Influence of vibration by practical or simulated transportation on respiration rates and chemical components of Broccoli (Brassica oleracea var italica) heads was examined. Acceleration data of practical vibration were actually recorded by truck transportation, and the simulated vibration experiment was performed with a trans-simulation vibrator in the laboratory. The 0.5-1.5G of vibrating acceleration was observed on the ordinary roads, while more than 2G obtained occasionally, depending on road condition. Before the vibration, the respiration rate (CO₂ production) of broccoli was approximately 250mg·kg^-1·hr^-1 at 15°C and 80mg·kg^-1·hr^-1 at 5°C. The respiration rate gradually increased to 280 mg·kg^-1·hr^-1 at 15°Cand 110mg·kg^-1·hr^-1 at 5°C for the first 20 min and then remained constant during the vibration. After the vibration, the respiration rate decreased to the initial level within 1 hr.Practical and simulated vibration did not affect counts of total soluble sugar, ascorbic acid and chlorophyll, stem firmness and freshness of broccoli.

View full abstract

Suppressive effects of green tea polyphenols (GTP), which contain (+) -catechin, (-) -epicatechin, (-) -gallocatechin, (-) -epigallocatechin, (-) -gallocatechin gallate, (-) -epicatechin gallate and (-) -epigallocatechin gallate, on microbial growth and volatile basic nitrogen (VBN) content in the cultured fish meat were investigated. The moist pellets supplemented with different concentrations of GTP (0, 0.02 and 0.2% (w/w)) were fed to young yellowtails (Seriola quinqueradiata) of 0-year fish. These fish were killed on the 4th week after feeding. The numbers of microbial and psychrophilic bacteria in their meat were counted during ice storage of the round fish. The contents of VBN, which are known as their bacteria metabolites, content in the meat, were also determined. The increase of microbial counts and psychrophilic bacteria counts in their meat were suppressed by GTP feeding. The increase in VBN of their meat were also suppressed. The feeding of 0.2% GTP were more effective than that of 0.02% GTP. Thus, it was suggested that GTP were effective to control microbial growth and to maintain freshness of the meat during delivery of cultured fish.

View full abstract

Four prototype ethylene scrubbers that were composed of palladium chloride-activated carbon filter and blower were produced in order to establish the assess method for the performance of scrubbers. For the assessment of ethylene removing speed, the atmosphere in the gas-tight prefabricated walk-in refrigerator (6 m³ at 3°C) was replaced with 13 ppm of ethylene, then the ethylene concentration was monitored. The half reduce time was shortened from 12 to 1. 5 hours by using 1 to 4 scrubbers. The ethylene removing speed was successfully evaluated by the proposed method because higher performance of scrubber resulted in the rapider removal of ethylene. To assess the effect of scrubbers on prevention of ethylene accumulation in storage room, 1 % ethylene was continuously supplied into the refrigerator at the rate of 2 ml/min, then the ethylene concentration was monitored. A reliable method to evaluate the performance was established because the increase in the number of scrubbers used gave more effective prevention of ethylene accumulation. Commercial type ethylene scrubber was developed and its performance was assessed by the mentioned methods. The supplemental tests, long period test and ripening inhibition test of mini-tomatoes, suggested the high performance of the scrubber.

View full abstract

Lysozyme was glycosylated with dextran by the Maillard reaction in a controlled dry-heating state. The lysozyme activity and antimicrobial effects on the Gram-negative bacteria were observed in the glycosylated lysozyme (gLz). In this research, the actual efficiencies of gLz as a food preservation were investigated. The addition of gLz inhibited the growth of E. coli in the cottage cheese. These effects were also found in the Edam and Ricottone type cheese without inhibition of their ripenings. These result could suggest the promising possibilities of gLz as the food preservative.

View full abstract