Chemical components, palatability, antioxidant activity and antimutagenicity of oncom miso using a mixture of fermented soybeans and okara with Neurospora intermedia.

The enzyme activities of Aspergillus oryzae on koji (malted rice) and Neurospora intermedia on S-oncom and O-oncom (fermented soybeans and okara with N. intermedia, respectively) were compared. The major enzymes of N. intermedia were different from those of A. oryzae, and the enzyme activities of O-oncom were extremely higher than those of S-oncom. S5-Miso, S10-miso and S9O1-miso replacing 50% or 100% of steamed soybeans with S-oncom or a 9 : 1 mixture of S-oncom and O-oncom, respectively, were prepared to supplement the enzyme action of koji. The chemical components of those miso were almost the same as those of soybean-miso (C-miso). The miso soups prepared with S5-miso, S10-miso and S9O1-miso were all considered to be more palatable and pleasant-tasting than the soup prepared with C-miso, and their flavor was preferred in the same degree as that of T5-miso using 50% tempeh, the soybeans fermented with Rhizopus oligosporus. Scavenging activities of DPPH and O2- and antimutagenicity of the 70% ethanol extract from those miso were higher than those of hot-water extract, and the activities of S9O1-miso were the highest. The isoflavone-aglycons and brownish color of S9O1-miso were higher than those of C-miso. The higher contents of isoflavone-aglycons and melanoidines of S9O1-miso might contribute to their higher antioxidant activity and antimutagenicity. From these results, S9O1-miso has potential as a healthier alternative to C-miso in terms of taste and health benefits.

In vivo antioxidant activity of methanol extract from quinoa fermented with Rhizopus oligosporus.

Previously, this author reported that the fermentation of quinoa with Rhizopus oligosporeus increased antioxidant activity, and the antioxidant activity of the 80% methanol extract of the fermented quinoa (Q-tempeh) was higher than the other extracts with n-hexane and water in vitro. In this paper, to clarify a beneficial effect of the fermentation of quinoa with R. oligosporus, the antioxidant activity of 80% methanol extract of Q-tempeh was investigated in rats ex vivo and in vivo. In the ex vivo experiment, the 80% methanol extract from Q-tempeh increased both activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver, and accelerated the production of 12-hydroxyeicosatetraenoic acid (12-HETE) in the lung. In rats fed vitamin E-free diets with 80% methanol extract of Q-tempeh, the alpha-tocopherol concentration, thiobarbituric acid-reactive substance (TBARS) value, and activities of GSH-Px and SOD in serum showed a similar concentration to those of the control rats fed a vitamin E-supplemented diet. However, the hepatic GSH-Px and SOD activities were higher than those in the control rats. On the other hand, in rats fed a vitamin E-free diet with the 80% methanol extract of quinoa, the serum alpha-tocopherol level was lower, and both TBARS values of serum and liver were higher than those in the control rats. From these results, the 80% methanol extract of Q-tempeh was inferred to be an active superoxide scavenger and peroxide reducer in vivo.

Saccharification of Okara fiber by plant dietary fiber hydrolases.

In this paper, the saccharification process of okara fiber with pectinase, xylanase and cellulase was investigated as a preliminary attempt to effectively utilize okara fiber. The solubilization of okara fiber was raised in proportion to the number of enzymes used; that is, by a single enzyme, two enzymes and three enzymes, in that order. The saccharification of okara fiber was much more completed by a combination of pectinase, xylanase and cellulase than by using individual preparations. This multi-enzyme system liberated sugars equivalent to 80% of the original okara fiber by weight. Moreover the structure of okara fiber gradually disintegrated by hydrolytic reactions with pectinase, xylanase and cellulase in turns. These results suggest that the saccharification of okara fiber progresses by the cooperative action of pectinase, xylanase and cellulase.

Low-salt O-miso produced from Koji fermentation of oncom improves redox state and cholesterolemia in rats more than low-salt soybean-miso.

The author prepared low-salt miso by koji fermentation using soy-oncom and okara-oncom (9:1), at which time soybeans and okara were fermented with Neurospora intermedia (oncom miso, i.e. O-miso). Its usefulness as a seasoning, as well as high antioxidative activity in vitro and antimutagenicity have already been presented. In this study, the antioxidative activity of O-miso in vivo, as well as serum cholesterol-lowering action, were investigated concerning contribution to health. In rats fed O-miso, the serum alpha-tocopherol level and isoflavone-aglycone-intake were higher than in rats fed low-salt soybean miso (S-miso). The activities of serum GSH-Px and hepatic catalase were also higher in rats fed O-miso than in rats fed S-miso, while the TBARS values were lower in both the serum and livers of rats fed O-miso. Furthermore, O-miso intake suppressed a rise in serum cholesterol level and increased fecal bile acid excretion. Such a cholesterol-lowering action of O-miso may be attributable to the micelle-breaking or evacuant effects of indigestible proteinous residues and the antioxidative activity of isoflavone-aglycones. O-miso seems to be more beneficial to health than S-miso in view of these aspects.

Hydrophilic antimutagens in fermented defatted soybeans with Neurospora intermedia (D-oncom).

The author has previously reported on the higher antioxidative activity in vivo of defatted soybean oncom (D-oncom), fermented defatted soybeans with Neurospora intermedia, in comparison with that of defatted soybeans (DSB). In this paper, the hydrophilic antimutagenicity of D-oncom against N-nitrosodimethylamine (NDMA) was investigated. Water-extract of D-oncom had a stronger antimutagenicity than that of DSB. The main antimutagenic fraction of D-oncom was anionic, and stable against heating at 37 degrees C. Its antimutagenicity was about one sixth of that of ascorbic acid. Actually the fraction scavenged superoxide anions. Therefore, the antimutagenicity of D-oncom against NDMA might be involved in the reduction of oxidative stress by scavenging superoxide anions. Nonetheless the main antimutagenic fraction was not polyphenol, peptide nor nucleotide, its molecular weight being distributed about 5000-12,500.