The antifungal activities of caffeic, p‐coumaric, ferulic, and chloro‐genie acids against Saccharomyces cerevisiae were investigated. Caffeic acid was found to exhibit little inhibition of growth, although the lag period was extended in the presence of 1000 ppm. Chloro‐genie acid had no effect on the organism. In contrast, p‐coumaric acid at 100 ppm increased the lag phase of S. cerevisiae, and above 250 ppm, inhibition after 72 hr growth was proportional to the concentration present. Ferulic acid caused an increase in lag phase at 50 ppm, while as little as 250 ppm resulted in complete inhibition. These results suggest that naturally occurring hydroxycinnamates may interfere with the fermentation of fruits by this yeast.

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The lipid, iron, myoglobin, and hemoglobin contents and the time for extracted lipids to gain 1% weight (a measure of autoxidation potential) were measured in 12 samples of six fish species. These were taken singly and in combination to prepare models to predict the shelf life of frozen minced fish, based on thiobarbituric acid reactive substance levels. By using only the potential for the extracted lipids to autoxidize, a reasonably accurate model was obtained (R* = 0.83). Incorporating some of the compositional factors into the models improved the simple model. These models could be useful in providing fairly rapid estimation of the TBA number based shelf-life of frozen minced fish.

Decomposition and histamine formation were studied with fresh mahimahi (Coryphaena hippurus) incubated in seawater at 0, 10, 21, and 32°C. The rates of decomposition (loss of quality) and histamine formation both increased at warmer incubation temperatures. Spoilage bacteria were primarily psychrotrophic at 0 and 10°C, while mesophilic bacteria predominated at 21 and 32°C. An increase in pH of the loin tissue was correlated slightly with the histamine level. The correlation between histamine level and loss of quality, however, was high. Also there was a strong correlation between odor of the fillet and histamine production during spoilage. Prior frozen storage at −20°C inhibited the rate of subsequent histamine formation, but did not affect the extent of quality loss. Loss of histamine during cooking (baking or steaming) had no appreciable effect on the residual histamine level of spoiled fish. Seawater was a much more efficient heat transfer medium than air during incubation. The rates of histamine formation and loss of quality were significantly greater in seawater than in air at the same temperature.