PDF(Pubmed)
Abstract：
Shrimp has been known for its delicacy, but it undergoes rapid deterioration induced by biochemical and microbiological reactions. Melanosis is a major cause of discoloration associated with consumer rejection. All ethanolic extracts from different leaves including soursop, noni, and Jik leaves were dechlorophyllized via the \"Green\" sedimentation method before being used. The inhibitory activity against polyphenoloxidase (PPO) from Pacific white shrimp (Litopeneous vannamei) and the copper-chelating properties of varying extracts were compared. Soursop leaf extract (SLE) showed higher PPO inhibitory activity and copper-chelating ability than others (p < 0.05). Based on LC-MS, aempferol-3-O-rutinoside was identified as the most abundant compound, followed by catechin and neocholorigenic acid. The efficacy of SLE at different levels (0.25-1%) for inhibiting melanosis and preserving the quality of Pacific white shrimp was evaluated during refrigerated storage at 4 °C for 12 days in comparison with that of a 1.25% sodium metabisulfite (SMS)-treated sample. SLE at a level of 1% effectively retarded melanosis and bacterial growth, in which the total viable count did not exceed the microbial limit within 12 days. In addition, 1% SLE treatment impeded autolysis, reduced protein degradation and decomposition, and minimized lipid oxidation, as witnessed by the lower increases in pH, TVB-N, and TBARS values. Sensory evaluation indicated higher likeness scores and overall acceptability for SLE-1% and SMS-1.25% shrimps than those of the control and other samples. Therefore, SLE could be used as a natural alternative that effectively lowered the melanosis and quality loss of shrimp during refrigerated storage.
摘要：
虾以其美味而闻名，但是它经历了生化和微生物反应诱导的快速恶化。黑变病是与消费者排斥反应相关的变色的主要原因。来自不同叶子的所有乙醇提取物，包括soursop，诺丽,和Jik叶在使用前通过“绿色”沉降法脱氯。比较了对太平洋白虾（Litopleeasevannamei）的多酚氧化酶（PPO）的抑制活性和不同提取物的铜螯合特性。乌草叶提取物（SLE）显示出较高的PPO抑制活性和铜螯合能力（p<0.05）。基于LC-MS,山奈酚-3-O-rutinoside被确定为最丰富的化合物，其次是儿茶素和新胆酸。与1.25％焦亚硫酸钠（SMS）处理的样品相比，在4°C冷藏储存12天期间评估了不同水平（0.25-1％）的SLE抑制黑色素沉着和保持太平洋白虾品质的功效。1％的SLE可有效延缓黑色素沉着和细菌生长，其中总活菌计数在12天内不超过微生物限度。此外,1%SLE治疗阻碍自溶，减少蛋白质降解和分解，和最小化的脂质氧化，正如pH值升高较低所见证的那样，TVB-N,TBARS值感官评估表明，与对照和其他样品相比，SLE-1％和SMS-1.25％虾的相似性得分和总体可接受性更高。因此,SLE可用作天然替代品，可有效降低冷藏过程中虾的黑变病和品质损失。
