| 英文摘要 |
The bulk breeding and in-pool cultivation technologies of clam seed had been built in Taiwan, and the output reached 30 kilotons each year. The main cultivated regions of clam are Jhanghua and Yunlin County, in which the annual output was 60-90% of the whole island. The major possible hazard factors that could cause heavy metal pollution, drug or antibiotics residuals, and hazard from microorganisms are the water quality, soil, surroundings, and inadequate use of feed or drugs. After the investigations and analyses, the results showed that the water quality was the most possible hazard, followed by the polluted soil from the bottom of the cultivation pools. Therefore, we gave every effort to popularize the good production resumes and help the cultivators passing the certifications of good farms. Clams are usually commercially sold in patterns of fresh clams, pickled clams, and shucked clams. The retail way of fresh clams is described as follows: the distributors purchase fresh clams from the cultivators, then the trading transporters auction the clams in fish markets, or sell them to the smaller distributors. The cultivators and consumers wouldn’t benefit from these procedures, while the distributors and trading transporters earn most of the profit. Consequently, promoting the small and vacuum packages of clams could establish another mode of trading. The experiments compared the packaged fresh clams with the packaged shucked clams in different storage conditions. The results indicated that vacuum packaged clams with shells had better freshness during spring. In the aspects of sensory evaluations and chemical analyses, the vacuum packaged clams exhibited longer acceptable durations, which still showed good quality before 20 days. In the other hand, the sensory evaluation scores of normal packaged clams reduced quickly after 15 days, and the chemical indicators, VBN and TMA, were over 15mg/100g after 15 days and the K value also increased speedily. The shucked clams were better preserved under carbon dioxide packaged condition, which were better than vacuum or nitrogen packages in both viable counts and chemical indicators, though the viable counts of normal packages were not beyond the hygienic standard (106/g) until the tenth day. After harvest, the sand of the clams must be vomited and the shell must be decolorized. Through the construction of sea water integrated supplying system, the sand-containing possibility could be reduced and the quality of clam could be ensured. The manufacturing process of pickled clams doesn’t involve heating operations; as a result, the examination of Vibrio parahaemolyticus on commercial products exhibited positive reaction. Therefore, the addition of heating operations in processing and management is recommended in the future. The establishment of good package specifications and meet the requirements of HACCP, aid to construct safety and hygiene monitoring systems and management regulations, conclude correct labeling items, and the proprietors of clams, the fishery production group and the cooperative society to conduct modern production and marketing system, and promote Taiwan clams into international level, to reach our common objectives. |