Clostridium botulinum type E outgrowth and toxin production in vacuum-skin packaged shrimp

Abstract

White and brown shrimp (Penaeus spp.), harvested from the Georgia coast, were inoculated with log 3-4 spores of a mixed pool of four strains of Clostridium botulinum type E (Beluga, Minnesota, G21-5, and 070). Oxygen barrier film was used to vacuum-skin package the shrimp. Packaged shrimp was stored at either 4°C or 10°C. Storage at 10°C was used to simulate temperature abuse. Anaerobes were enumerated by Most Probable Number method using TPYGT broth incubated in anaerobic jars. Clostridium botulinum toxin production was evaluated using the mouse bioassay. After six days at 10°C, botulinum toxin was detected in the packaged shrimp, but the shrimp was noticeably spoiled at this point. No botulinum toxin was detected in the packaged shrimp stored at 4°C for 21 days, although spoilage was noted after 6 days.