The bactericidal effect of heated shell powders and application of seafood preservation

• Main Authors: Pin-Yi Cheng, 鄭品逸
• Other Authors: Yung-Hsiang Tsai, Ph.D.
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/69890307302026451688

碩士 === 國立高雄海洋科技大學 === 水產食品科學研究所 === 97 === The hard clam, oyster, freshwater clam, abalone and purple clam are main five aquaculture shells in Taiwan, and most of them are regarded as commercial waste. The ash contents (%) of five shells calcined at 1000℃ for 1 hour ranged from 52.3% to 55.4%. The bactericidal effects of five calcined shells against food-borne bacteria were studied. It was found that the calcined oyster shell had the higher bactericidal activity. Minimal bactericidal concentrations (MBC) of five calcined shells against Gram negative food-borne bacteria were 0.05% at 3 minutes treatment. However, the MBC of calcined shells against Gram positive, Bacillus cereus and Staphylococcus aureus, were 0.1-0.5% and 0.5-1.0%, respectively, at 3 minutes treatment. The disinfecting effect of oyster-shell powder on oyster meat was investigated for two shell powder concentrations (0.1 and 0.5%) during storage at 4℃. Oyster-shell powder treatment was found to reduce the aerobic plate count for 14 days and V. parahaemolyticus count before 6 days. The 0.1 and 0.5% oyster-shell powder treatments also were found to reduce total coliform at lowing 1-2 log CFU/g and 2-3 log CFU/g, respectively. No significant inhibitory effect was found for TVBN value on control or oyster-shell powder treatment. To elucidate the disinfecting effect of oyster shell powder on peeled shrimp, peeled shrimp meat was presoaked in 0.1% and 0.5% concentrations of oyster-shell powder for 10 minutes and stored at 4℃. It was found that the aerobic plate counts were reduced at 1-2 log CFU/g and 0.5 log CFU/g in peeled shrimp by presoaked 0.5% and 0.1% oyster- shell solution, respectively. However, none of V. parahaemolyticus was detected at 3 days storage in all treatments (including control). In addition, the level of TVBN was reduced in peeled shrimp by presoaked oyster-shell solution, compared to control. Based on the TVBN level (25 mg/100g) for initial decomposition index, the oyster-shell solution could prolong the storage period of peeled shrimp from 8 days to 10 days at 4℃.