Toxicity Change of Paralytic Shellfish Poison-infested Oyster during Canning, Drying and Sauce-making Processes

Abstract

Paralytic shellfish poison-infested oysters (about 30 MU/g) were smoked or boiled and then canned. Dried oyster and oyster sauce were also produced. The toxicity of canned smoked oyster decreased to under the quarantine limit (4 MU/g) or to an undetectable level (< 2 MU/g). A similar result was obtained in canned boiled oyster. It seems possible to use contaminated oysters safely as canned foods. In the production of oyster sauce, over 90% of the toxicity was destroyed during condensation (6 hrs of boiling in a water bath). As the toxicity of the starting material of oyster broth was under 5 MU/g (usually 2~4 MU/g), the oyster sauce produced also cleared the official quarantine limit successfully. On the other hand, the dried oyster product retained a high level of residual toxicity (7 MU/g) and was still hazardous. © 1995, Japanese Society for Food Hygiene and Safety. All rights reserved.