摘要:
为研究天然的防腐保鲜剂ε-聚赖氨酸对牡蛎防腐抗菌效果,使用浓度为0.2%和2%的ε-聚赖氨酸浸润处理牡蛎,通过监测(4±1)℃贮藏过程中牡蛎的菌落总数、pH、挥发性盐基氮(TVB-N)含量、TPA质构和氨基酸组成,评价贮藏期间的牡蛎品质变化。结果表明,ε-聚赖氨酸对牡蛎有很好的防腐抗菌效果。2%的ε-聚赖氨酸的抑菌效果更为显著,贮藏第5 d,与空白组相比,菌落数至少低1个数量级,TVB-N值小3.59 mg/100 g,差异极显著(P<0.01)。而在贮藏的10~13 d,空白组与高浓度组牡蛎的pH、TPA和FAA这三项检测指标间差异显著(P<0.05),其中,2%的ε-聚赖氨酸组硬度增加极显著(P<0.01)。此外,2%ε-聚赖氨酸组的Glu和Gly含量在贮藏10 d后变化平缓,较之空白组差异显著(P<0.05)。贮藏19 d,FAA总量比空白组低16.98 mg/g,差异极显著(P<0.01)。ε-聚赖氨酸能抑制牡蛎微生物增殖,延缓牡蛎腐败进程,表明ε-聚赖氨酸用于水产品生物防腐剂的研发有潜在的应用价值。
Abstract:
To study the antiseptic and antimicrobial effect of natural biopreservative ε-polylysine,oysters stored at(4±1) ℃ were treated with two concentrations of ε-polylysine(0.2% and 2%). By monitoring the total bacterial counts,pH,total volatile base nitrogen(TVB-N),texture profile analysis,and free amino acids compositions during storage,the quality of oysters were evaluated. ε-polylysine showed potential antiseptic and antimicrobial effects on oysters in this study. Compared with blank group,2% ε-polylysine could significantly reduce the number of colonies by at least one order of magnitude at the first 5 days of the preservation process,as while as the value of the TVB-N decreased by 3.59 mg/100 g(P<0.01). Otherwise,the obvious differences appeared at three indicators,containing pH,TPA and FAA from the 10th to 13th day because of 2% ε-polylysine(P<0.05),especially at hardness with extremly significant increasing(P<0.01). Moreover,the contents of Glu and Gly changed gently after the 10th day in the 2% ε-polylysine group,which was significantly different from the blank group(P<0.05).At the 19th day,the FAA was lower than that of the blank group for 16.98 mg/g(P<0.01). The results showed that ε-polylysine could inhibit the proliferation of microbes and delay the oyster decay,which indicated ε-polylysine had potential application for the development of biopreservatives for the aquatic products.
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