The modified ferric thiocyanate method (PV* method) previously reported by the authors was evaluated for use in the determination of peroxide values (PV) of commercial edible oils in order to ascertain and improve the speed and precision of the PV* method. The PV* method has been confirmed as a simple and rapid determination of PV for very small amounts of sample (0.01-0.15g oil), compared with the PV method (JOCS acetic acid-isooctane method, sampling weight 0.5-5.0g oil). The PV* measurements are capable of nearly the same precision as PV measurements. This novel method was applied to evaluate oxidative stability in the autoxidation of several commercial edible oils and emulsified liquid type dressings. The results showed that the oxidative stability of oils increased in the following order : tuna fish oil<perilla oil<rice bran oilmiddle chain fatty acid type oil<soybean oil∼corn oil<roasted sesame oil<diacylglycerol oil.

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This study was conducted to assess the effects of trehalose on the morphology and the measurement of viability of cells treated with acids, cigarette smoke extract (CSE) and phenol (a CSE constituent) using in vitro cultured human cells. While cells treated with 0.2% (w/v) ascorbic acid were damaged, cells treated with 0.5% (w/v) trehalose, preserved their shapes even in the presence of an identical concentration of ascorbic acid. In addition, the mean values of cell viability after treatment with 0.2% (w/v) citric acid, one-fourth diluted CSE, and 0.2% (w/v) phenol, were 8%, 37% and 50%, respectively. Under the same conditions, when 1%, 2.5% and 2.5% of trehalose were added to the cell culture, the mean values of cell viability increased to 54%, 55% and 81%, respectively. These results suggest that trehalose protects cells from damage induced by stimulants in the oral cavity, indicating that trehalose is suitable for the formulations of products such as throat candies.

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We investigated the effect of lactic acid-fermented soymilk, in which a portion of soymilk was replaced with okara, on plasma and liver lipid concentrations in rats. Male Sprague-Dawley rats were fed a high-cholesterol diet (control diet) or test diet in which 20% of the diets were replaced by soymilk, fermented soymilk or a fermented soymilk/okara mixture. Fermented soymilk/okara was expected to be smoother in taste because finely powdered okara was used, instead of intact soybeans. Only rats fed a fermented soymilk/okara diet showed a significantly and continuously lower level of plasma total cholesterol. The hepatic triglyceride concentration in the rats fed the soymilk and fermented soymilk/okara diets showed significantly lower levels than rats fed the control diet. These results suggest that a mixture of fermented soymilk and okara has a significant advantage of the beneficial effects of okara, and shows greater plasma cholesterol-lowering and hepatic lipid-lowering effects than fermented soymilk alone. Therefore, fermented soymilk/okara is available as a functional food for prevention of hyperlipidemia. In addition, okara, which has been discarded as industrial waste, could be efficiently used as fermented soy food.

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[in Japanese]

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