Microbiological Investigation of Fresh Edible Raw Sea Urchin and its Expiration Date

Abstract

Since no definitive standard exists for setting the expiration date of edible raw sea urchins, it is up to the importer or domestic processing manufacturer to assign an expiration date. In the present study, we performed a microbiological examination of 126 raw sea urchin samples collected from distributors at Tsukiji Market (Tokyo Metropolitan Central Wholesale Market) and evaluated their expiration dates. The expiration dates were set at 5 to 8 days after processing in approximately 80% of the products; however, microbiological examination of the samples indicated that the dates were not sufficiently accurate. Of the products, 27% did not meet the microbiological standards for freshness established by the Tokyo metropolitan government during the period preceding their expiration dates. Our results suggest that the expiration date of edible fresh raw sea urchins should be based on a microbiological examination.

Comprehensive Identification of Bacteria in Processed Fresh Edible Sea Urchin Using 16S Ribosomal DNA Sequence Analysis: The Products Contain Various Food Poisoning-related Bacteria and Opportunistic Bacterial Pathogens

“…3) Previously, we examined 126 processed fresh edible sea urchins obtained from a market and examined the relationship between the expiration date set by the manufacturers or importers and the counts of viable bacteria based on this standard. 4) Approximately 30% of the products did not meet the microbiological standards during the period preceding their expiration dates. Since fresh edible sea urchin cannot be sterilized during the manufacturing process, it is possible for various bacteria, constituting the microflora of sea urchins or contaminants from the environment or human contact during the manufacturing process, to colonize these products.…”