短期净养系统对带壳牡蛎品质的改善作用

为解决牡蛎肉质洁净度难以保证的问题,设计了一种一体式短期净养系统作为牡蛎进一步加工前的暂养技术,包括净养池、过滤装置、蛋白泡沫分离装置、紫外杀菌装置及制冷装置等。分别针对复原海水盐度(0.00、0.85、1.70、2.55、3.40 g/100 mL)、水体循环、贝水质量比(1∶400～1∶22.5)3个因素对带壳牡蛎品质的影响进行单因素试验。结果表明:当复原海水盐度为2.55 g/100 mL,同时进行伴有过滤、蛋白泡沫分离、通氧等装置的水体循环时,净养24 h后带壳牡蛎存活率为98.3%,肉质盐度为2.55 g/100 mL,洁净度最高;此外,贝水质量比为1∶30时,牡蛎存活率和肉质洁净度能够得到保证,水体菌落总数上升较贝水质量比为1∶22.5减慢72.6%;进一步将短期净养系统与置于装有蓄冷冰袋的普通泡沫箱暂存相比,带壳牡蛎的存活期延长87.5%,贮藏5 d时菌落总数降低约0.4(lg(CFU/g)),说明该短期净养系统能有效延长带壳牡蛎进一步加工前的暂存保质期。

Effect of Temporary Cultivation System on Improving the Quality of Oysters

In order to solve the problem in difficulty in ensuring the cleanness of oyster flesh, an all-in-one temporary cultivation system consisting of a cultivation pool, a filtering device, a protein foam separation device, an ultraviolet sterilization device, a refrigeration device, etc. was designed for fresh oysters to be processed. The effects of the salinity of reconstituted sea water (0.00, 0.85, 1.70, 2.55 and 3.40 g/100 mL), water circulation and oyster-to-seawater ratio (1:400–1:22.5, m/m) on the quality of oyster were investigated by one-factor-at-a-time method. Results have showed that when the salinity of reconstituted sea water was 2.55 g/100 mL and water circulation was carried out with the filtering device and the protein foam separation device under aerobic conditions, the survival rate of oysters was 98.3%, the salinity of oyster flesh was 2.55 g/100 mL and the cleanness of oyster flesh was highest after cultivation for 24 h. Both the survival rate of oysters and the cleanness of oyster flesh were high when oyster-to-seawater ratio equaled 1:30, and the rate of increase in total bacterial count in the water was slowed by 72.6% compared with that at an oyster-to-seawater ratio of 1:22.5. The survival period of oysters in the temporary cultivation system was prolonged by 87.5% compared with that in common foam boxes with ice packs, and on the fifth day of storage, the total bacterial count was decreased by 0.4 (lg(CFU/g)), indicating that the temporary cultivation system could effectively prolong the storage period of oysters before processing.