The progress in discoloration of Asazuke was different in varieties of chinese cabbage. Contents of total phenol and o-dephenol in leaves were high at harvest, and gradually decreased after Asazuke processing and during storage at 5°C. Parts dissolved into Asazuke liquid. The activities of phenylanine ammonia-lyase and polyphenol oxidase also were high at harvest, and thereafter rapidly decreased. But, the activities of polyphenol oxidase always were higher in the varieties, which were easily discolored. And, they were less sensitive to NaCl. There was no difference in contents of ascorbic acid between the varieties.

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Hassaku (Citrus hassaku Hort. ex Tanaka) and tangor 'Kiyomi' (Citrus sinensis×C. tangerina) fruits stored at 5°C for 3 and 2.5 months, respectively, were dipped in 1% L-ascorbic acid (AsA) solution and then held at 20°C to determine the effects of AsA on the occurrence and development of Kohansho, a peel disorder. AsA content was lower and total phenol content was higher in the flavedo of Kohansho peel than in that of sound peel of both Hassaku and 'Kiyomi' fruits. AsA or sodium erythorbate, an analogue of AsA, treatment as well as 50°C hot-water treatment reduced the occurrence and development of Kohansho of Hassaku fruits. All treated Hassaku fruits maintained a higher AsA content in the flavedo than the water-dipped control until day 3 at 20°C. AsA treatment reduced occurrence and development of Kohansho in 'Kiyomi' fruits. but the inhibition was not retained when held in a polyethylene bag after treatment. AsA content in the flavedo did not differ noticeably between water and AsA dipped 'Kiyomi' fruits. AsA treatment was less effective on 'Kiyomi' than Hassaku fruits. Total phenol content in the flavedo of Hassaku and 'Kiyomi' fruits tended to increase during storage at 20°C regardless of treatment. These results indicate that AsA dip treatment helped in reducing occurrence and development of Kohansho in Hassaku and 'Kiyomi' fruits, and the magnitude of the effects depended on the amount of absorbed AsA by the flavedo tissue.

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The factors affecting the browning in sweetened mei (Japanese apricot) syrup during storage were investigated. When stored at 5, 15 and 25°C for 6 or 12 months, the added sucrose in the syrup was inverted into fructose and glucose as the syrup browning progressed. Increases in 5-hydroxymethyl furfural (HMF), an intermediate of caramelization, were measured in the stored syrups. Experimental rate constants for kinetics of sugar changes and phenolic compound decreases during storage were determined. The browning reaction in sweetened mei syrup was characterized by a combination of oxidation of phenolic compounds and caramelization of sugars.

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To make greater use of ume fruit (Japanese apricot, Prunus mune Sieb. et Zucc.) removed from the liquor, it was investigated whether the low temperature steam-heating process-in which the fruit is heated by steam controlled at temperature intervals between 65 and 80°C, at 90% humidity -is a useful way to prepare the fruit into various processed foods from the constitutional and textural aspect. The analysis of ingredients in fruit samples was carried out on taste components (organic acids and free sugars), amino acids, cyanogenic glycosides and pectic substances before and after the process. Furthermore, the adhesiveness of the paste prepared from the samples was measured in order to examine the effect of the heating process on textural properties of the fruit. One kg 'Nanko' variety of ume fruit contained 1941mg organic acid, 21.8g sugar consisting mainly of glucose and fructose, and 125.7mg amino acid. In the same way, one kg of 'Ohshuku' contained 1730mg organic acid, 21.8g sugar and 234.2mg amino acid. These amounts scarcely changed during the low temperature steam-heating process. Water soluble pectin increased markedly along with the ascent of the steam temperature, but hydrochloric acid soluble pectin decreased reversely. One kg 'Nanko' fruit contained 3mg amygdalin and 9mg of prunasin. 'Ohshuku' fruit contained 10mg/kg of amygdalin and 12mg/kg of prunasin. These cyanogenic compounds exhibited little change throughout the process. The adhesiveness of the flesh paste prepared from the fruit heated by steam showed a trend to increase in accompaniment with the rise of the steam temperature. From these results, it was recognized that the low temperature steam-heating process altered the textural characteristics of the fruit flesh accompanying changes in the solubility of pectic substances, but did not cause resolution or dissolution of taste elements and amino acids. Consequently, it was considered that ume fruit treated by steam can be used as a useful material for various processed foods such as ume caked, seasoned ume pickles and others since the treated fruit is softer than the untreated fruit and contains significant amounts of sugar and organic acids due to material fruit.

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The object of this study was to clarify the effect of experimental hydroponics (water culture : WC) on browning reaction of apple fruits. The changes in total polyphenol (TPP) content and coloration over time after crushing of apple fruits were investigated. The polyphenoloxidase (PPO) activity and property were analysed also. In this study, ripe conventional soil cultured fruits (SCF) and water cultured fruits (WCF) of two cultivars (Fuji and Hokuto) were used. The results were as follows. 1) Regardless of the cultivar, the absorbance of ₄₅₀nm (OD45o) in SCF increased rapidly as time elapsed, but that in WCF increased to half degree of SCF until 60 minutes elapsed gradually. Especially, the OD45o in WCF of Hokuto was inhibited significantly. 2) The reflectance in SCF and WCF (Fuji and Hokuto) showed a similar tendency at OD₄₅₀, which was measured with a spectro color meter. 3) Before browning reaction, there was no difference in the TPP content between WCF and SCF in Fuji. But in Hokuto, the TPP content in WCF was larger than that in SCF. Regardless of the cultivar, the TPP content in SCF decreased over time, especially quickly in the early stage. However the TPP content in WCF decreased slightly. 4) The decrease in the content of TPP due to browning showed a good negative correlation with the degree of enzymatic browning. After all, the TPP content was closely related to the browning degree. 5) The PPO activity was significantly lower in WCF than that in SCF. Isozyme patterns of PPO showed no difference between WCF and SCF. In conclusion, the low browning degree of WCF resulted from the revelation of PPO activity that was inhibited by WC. The browning degree was not affected by the PPO property.

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We evaluated the appropriate storage temperature for thin bean sprouts produced by the conventional culture method and thick bean sprouts produced by growth inhibition by immersion culture in phytohormone solution. The bean sprouts were packed with CPP (30u), for 10 days from immediately after harvest. The appropriate storage temperature was evaluated in terms of maintenance of moisture content, food physical properties, color tone, shape, and freshness during storage compared with those at the time of harvest. The optimal storage temperature in terms of marketability based on appropriate values on the market was 5°C for both thin and thick bean sprouts. At this temperature, thin bean sprouts could be stored for 5 days and thick bean sprouts for 7 days. At 17-20°C, thin bean sprouts could be stored for 1-2 days and thick bean sprouts for 3 days. At 10°C, thin bean sprouts could be stored for 3-4 days and thick bean sprouts for 5 days. Compared with thin bean sprouts produced by the conventional culture method, thick bean sprouts produced by artificial growth inhibition culture showed a wide appropriate storage temperature range (5-10°C), and prolongation of 1-2 days of the storage term with recognized superior storage properties.

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