The aim of the study is to determine the influence of enzymatic hydrolysis modes of secondary fish raw materials on the degree of fat extraction from them, the composition of its fatty acids, which are important for the microbial synthesis of biotechnology products. The waste of fish processing plants in the Kaliningrad Region was used as raw materials: hot-smoked sprat heads, mackerel heads and pike-perch internal organs with a fat content of 12.8–22.4 %. Hydrolysis of the raw materials was carried out using the enzyme preparation Alcalase with varying temperature (50–70 ºC), duration (20–60 min), enzyme dosage (0.025–0.6 %). In the experiments, the degree of fat extraction was, in % of the fat content in the raw materials: 60.8–73.6 for sprat; 34.4–53.1 for mackerel; 57.6–80.4 for pike-perch. At minimum values of hydrolysis parameters, the lowest fat yield was noted for all types of raw materials. The maximum parameters had different effects on the fat extraction level. No significant differences in the fatty acid composition of the fats obtained under different hydrolysis conditions were found. The total content of polyunsaturated fatty acids in all fat samples was high: 25.0–27.1 % in sprat; 24.4–27.0 % in mackerel; 29.5–32.5 % in pike-perch. The maximum content of omega-3 PUFAs was found in sprat fat (22.9–23.9 %), and long-chain fatty acids – in mackerel fat (40.7–48.5 %). Taking into account the degree of fat extraction and its fatty acid composition, the following rational parameters are recommended for enzymolysis of fish waste with Alcalase: temperature of 50 °C, duration of 60 min, enzyme dosage of 0.3 %.An analysis of the fatty acid composition and published data allowed the extracted fats to be considered a favorable component for use in substrates for microbial synthesis of biotech products.
Mezenova et al. (Fri,) studied this question.