This study aimed to extract and evaluate some properties and the capability of phenolic components from shallot (Allium ascalonicum L.) peels for usage as fish preservative. It was found that shallot peels extracted twice with 70 % ethanol solvent, within 60 minutes, at 60 oC and the ratio of solid/liquid 1/20 (g/mL) gave highest polyphenol and flavonoid yields. Total polyphenol content and total flavonoid content of the extract were ± mg GAE/g DW and ± mg QE/g DW, respectively. | Cite this paper Vietnam J. Chem. 2023 61 2 253-261 Research article DOI Shallot peel Allium ascalonicum L. extract the antioxidative antibacterial properties and fish preservation capacity Phan Thi Hoang Anh1 2 Le Thao Gia Truc1 2 Tran Thi Tuong An1 2 1 Ho Chi Minh city University of Technology HCMUT Ho Chi Minh City 268 Ly Thuong Kiet Street District 10 Ho Chi Minh City 70000 Viet Nam 2 Vietnam National University Ho Chi Minh City Linh Trung Ward Thu Duc District Ho Chi Minh City 70000 Viet Nam Submitted August 9 2022 Revised October 1 2022 Accepted November 22 2022 Abstract This study aimed to extract and evaluate some properties and the capability of phenolic components from shallot Allium ascalonicum L. peels for usage as fish preservative. It was found that shallot peels extracted twice with 70 ethanol solvent within 60 minutes at 60 oC and the ratio of solid liquid 1 20 g mL gave highest polyphenol and flavonoid yields. Total polyphenol content and total flavonoid content of the extract were mg GAE g DW and mg QE g DW respectively. The extract demonstrated potent DPPH scavenging capacity with IC50 value of µg mL and high antibacterial activities on Bacillus subtilis Escherichia coli and Staphylococcus aureus with MIC values were 224 160 and 224 µg mL respectively. Through measuring PV TBARS values of basa catfish fillets coated with the extract suspension it was observed that shallot peel extracts could strongly inhibit lipid oxidation. Suspension of 3 extract displayed inhibitory capacity comparable to that of 200 ppm BHT a commercially employed antioxidant after 3 days in refrigerator conditions 4 C and up to 4 weeks in deep-freezing conditions -18 C . Keywords. Allium ascalonicum L. shallot peels preservation basa catfish. 1. INTRODUCTION that onion skin extracts also displayed potent antioxidant activity and DPPH radical quenching Shallot Allium ascalonicum L. is a very common capacity comparable
