Proteolytic Activity in Four Low-Trophic Marine Species from the North Atlantic: Effects of pH and Temperature Across Species

Low trophic marine species are rich in nutrients, making them valuable for food and feed applications. However, these species contain endogenous enzymes that quickly lead to the rapid deterioration of the raw material after harvest. This study investigates how temperature and pH influence proteolytic enzymes in Calanus, krill, Benthosema glaciale, Maurolicus muelleri, and an unsorted biomass sample. Protease activity peak occurred at 50°C for all species, and temperatures above 60°C reduced activity. Across species, Calanus showed the highest proteolytic activity. Future research should focus on enzyme characterization and technological processes to control enzymatic activity while preserving nutrient quality.