'Hokowase' strawberries (Fragaria ananassa DuCH) were treated with 100% CO₂ at 25°C for 0, 3, 6, 12, 18 or 24 hr. The flesh firmness of fruit increased for all CO₂ treatments tested. The 6 hours treatment was the most suitable duration for maintaining quality of the fruit, because a long time treatment caused severe browning of sepal and an off-flavor of the fruit. The fruit which was stored 0, 24 or 48 hr. after harvest were treated with 100% CO₂ for 6 hr. The delayed treatment, 24 hr. and 48 hr. after harvest, was more effective for increasing firmness and prevention of decay than non-treatment. The fruit were treated with 100% CO₂ or N₂ for 24 hr. CO₂ treatment resulted in firmer fruit and a decrease of the ratio of water soluble pectin content and an increase of hexametaphosphate soluble pectin, while N₂ treatment did not affect texture or pectin substances.

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Effect of dietary fungi on immunoglobulin G (IgG) concentration of serum and B lymphocytes of intestinal mucosa were investigated in rats sensitized subcutaneously by antigen. Experimental diets containing freeze-dried powders of Enokitake and Shiitake at 5% or 10% level were given to five week-old Sprague-Dawley male rats for 3 weeks. The experiments were performed twice. A significant decrease of body weight gain and a significant increase of small intestininal weight were shown in the 5% Enokitake group compared with the 5% cellulose and Shiitake groups. The IgG production in serum of rats was enhanced by Shiitake powder administration, but the effect of Enokitake powder was unclear because of the decreased body weight. No definite response was observed in the proportion of κ-light chain presenting lymphocytes in all the intestinal mucosa among the test groups. But, the proportion of IgA presenting lymphocytes in colonic mucosa tended to be higher than those in the small intestinal and cecal mucosa, suggesting different responses at the intestine portion.

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The present study investigated the changes in TL and DHA in TL in DHA-enriched infant milk powder that was stored in a sealed container and an opened container at 25°C and 5°C for 24 weeks, as well as the effects of storage temperature and oxygen control on lipid degradation. TL content did not change under any of the experimental conditions. In addition, oxidation of TL was not apparent when oxygen exposure was controlled. However, when the milk powder was stored in an opened container, the oxidation indexes changed during storage, suggesting that lipid degradation occurred. Furthermore, changes in AV and PV at 25°C in the case of oxygen exposure were greater than that at 5°C, so the effect of storage at a lower temperature for lipid degradation was recognized. Analysis of the ratio of NL and CL in TL demonstrated that, similar to the oxidation indexes, controlling oxygen exposure was an effective means of suppressing lipid degradation. However, the difference of storage temperatures did not appear to influence the ratio of NL and CL in TL. The composition of the major fatty acid (18 : ln9, 16 : 0, 18 : 2n6, 18 : 0, 12 : 0 and 14 : 0 acids) composed in TL changed very little under all experimental conditions. Thus, controlling oxygen exposure appears to be an effective means of suppressing oxidative decomposition of fatty acid. Although DHA in CL changed significantly during storage when exposed to oxygen, CL ratio in TL was small, and the resultant changes in TL were barely affected. Based on the results of the present study, if temperature and oxygen exposure are controlled, the physiological effects of DHA can be maintained for a long time.

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The effect of AC high electric field on the oxidative stability of soybean oil was investigated. Four intensities of electric fields of alternating current with a frequency of 60Hz, ranging from 10 to 105kV/m, were applied to soybean oil at different times (10, 30, 60, 120, 480 min, and continuously), which were stored in the dark at 60°C. The increase of the oil weight was determined by weighting method (JOCS), and the conjugated diene and carbonyl value (COV) were determined by absorbance at 234nm and 440nm, respectively. When the soybean oils were treated with 10, 15 and 50kV/m for 60, 120 and 480 min by plate electrode, the oxidative stabilities increased on storage at 60°C, and a preventive effect of oxidation was also shown during storage at high temperature (120t). But by treatment with 15kV/m for continuity and 105kV/m for 120 min in plate electrode, or treatment with 15kV/m or 50kV/m for 120 and 480 min by wire electrode, the oxidative stability decreased. Consequently, the shelf life of soybean oil was considerably improved by treatment with moderate electric fields.

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Effects of light intensity during fruit growth on the occurrence and development of Kohansho in Hassaku (Citrus hassaku Hort. ex Tanaka) fruit were determined when the fruit was stored at 15°C or at 20°C following 5°C storage. Fruit harvested from the sun-exposed exterior canopy developed more Kohansho during storage than those from the interior canopy or covered with a cloth. The sun-exposed side of the exterior canopy fruit was more susceptible to Kohansho than the shaded side of the same fruit. L-Ascorbic acid (AsA) content in the flavedo was higher in fruit from the exterior canopy than from the interior canopy or those that were covered. AsA and total phenol contents in the flavedo were higher on the sun-exposed side than the shaded side of fruit that were taken from the exterior canopy. These results indicated that Kohansho of Hassaku fruit was mainly affected by light condition during fruit growth.

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