Optimization of Soluble Collagen Technology from Trout Skin

¹ Murmansk Arctic University (MAU), Department of Food Production Technologies, 13 Sportivnaya St., Murmansk, 183010, Russia
² Saint Petersburg State University (SPBU), Faculty of Applied Mathematics - Management Processes, 7-9 Universitetskaya Embankment, 199034, St Petersburg, Russia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The aim of this work was to develop and optimize the technology of soluble collagen derived from secondary fish raw materials - waste from the processing of aquaculture products from the Murmansk region (Russia). The raw material used was the skin of lightly salted trout fillets. Standard physicochemical research methods were employed for the study; the organoleptic evaluation of collagen samples was carried out using a 20-point product quality scale developed by the authors, and the results were processed using methods of mathematical statistics. The research included an analysis of the chemical composition of the raw material, which confirmed a high content of protein substances (about 60%) - potential sources of collagen. Due to the high content of fat (8%) and sodium chloride (up to 10%) in the raw material, additional technological steps (fleshing and soaking of the raw material) were introduced to remove them. Special attention was paid to optimizing the aqueous extraction stage: it was found that the yield of the finished product is influenced by the extraction duration, the pH of the extractant, and the temperature conditions of the operation. It was established that conducting extraction in a slightly acidic zone at pH 5.5-5.6 leads to a threefold increase in product yield with the same process duration; increasing the extraction duration from 4 to 8 hours further increases the yield by four times. The research revealed the influence of temperature parameters on the technological indicators of the production process (total collagen yield) and the extractability of protein substances (protein yield). As a result of mathematical data processing, the collagen extraction temperature close to the optimal value was determined to be (44.3 ± 1) °C. The results of the experiments allowed the final technological scheme for the production of dry soluble collagen to be established. Organoleptic and chemical studies determined the quality of the dry soluble collagen sample obtained using the refined technological scheme: the mass fractions of protein, water, fat, and mineral substances were 90.7 %, 6.2 %, 1.9 %, and 1.2 %, respectively, and the product quality level was 94 %. The research results demonstrated the potential of the technological solution for incorporating waste from mariculture product processing into the production of soluble collagen.