The influence of pike perch skin tenderization on the process of obtaining juice-containing collagen hydrate and its quality indicators

The influence of preliminary mechanical processing (tenderization) of pike-perch (Sander lucioperca) skin using rotating knife blades of a chopper on the duration of its hydrolysis process (at 4 °C) in directly squeezed apple juice taken in a mass ratio of 1 : 4.5, respectively, was studied. It was shown that mechanical tenderization of fish raw materials for 3-5 minutes (with knives rotating at 1 000 rpm) contributed to a significant reduction (by 3 or more times) in the duration of its acid hydrolysis (hydration) compared to the control (without mechanical processing) and amounted to 20-24 hours, which significantly optimizes the process of obtaining food collagen hydrate from fish skin. The qualitative (organoleptic, physicochemical and microbiological) indicators of food collagen hydrate from pike-perch skin have been determined, which correspond to the requirements of the technical regulation (TR CU 021/2011 “On food safety”). The yield of juice-containing collagen powder obtained from frozen pike-perch skin hydrate during its dehydration in a lyophilizer has been calculated, amounting to 14% of the total weight of the original raw material. The nutritional value of juice-containing collagen powder-lyophilisate has been determined in (%): moisture 8.0 ± 0.7; fat 4.2 ± 0.7; protein 30.0 ± 0.3; carbohydrates 55.8 ± 1.7; ash 2.0 ± 0.01; energy value – 381.0 kcal. It was found that the aqueous suspension obtained from the lyophilisate powder (40 g per 200 ml, respectively, at 20 °C) is highly dispersed and can be used in the production of beverages and food products. According to the conducted research, the development and approval of regulatory documentation (technological conditions and instructions) for “Juice-containing hydrate of fish collagen” is currently underway.