Chemical Composition and Time–Temperature Arrhenius Modeling for Shelf-Life Prediction of Olive Flounder (Paralichthys olivaceus) By-Products

This study investigated the time-temperature stability of olive flounder by-products (OFB) to support their use as raw materials. Five parts (head, tail, skin, viscera, and trimmings) and a mixed OFB sample were analyzed for proximate composition, fat-soluble vitamins, fatty acids, minerals, and heavy metals. The mixed OFB was stored at 5, 10, and 25 °C for up to 48 h, while total bacterial count (TBC), pH, volatile basic nitrogen (VBN), biogenic amines (BAs), fatty acid composition, and acid value (AV) were monitored and modeled using first-order and Arrhenius kinetics. Skin and trimmings showed the highest protein levels, whereas viscera had the greatest lipid and retinyl acetate content; α-tocopherol was predominant in most tissues. The major minerals detected were Ca, S, and P, and heavy metals remained below safety limits. During storage, TBC increased, and pH initially decreased with increasing temperature. At 5 °C, putrescine and cadaverine were the main BAs, whereas the histamine content was negligible; at 10 and 25 °C, histamine and tyramine content increased markedly, with histamine reaching 88.65 mg/kg at 25 °C, AV was low at 5 °C but exceeded rancidity thresholds at higher temperatures. Overall, the kinetic modeling indicated practical use limits of 30 h at 5 °C and 6 h below 30 °C.