Evaluation of Chemical Compositions, Antioxidant Capacity and Intracellular Antioxidant Action in Fish Bone Fermented with <i>Monascus purpureus</i>

• Main Authors: Ya-Ting Chen, Shu-Ling Hsieh, Wei-Siang Gao, Li-Jung Yin, Cheng-Di Dong, Chiu-Wen Chen, Reeta-Rani Singhania, Shuchen Hsieh, Shu-Jen Chen
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Molecules
• Subjects: fish bone; <i>Monascus purpureus</i>; antioxidant; Clone-9 cells
• Online Access: https://www.mdpi.com/1420-3049/26/17/5288

Fish bones (FBs) are aquatic by-products that are sources of antioxidant-active peptides, calcium dietary supplements, and biomedical materials. Usually, fermentation of these by-products via microorganisms brings desirable changes, enhancing their value. This study investigates the value addition of FB when fermented with <i>Monascus purpureus</i> (MP) for different time intervals, such as 3 days (F3) and 6 days (F6). The results indicate that the soluble protein, peptide, amino acid and total phenol content, as well as the antioxidant capacity (DPPH, ABTS⁺ radical scavenging activity, and relative reducing power), of F3 and F6 were significantly increased after fermentation. Furthermore, the ROS contents of F3 and F6 were reduced to a greater extent than that of hydrogen peroxide (H₂O₂) in Clone-9 cells. The MMP integrity, as well as the SOD, CAT, and GPx activity, of F3 and F6 were also increased significantly compared to the H₂O₂ in Clone-9 cells. Notably, F3 and F6 displayed significant reductions in ROS content, as well as elevate, SOD activity and MMP integrity in Clone-9 cells, when compared with the native FB. These results indicate that the FBs fermented with MP for 3 days (F3), and 6 days (F6) have antioxidant capacity, with possible applications as natural food supplements.