Characterization of protease and effects of temperature and salinity on the biochemical changes during fermentation of Antarctic krill

• Published in: Journal of the Science of Food and Agriculture
• Main Authors: Fan, Yan, Tian, Lili, Xue, Yong, Li, Zhaojie, Hou, Hu, Xue, Changhu
• Other Authors: National Natural Science of China, Shandong Province Science and Technology
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Antarctic; Antarc*; Antarctic Krill
• Online Access: http://dx.doi.org/10.1002/jsfa.8209; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjsfa.8209; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jsfa.8209

Abstract BACKGROUND Despite their abundance, Antarctic krill are underutilized because of numerous difficulties in their commercial processing. Ideally, fermentation technology can be applied to transform them into a popular condiment. In addition to the exploration of protease properties, the present study aimed to evaluate proteinase activity, pH , amino nitrogen, and histamine formation during fermentation at different temperatures and salt treatments. RESULTS Even though the activity of Antarctic krill protease reached a maximum at 40 °C and pH 7, it was stable at 30 °C and pH 7–9. Among the metal ions tested, Ca 2+ , Mg 2+ and K + increased protease activity, in contrast to Zn 2+ and Cu 2+ . Within each treatment, the highest protease activity and amino nitrogen content, as well as the lowest histamine level, were observed on day 12 of fermentation. Treatment at 35 °C with 180 g kg –1 salt led to the production of maximum amino nitrogen (0.0352 g kg –1 ) and low histamine (≤0.0497 g kg –1 ). CONCLUSION Krill paste fermented for 12 days at 35 °C with 180 g kg –1 salt exhibited the optimal quality and properties, suggesting an efficient method for fermentation of Antarctic krill and other aquatic resources. © 2017 Society of Chemical Industry