Changes in protease activity during fermentation of fish sauce and their correlation with antioxidant activity

Abstract

BACKGROUND Antioxidant activity has been found in fermented fish sauce. In this experiment, the properties of endogenous protease and antioxidant activity were studied in anchovy sauce during fermentation. The correlation between protease activity and antioxidant activity in fermented anchovy sauce was analyzed using the partial least squares (PLS) method. RESULTS The results showed that at least four proteases were present in the endogenous enzyme solution, and the optimum pH values were 2.5, 5.5, 9.0, and 12.5, respectively. The maximum inhibition rate of endogenous protease, from high to low, was: serine protease inhibitor > trypsin inhibitor > aspartic protease inhibitor (pepsin inhibitor) > cysteine protease inhibitor > metalloprotease inhibitor. At the sixth month of fermentation, fish sauce had stronger trypsin, pepsin‐like activity, and antioxidant activity. At the ninth month of fermentation, the cathepsin activity was greater. A model correlating changes in protease activity with antioxidant activity suggested that the trypsin and serine protease were the main factors affecting antioxidant activity. CONCLUSION This study reports a model correlating changes in protease activity with the antioxidant activity of fish sauce. It lays a foundation for further exploration of the formation of antioxidant substances and antioxidant effects during the process of fish sauce fermentation. © 2021 Society of Chemical Industry.

Changes in quality components and antioxidant activity of peony seed soy sauce during low‐salt solid‐state fermentation

“…DPPH, a kind of stable free radical, is widely used to evaluate the free radical scavenging activity of natural compounds 29 . The reducing power of a substance could also reflect its antioxidant activity: the higher the reducing power of a substance, the stronger is its antioxidant activity 48 .…”

“…DPPH radical scavenging activity DPPH radical scavenging activity of PSSS was measured according to the method described by Bu et al, 29 with some modifications. Aliquots of 2 mL PSSS solution (20 g L −1 ) were added to 2 mL of 0.1 mmol L −1 DPPH-alcohol solution.…”

“…Antioxidant activity of PSSS at different fermentation stages DPPH, a kind of stable free radical, is widely used to evaluate the free radical scavenging activity of natural compounds. 29 The reducing power of a substance could also reflect its antioxidant activity: the higher the reducing power of a substance, the stronger is its antioxidant activity. 48 Figure 6 shows that DPPH radical scavenging activity and reducing power of PSSS increased from 38.96% to 86.19% and from 0.4806 to 0.8802 (A 700 ) with the extension of fermentation time from 2 to 30 days, indicating that DPPH radical scavenging activity and reducing power of PSSS increased continuously during 30 days whole fermentation.…”

Transforming the fermented fish landscape: Microbiota enable novel, safe, flavorful, and healthy products for modern consumers

“…The diverse endogenous enzymes and microbial enzymes in fermented fish products can be isolated and used as commercial enzyme products to support human health (e.g., protease supplements as digestion aids). Bu et al found that serine protease and trypsin can be obtained from fish sauce (Bu et al, 2022). Healthpromoting probiotic microorganisms can be obtained from fermented fish.…”

“…Bu et al. found that serine protease and trypsin can be obtained from fish sauce (Bu et al., 2022). Health‐promoting probiotic microorganisms can be obtained from fermented fish.…”