Effective Methods in Washing Raw Oysters (Part 1)

Abstract

To find more effective methods washing oyster, several traditional method were examined to retain its freshness and to eliminate bacteria. They were washed being with (1) city water, (2) 3% saline solution, (3) city water or 3% saline solution after mixing oyster with grated radish, and (4) city water or 3% saline solution after swilling out in a Japanese traditional bamboo basket.
Used oyster was the non washing raw ones which were taken out from the shell. Each washing method was as follows : the oyster putted in a bowl was washed three times with twice volume of water.
And then the bacterial counts and TTC-test were examined to find the freshness of the oyster. The results observed were following :
(A) Washing in 3% saline solution proved to be the most effective method in various respects (e.g. the retention of freshness, the elimination of bacterias, etc.).
(B) The third and fourth methods showed more effect when 3% saline solution was used in place of city water.
(C) The bacterial counts of washed raw oyster showed increasing tendency during the storage. But, the trend of increase of bacterial counts in washing one with 3% saline solution only or mixed with grated radish, showed considerably lower rate than other two washing methods.