Antibacterial activity and preservative properties of thinned young apples extracts for fish flesh

Abstract

The content of polyphenols from thinned young apples (TYA) is higher than that in ripe apples. Polyphenols have been reported to show a variety of biological activities. Antibacterial activities were tested at three different percentages of TYA extracts of 0.05, 0.1, and 0.2% on 53 bacterial strains, and the validity of minimum inhibitory concentration (MIC) was investigated. To evaluate preservative properties of TYA extracts for fish cubes at 4 °C in refrigerator, fish cubes were treated with 0.1% TYA extracts and potassium sorbate (PS) solution (0.075 g/kg fish flesh). Results revealed that TYA extracts showed significant antibacterial activity against 18 strains out of selected 53 bacterial ones, with MIC values ranging from 256 to 2,048 µg/mL. The 0.1% TYA extracts can inhibit the increase of pH value and control malondialdehyde more efficiently than PS at the same concentration. Interestingly, The 0.1% TYA extracts also suppressed total volatile basic nitrogen value and reduced total bacteria counts only in storage for 2 days than PS. Practical applications China Association for Ethical Studies has approved the study, and all experiments were performed per the approval of the Institutional Animal Care and Use Committee.