Feasibility Study on the Determination of Fish Freshness by Trimethylamine Headspace Analysis

Abstract

Trimethylamine (TMA) concentration in fish tissue is an accepted measure of deterioration. In this preliminary study a direct relation was demonstrated between TMA in the tissue and in the headspace above the fish flesh. A relatively simple but precise procedure was developed for measuring TMA headspace concentration, based on air sampling with Carbotrap or Tenax sorbent tubes and subsequent thermal desorption and gas chromatographic (GC) analysis. Sampling and analysis are completed in less than 5 min. Fish freshness determined by TMA headspacc analysis was consistent with grading estimated by sensory tests, but the instrumental method provided a more objective and quantitative assessment of quality and an estimation of postmortem age of the fish.

Histamine and Histamine-Forming Bacteria in <i>Keropok lekor </i>(Malaysian Fish Sausage) during Processing

“…Meanwhile, the TMA level might be generated by a complete reduction of TMAO to TMA by microorganisms (Hansen et al, 1996, Ababouch et al, 1996. This is also in line with the findings of other researchers (Hebard et al, 1982;Fernandez-Salguero and Mackie, 1987;Huss, 1988;Krzymien and Elias, 1990;Koutsoumanis and Nychas, 1999) which had also reported higher levels of TMA due to decomposition of TMAO, as a result of bacterial spoilage and enzymatic activity under favourable temperature and pH conditions. Moreover, higher TMA values might also be associated with the post-harvest handling conditions involving bacterial contamination of fish muscle (Chytiri et al, 2004).…”

Quality changes of anchovy (Stolephorus heterolobus) under refrigerated storage of different practical industrial methods in Thailand

“…TMA-N is considered a valuable tool in the evaluation of the quality of fish stored in ice because of its rapid accumulation in muscle under refrigerated conditions (Kryzmien and Elias 1990). In this study, the production of TNA-N followed a similar pattern to TVB-N during refrigerated storage, where a significant increase was observed with storage time (p≤0.05).…”

Effect of slaughter methods on the quality of Chilean jack mackerel (Trachurus murphyi) during refrigerated storage

“…In fresh or iced fish TMAO is reduced by bacterial enzymes to TMA (Krzymien and Elias 1990). TMA is widely used as a valuable tool to evaluate the quality of fish stored in ice because of its related to the deterioration of the fish under refrigerated conditions.…”