than black soybean hydrolysate. Moreover, soybean hydrolysate and soybean extract were used as materials to generate the bioactive functional conjugated compounds. It was envishided that optimal condition of conjugated compounds was pH 8 and could be generated molecular weight of conjugated compounds approximately 50-70 kDa. Moreover, The conjugated compounds had foaming properties, emulsion properties, pH stability at pH 7-9 and thermal stability at 50C for 6 hours which those properties could be applied as food ingredients.