Green tea catechins are the major components of the antioxidants contained in tea leaves, and show a stronger antioxidative activity than natural tocopherols and polyphenols. Green tea catechins (Sankatol^TM, Taiyo Kagaku Co., Ltd.) used as antioxidants in lard, fish oil and oil-fried noodles exhibited an efficient antioxidative effect. Also, Sankatol^TM prevented the peroxidation and bad taste of milk fat caused by photooxidation. They have been used as antioxidants in foods, oils and beverages. The antidiscoloring activity of the individual catechins on β-carotene was attributed to the hydroxyl group at the 5'-position of the B ring of the catechin skeleton which has an important antioxidative activity. Recently, it has been reported the accelerated antioxidant effect of the catechin combined metal ions and the superior antioxidative activity of planar catechins compared to native catechins. As a result of these studies, the potential range of catechin applications was significantly broadened.

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Rosemary (Rosemarinus officinalis) is a kind of well-known herbs and its extract is used as an antioxidant widely. Some components in the extract, such as rosmarinic acid, carnosol, carnosic acid and rosmanol have stronger antioxidative activity than vitamin E and BHT, (2, 6-di-tert-butyl-4-hydroxytoluene). This report introduces the antioxidative components and the effect of rosemary extract and novel use in food. The causes of food degradation are influenced by internal and external factors. The internal factors are the contents in food such as oil or enzymes, and the external factors are the environment of the food. The prevention of oil degradation and enzyme inhibition were observed when rosemary extract was added in food, and the degradation by light and heat were also repressed by rosemary extract.

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Lipase catalyzed trans-esterification is one of the excellent methods to obtain functional foods oils. Nevertheless, this techniques has been put into practice only in limited areas. It is necessary to design the reaction system as simply as possible to develop it for versatile use such as hydrogenation, chemical esterification and fractionation.
For the immobilization processing, other substances are required as a carrier, by which the specific activity of the enzyme is inevitably decreased. Thus, we investigated the trans-esterification reaction in consideration of the point that a compact reaction system can be designed by using powdered lipase.
Optimal reaction temperature was higher for lipase powder with lower water content. The optimal reaction temperature of the lipase powder was 85°C and its activity was 20% of the activity of the optimal temperature, even at the higher temperature of 130°C. The half-life of the lipase powder activity was determined to be 380 hour by repeated reaction at 80°C.
The method developed by us has been put into practice in the industrial production of several kinds of functional food oils such as healthy oil consisting of Medium-chain Fatty acids and Phytosterol ester.

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