Phan Dao Thi Anh, Bui Trung Huu, Doan Tram Quynh Thi, Nguyen Nguyen Van, Ly Trieu Hai
Faculty of Chemical and Food Technology, HCMC University of Technology and Education, Ho Chi Minh 70000, Viet Nam.
Research Center for Aquafeed Nutrition and Fishery Post-Harvest Technology (APOTEC), Ho Chi Minh 70000, Viet Nam.
Prev Nutr Food Sci. 2021 Jun 30;26(2):209-218. doi: 10.3746/pnf.2021.26.2.209.
Melanosis in shrimp usually leads to reduction in its shelf life and quality, which causes a significant loss in economic value of shrimp products. This study reports potential applications of nine ethanolic extracts of by-products, i.e., peel and/or seed from three Vietnamese avocado varieties as effective inhibitors of melanosis in whiteleg shrimp. Six out of nine shrimp samples treated with the prepared extracts (0.025%, w/v) reduced melanosis and lipid oxidation more significantly as compared to those treated with sodium metabisulfite (SMS, 1.25%, w/v) and control groups (treated with water) during 8-day storage at 4°C (<0.05). These six extracts had mean gray values ranging from 47.0±0.7 to 57.3±0.4% were lower than those treated with SMS (mean gray of 39.8±0.4%). The inhibition of melanosis and lipid oxidation in shrimp for these extracts could be attributed to their high content of polyphenols [total phenolic content (TPC) from 44.5±1.1 to 144.7±1.9 mg gallic acid equivalents/g dried weight] and strong antioxidant activities [including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), and tyrosinase enzyme inhibition]. Pearson statistical analysis showed strong correlation for melanosis inhibition to TPC and DPPH scavenging (r>0.80) followed by tyrosinase inhibition and FRAP (r>0.50). The findings obtained from this study suggest potential utilization of avocado by-product extracts as safe and cheap natural alternatives to traditional sulfites for anti-melanosis and shelf life extension of whiteleg shrimp.
虾的黑变病通常会导致其货架期和品质下降，从而造成虾产品经济价值的重大损失。本研究报道了来自三种越南鳄梨品种的果皮和/或种子等九种副产品乙醇提取物作为凡纳滨对虾黑变病有效抑制剂的潜在应用。在4℃下储存8天期间，用制备的提取物（0.025%，w/v）处理的九个虾样本中有六个比用焦亚硫酸钠（SMS，1.25%，w/v）处理的样本和对照组（用水处理）更显著地减少了黑变病和脂质氧化（<0.05）。这六种提取物的平均灰度值在47.0±0.7%至57.3±0.4%之间，低于用SMS处理的样本（平均灰度为39.8±0.4%）。这些提取物对虾黑变病和脂质氧化的抑制作用可能归因于其高含量的多酚[总酚含量（TPC）从44.5±1.1至144.7±1.9毫克没食子酸当量/克干重]和强抗氧化活性[包括2,2-二苯基-1-苦基肼基（DPPH）自由基清除、铁还原抗氧化能力（FRAP）和酪氨酸酶抑制]。Pearson统计分析表明，黑变病抑制与TPC和DPPH清除之间存在强相关性（r>0.80），其次是酪氨酸酶抑制和FRAP（r>0.50）。本研究结果表明，鳄梨副产品提取物有可能作为安全廉价的天然替代品，替代传统亚硫酸盐用于凡纳滨对虾的抗黑变病和延长货架期。
