The Inhibitory mechanism of onion juice on the browning of shredded lettuce during storage was investigated. Browning and phenylalanine ammonia-lyase (PAL) activity of the control sample dipped in distilled water stored at 5°C increased immediately after cutting. When shredded lettuce dipped in onion juice for 5 minutes, browning and PAL activity of shredded lettuce was suppressed for 48 hours. Polyphenol oxidase (PPO) activity of the shredded lettuce was slightly lower than the control sample, but the rise time of PPO activity was familiar to the control sample. Direct inhibition of onion juice on the PAL activity was not observed at the level of concentration that could inhibit browning almost completely, if treated immediately after cutting. On the other hand, the PPO activity was suppressed about 60% of the control upon the addition of ten percent onion juice in the reaction mixture. However, browning was suppressed negligibly, if the shredded lettuce was treated with onion juice of the concentration immediately after cutting. When the sample turned to brown already after cutting was dipped in onion juice, the Hue angle rised rapidly. After the treatment, browning of shredded lettuce was almost suppressed. The results indicate that onion juice act on the delay in the increase of PAL activity of shredded lettuce, the partial direct inhibition of PPO activity and elimination of color formed by browning reaction. Especially, the inhibition of browning in shredded lettuce during storage mainly depended on the suppression of the increase in PAL activity, if the shredded was treated with onion juice immediately after cutting.

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To confirm the safety of the manufacturing process of uncooked meat products subjected to high pressure treatment, changes of microbiological and physicochemical properties of the product were determined. The changes in the number of microorganisms occurring during the manufacturing process, a decreasing trend in the number of bacteria was observed during cold smoking and dry cooling processes, even though an increase was observed during curing, soaking, and dry cooling processes, and a decrease of 10²-10³CFU/g was observed during high pressure treatment processing. As regard the number of microorganisms as the manufacturing process proceeded, the number Gram-negative bacteria such as Pseudomonas decreased, whereas the number of Gram-positive bacteria such as Micrococcus increased. No remarkable changes in the pH value, Volatile basic nitrogen value, Thiobarbituric acid value and Water activity value used to evaluate quality were noted during the manufacturing process. No food borne pathogenic bacteria were detected at any point during the manufacturing process. The amount of bacteria was less than 10³CFU/g after 3 hours of pressure treatment at 250MPa, and it was inferred that E. coli, S. Enteritidis, S. Typhimurium, P. aeruginasa and A. hydrophila could be inactivated, with the exception of S. aureus. From these results, it was concluded that high pressure processed raw ham was a product that could be produced more hygienically and with higher quality than conventional uncooked meat products.

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The gelatinization properties of cooked and stored Akamai were measured with RVA, andphysical properties and sensory evaluation of gobugayu (gruel) were examined. Based on the RVA measurement results, Akamai with amilling yield of 95% showed a higher tendency of viscosity increase at the starting temperature than Sasanishiki, Haenuki and Akamai. Akamai immediately after cooking showed lower values in maximum, minimum and ending viscosities and breakdown than Haenuki, Sasanishiki and Akamai with amilling yield of 95%. However, the decrease in viscosity by storage and salt addition was not observed. From these results, Akamai was considered able to be used with salt added seasoned cooked rice. Based on the results concerning physical properties of gobugayu (gruel), it was considered that Akamai with amilling yield of 95% was suitable for gobugayu (gruel) since its breaking energy and viscosity of omoyu (gruel liquid) were both low. In the sensory evaluation of gobugayu (gruel), Akamai with amilling yield of 95% was preferred in the total evaluation, while not preferred in viscosity.

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The change in polyphenol content of 'Bartlett' pear (Pyrus communis L.) fruit stored under various conditions was determined, and its relation to the changes in the radical scavenging capacity and the antioxidant capacity of the fruit was investigated. Polyphenolic compounds content was decreased in extended storage period at 2°C or after transferring to 15°C, whereas it increased temporarily in the fruit sealed with 30μm thickness polyethylene bag during storage at 15°C after 50 days storage at 2°C. Chlorogenic acid, catechins and procyanidin 132 decreased in the fruit stored at 2°C, especially in the fruit sealed with polyethylene bags. The change in 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of flesh extract showed the same tendency to the change in total polyphenol content, whereas the antioxidant activity evaluated by the linoleic acid peroxidation system in SDS micell (SDS-LH system) showed different tendency. There was a high correlation between the DPPH radical scavenging activity and the total polyphenol content, whereas the antioxidant activity correlated higher with procyanidin B2 content and lower with the total polyphenol content.

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To improve the quality of thick bean sprouts and clarify their value as a material to supply amino acids, we cultivated thick bean sprouts of soybean and mung bean by the following methods and evaluated their growth and changes in the amino acid contents in the cultivation process and during storage : (1) Routine cultivation method (Control), (2) Carbon dioxide-enriched rotary cultivation (CRC), (3) Dipping in mixed phytohormone treated cultivation (DMP), and Dipping in mixed phytohormone combined application of artificial sunlight lamp cultivation (DPSL). The growth of both types of thick bean sprouts assessed in terms of the marketability of external quality was good in the order of DPSL>DMP>CRC>Control. By each cultivation method, the appropriate harvest time was 5 days after the initiation of cultivation for both types of thick bean sprouts. The total amino acid contents was markedly decreased in the both types of thick bean sprouts compared with beans as a raw material (dry matter). The total amino acid contents began to gradually increase in the early phase of cultivation and markedly increased, reaching a peak, in the middle phase of cultivation (after 3-5 days). This increase was marked in the order of DPSL>DMP>CRC>Control. In the cultivation process of both types of thick bean sprouts by each cultivation method, marked increases were observed in Met, Cys, Phe, Tyr, Thr, Trp, and Leu but slight increases in the other amino acid. Changes in amino acids during storage were similar to those in the cultivation process. The residual contents was the highest after 3 days storage at a temperature of 5±2°C or less. Both types of thick bean sprouts by showed the highest total quality at the time of consumption in terms of extension and appeared to be of value as a material the provides protein and amino acids.

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