Lipolysis and Lipid Oxidation in Frozen Minced Mackerel as Related to Tg', Molecular Diffusion, and Presence of Gelatin

We determined the sub‐zero temperature dependencies (TD) of lipid hydrolysis (LH), lipid oxidation (peroxide value [PV]), and diffusion of 14 C‐fructose in minced mackerel (MM) and how these rates are influenced by gelatin (G) and MM Tg'. When 1 % G was added, the rate of LH at −10°C decreased as compared to that in controls, whereas the rate of PV and TBARS increased (‐5, ‐15 and ‐20°C). The TD of 14C‐fruc‐tose diffusion was similar to that of TBARS, but not to those for LH or PV. Just below Tg', the rate decrease for TBARS was abrupt, whereas rate decreases for LH and PV were moderate to small, respectively.