黄绿卷毛菇胞外多糖对南美白对虾冷藏期间品质的影响

Effect of Extracellular Polysaccharides of Floccularia luteovirens on the Quality of Pacific White Shrimp during Refrigeration

真菌胞外多糖具有丰富的生物活性,其应用是天然多糖开发研究的热点。因此,该文以黄绿卷毛菇胞外多糖(Floccularia luteovirens exopolysaccharides,FEPS)为研究对象,测定其最低抑菌浓度与酪氨酸酶活性抑制能力,并探究复合溶液中真菌多糖浓度对南美白对虾4℃下冷藏品质的影响。结果表明:黄绿卷毛菇胞外多糖对大肠杆菌的最低抑菌浓度(minimum inhibitory concentration,MIC)为2.00 g/L,胞外多糖对酪氨酸酶活性具有一定的抑制作用,在1.5 g/L时对酪氨酸酶单酚酶和双酚酶的抑制率达到(47.67±0.49)%和(44.04±0.21)%。在南美白对虾贮藏中后期(3~12 d),1.0 g/L多糖复合液处理组在黑变程度、色泽、感官评分、挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量、2-硫代巴比妥酸(thiobarbituric acid,TBA)值和菌落总数等方面,均优于其他处理组。综上,黄绿卷毛菇胞外多糖和普鲁兰多糖对南美白对虾保鲜具有协同作用,1.0 g/L多糖复合液可有效延缓南美白对虾品质的劣变速率,可将保质期延长至9 d。

Fungal extracellular polysaccharides possess rich biological activities,making them a focal point in the study of natural polysaccharides.In this study,the extracellular polysaccharides from Floccularia luteovi-rens(FEPS)were studied to determine the minimum inhibitory concentration(MIC)and their inhibitory effect on tyrosinase activity,and the effect of fungal polysaccharide concentration in the composite solution on the quality of Pacific white shrimp(Penaeus vannamei)under refrigeration at 4℃was investigated.The results in-dicated that the MIC of FEPS against Escherichia coli is 2.0 g/L.The extracellular polysaccharides and certain inhibitory effect on tyrosinase activity,and the inhibition rates of tyrosinase monophenolase and biphenolase reached(47.67±0.49)%and(44.04±0.21)%at 1.5 g/L,respectively.During the middle and later stages of storage(3-12 d)of Pacific white shrimp,the group treated with 1.0 g/L FEPS composite solution outperformed other treatment groups in terms of melanosis degree,color quality,sensory scores,total volatile basic nitrogen(TVB-N)content,thiobarbituric acid(TBA)value,and total colony count.In summary,FEPS and the pullu-lan had synergistic effects on shrimp preservation,and 1.0 g/L FEPS-pullulan composite solution was able to inhibit the rate of quality deterioration of shrimp effectively,extending the shelf life to 9 d.