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The objectives of this study were to characterize volatile compounds and to determine the characteristic aromas associated with impact compounds in 4 fish sauces using solid-phase micro-extraction, gas chromatography-mass spectrometry, Osme, and gas chromatography olfactometry (SPME-Osme-GCO) coupled with Stevens' Power Law. Compounds were separated using GCMS and GCO and were identified with the mass spectral database, aroma perceived at the sniffing port, retention indices, and verification of compounds by authentic standards in the GCMS and GCO. Aromas that were isolated and present in all 4 fish sauce samples at all concentrations included fishy (trimethylamine), pungent and dirty socks (combination of butanoic, pentanoic, hexanoic, and heptanoic acids), cooked rice and buttery popcorn (2,6-dimethyl pyrazine), and sweet and cotton candy (benzaldehyde). All fish sauces contained the same aromas as determined by GCO and GCMS (verified using authentic standard compounds), but the odor intensity associated with each compound or group of compounds was variable for different fish sauce samples. Stevens' Power Law exponents were also determined using this analytical technique, but exponents were not consistent for the same compounds that were found in all fish sauces. Stevens' Power Law exponents ranged from 0.14 to 0.37, 0.24 to 0.34, 0.09 to 0.21, and 0.10 to 0.35 for dirty socks, fishy, buttery popcorn, and sweet aromas, respectively. This demonstrates that there is variability in Stevens' Power Law exponents for odorants within fish sauce samples.

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Sodium or potassium salts such as lactate and acetate can be used to inhibit the growth of spoilage bacteria and food-borne pathogens, and thereby prolong the shelf-life of refrigerated seafood. However, minimal information is available regarding the combined effects of potassium salts (acetate and lactate) with an agglomerated phosphate blend on the quality and safety of refrigerated catfish fillets. The objective of this study was to determine the microbiological and quality characteristics of marinated catfish fillets treated with organic acid salts. Catfish fillets were vacuum-tumbled with a brine solution with and without the added organic acid salts, at 10% over initial, raw weight prior to tray-packing and storage at 4 °C for 14 d. Fillets were evaluated for yields, color, pH, tenderness, consumer acceptability, and shelf-life. No differences (P > 0.05) existed among the treated and untreated fillets with regards to solution pick-up and pH, but all treated fillets increased (P < 0.05) cooking yields and Intl. Commission on Illumination (CIE) a* values, and decreased (P < 0.05) CIE L* and b* values in the catfish fillets when compared to the untreated fillets. The fillets treated with a combination of potassium acetate and potassium lactate had lower (P < 0.05) psychrotrophic plate counts and lower spoilage scores than the control treatments on days 7, 10, and 14. In addition, consumers preferred (P < 0.05) treated catfish fillets (fried) with respect to appearance, flavor, and overall acceptability over the negative control. In conclusion, the combination of potassium acetate and potassium lactate enhanced sensory quality and extended the shelf-life of refrigerated catfish fillets.