Freshness indicator, seafood

Cheeses, conjugated dienoic derivatives of linoleic acid, 263,267r Chelators, 57-58 Chemesthesis, sensation based on generalized membrane response, 15,16/ Chemesthetic stimulants, description, 21 Chemical analysis of seafood freshness indicators, 250... 

VIII. Amine Formation as an Indicator of Freshness in Seafoods... 

Oehlenschlalager, J. 1997. Suitability of ammonia-N, dimethylamine-N, trimethyl-amine-N, trimethylamine oxide-N and total volatile basic nitrogen as freshness indicators in seafood. In Methods to Determine the Freshness of Fish in Research and Industry. Nantes Conference, November 12-14. 

Currently available methods for determining seafood freshness have been reviewed (2,3,4,5). In general, sensory and microbiological quality of seafoods are the standards most often utilized for determining freshness. There are, however, several limitations with these methods such as the need for trained technicians, problems with subjectivity, or long analysis times. Consequently, several new methods have been proposed using chemical indices of freshness that attempt to overcome these difficulties. The purpose of the present paper is to first review these methods with particular emphasis on shrimp freshness determinations and, secondly, to present experimental evidence showing that impedance can be used to denote shrimp freshness. 

For many foods one of the most important quality criterion is freshness. This is especially so in numerous species of vegetables, fruits, and seafood. Fish of valuable species at the state of prime freshness, suitable to be eaten raw, may have a market price that is ten times higher than that of the same fish after several days of storage in ice but still very fit for human consumption. The characteristic freshness attributes of different foods are usually evaluated by sensory examination and by determination of specific indices, e.g., nucleotide degradation products in fish. 

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