| Refrigeration time and temperature during processing and distribution affect the quality and safety of seafood products. Microbiological assessment, biogenic amine determination, and sensory analysis were performed on fresh salmon, mahi-mahi, and tuna stored at different temperatures for various time periods. Color, texture, appearance, and odor were evaluated by a trained sensory panel, while aroma/odor was evaluated using an AromaScan. Bacterial enumeration was performed using aerobic plate count (APC) agar containing 1.5% NaCl and incubated for 48 hr at room temperature. Histamine-producing bacteria were isolated from salmon and tuna fillets using Niven's differential medium and identified by API 20E strips. Histamine was determined using capillary electrophoresis (CE) and AOAC fluorometric method. Biogenic amines were determined using a gas chromatograph (GC) after derivatization. The objectives of this study were (1) to correlate the degree of agreement among bacterial numbers, sensory analysis, biogenic amine levels, and AromaScan evaluation for quality determination of salmon, mahi-mahi, and tuna and (2) to determine the applicability of these methods for quality determination of the a above-tested seafood.; Storage temperature and microbial counts played important roles in the spoil, spoilage of fresh seafood. The change in quality correlated with increases in microbiological measurements. Monitoring bacterial levels is a useful objective indicator of gross spoilage and the presence of histamine hazard in mahi-mahi and tuna.; Histamine level has little value in monitoring the loss of freshness that occurs fish fillets during storage at different temperatures. Biogenic amines may be used as quality and safety indicators for mahi-mahi and tuna. Very good correlations (r2 > 0.99) were found among AOAC, CE, and GC methods for determination of histamine in tested mahi-mahi and tuna samples. The CE method may offer an alternative procedure for rapid screening and determination of histamine in seafood. The GC procedure for simultaneous analysis of 5 putrefactive amines provides a useful tool for assessing these chemical indicators in spoiled seafoods.; Human sensory analysis provides a useful means to monitor both changes in freshness and the onset of spoilage. In determination of seafood quality, good correlation exists between AromaScan and sensory analysis, and AromaScan and bacterial counts. AromaScan analysis may provide a viable, quantitative approach to determine fish freshness which could be used for quality control and inspection purposes. |
