Comparative Sensitivity of Yellowtail Seriolu quinqueradiata and Goldstriped Amberjack S. aureovittata to Photobacterium damsela subsp. piscicida

The pathogenicity of Photobacterium damsela subsp. piscicida to yellowtail Seriola quinqueradiata and goldstriped amberjack S. aureovittata was investigated. The 10-d cumulative mortality of yellowtail and goldstriped amberjack challenged by 1.2 × 10² CFU/fish of P. damsela piscicida was 70% and 10%. respectively. Serum bactericidal activity of goldstriped amberjack was higher than that of yellowtail. Although the phagocytic activity against P. damsela piscicida was not observed in kidney leukocytes of yellowtail and goldstriped amberjack, the production of superoxide anion in goldstriped amberjack kidney leukocytes against P. damsela piscicida was higher than that of yellowtail.     

Changes of multi-drug resistance pattern in Salmonella enterica subspecies enterica serovar typhimurium isolates from food-producing animals in Japan

A total of 153 isolates of Salmonella Typhimurium derived from food-producing animals in Japan between 2002 and 2005 were investigated for antimicrobial resistance and phage types related to definitive phage type 104 (DT104). The predominant resistance type was resistance to ampicillin, dihydrostreptomycin, kanamycin, and oxytetracycline in bovine (45.2%, 48/104) and resistance to dihydrostreptomycin and oxytetracycline in porcine isolates (58.7%, 27/48). DT104-related phage type was found in 32 of 104 bovine isolates, two of 48 porcine isolates, and one of eight isolates from poultry, showing that the proportion of the phage type in S. Typhimurium isolates from cattle and pigs significantly (P<0.01) decreased from 71.9% and 31.4% in 1999-2001 to 30.8% and 4.1% in 2002-2005, respectively.     

Quality improvement by vacuum treatment of boiled skipjack loins for the production of dried skipjack

ABSTRACT: This study attempted to reduce the lipid and water contents in boiled skipjack loins by vacuum treatment and the quality of vacuumed boiled meat was then evaluated during the chilled and frozen storage. The boiled meats were vacuumed at a pressure of 400 Pa for 30 min using a vacuum freeze dryer as an experimental convenience in order to degrease, cool and dehydrate rapidly. The vacuumed boiled meats were stored at 0.0 ± 0.2°C for 10 days and at −20 ± 0.5°C for 90 days. The unvacuumed boiled meats were cooled by air-cooling and stored as the control. Lipid content on a wet basis (w.b.) was reduced as much as 0.5% in the ventral part and 0.4% in the dorsal part of the boiled meats after vacuum treatment. Water content (w.b.) was reduced as much as 2.5% in the ventral part and 3.0% in the dorsal part. The thiobarbituric acid and volatile basic nitrogen values in vacuumed boiled meats were significantly lower ( P < 0.05) than that in unvacuumed boiled meats during storage. Inosine monophosphate (IMP) was only detected as a major nucleotide (about 70%) in boiled meats, and the decomposition of IMP in vacuumed boiled meats was smaller than that in unvacuumed boiled meats during storage. It was concluded that the quality of boiled skipjack loins could be improved by vacuum treatment as a preprocessing procedure in the production of dried skipjack such as katsuobushi .     

Structural identification of new curcumin dimers and their contribution to the antioxidant mechanism of curcumin

As a part of the research project on the elucidation of the chain-breaking antioxidant mechanism of natural phenolics against the oxidation of food components, curcumin, a main turmeric pigment, was investigated. A relatively high concentration of curcumin gave three dimers as radical termination products in addition to the coupling products with curcumin and the lipid hydroperoxide. The structural analysis of these dimers and quantitative analysis of their production rates revealed that radical-radical termination mainly occurred at the 2-position of curcumin. The contribution of the pathway for production of these dimers to the antioxidant mechanism of curcumin was estimated from the concentration-dependent data of the antioxidant activity and formation rates of these termination products. The A-A termination (dimer formation) was estimated to contribute at least about 40% of the entire antioxidant process against ethyl linoleate oxidation.