Quality Changes in Intermediate Flying Fish, Cheilopogon intermedius Parin, 1961, During Ambient and Ice Storage

Intermediate flying fish, Cheilopogon intermedius, Parin, 1961, is a popular source of inexpensive animal protein in the Philippines, but it remains susceptible to deterioration during processing. The study evaluated the sensory, microbiological, and physico-chemical characteristics of flying fish, C. intermedius stored at ambient conditions (27– 29 °C) and on ice (1–2 °C) storage. The storage duration of flying fish was 8 h at ambient temperature and around 12 days in ice. A ten-member taste panel rejected raw fish due to strong fishy to sour odours and soft texture. Similarly, cooked samples were rejected based on sour and ammoniacal odours, mushy texture, and a bitter taste. Results of sensory evaluation correlated with those of microbial and chemical analyses. Bacteria multiplied rapidly at ambient temperature with values of 11.05 log CFU.g-1 and 7.55 log CFU.g-1 (P < 0.05) for total viable count (TVC), and H2Sproducers count, respectively, at the end of the 20-h storage. In comparison, bacterial counts remained below rejection limits until the end of the storage period for samples stored in ice. Total volatile base nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) accumulated rapidly at ambient temperature, reaching 86.86 mg.100 g-1 and 35.65 mg.100 g-1, respectively, at the end of the storage period. In ice, TVB-N, TMA-N, and histamine values were slowed down, reaching rejection limits only at the end of the storage period. Moreover, the K value increased linearly at ambient storage, while a gradual increase was observed for samples stored in ice. Therefore, without the application of adequate icing, flying fish would undergo rapid decomposition at ambient temperature.