4种粽叶多酚提取物对草鱼片的保鲜效果

Fresh-Keeping Effect of Polyphenol Extracts of Four Kinds of Leaves for Wrapping Traditional Rice Dumplings on Grass Carp Slices

该文比较荷叶、箬叶、芦苇叶、槲叶4种常见粽叶材料的多酚提取物对草鱼片的保鲜效果,测定冷藏期内生鱼片菌落总数、pH值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、硫代巴比妥酸(thiobarbituric acid,TBA)值,并评定感官指标。结果表明,4种粽叶提取物可有效抑制鱼肉中的微生物生长,使pH值升高延缓2 d、TVB-N限量值延迟2 d以上出现,并可有效延缓TBA值上升,提高浓度能进一步增强保鲜效果。荷叶提取物的抑菌与抑制TVB-N效果明显高于其他粽叶,且荷叶、芦苇叶提取物的作用与天然抗菌剂壳聚糖、溶菌酶相近。荷叶、芦苇叶提取物延缓TBA值上升效果较佳,且荷叶提取物的作用高于壳聚糖、溶菌酶。荷叶提取物对鱼片气味、质地的改善最佳,显著优于壳聚糖、溶菌酶,芦苇叶提取物的效果与壳聚糖接近,4种粽叶提取物对鱼片颜色的改善不及壳聚糖、溶菌酶。4种粽叶可有效延长鱼肉保质期。

The paper aimed to compare the fresh-keeping effect of polyphenol extracts of lotus leaf,indocalamus leaf,reed leaf,and live oak leaf on grass carp slices. The total number of colonies,pH value,total volatile basic nitrogen(TVB-N),and thiobarbituric acid(TBA)of raw grass carp slices during cold storage were measured. The sensory indexes were evaluated. The results showed that the polyphenol extracts of the four kinds of leaves can effectively inhibit the growth of microorganisms in the grass carp. Moreover,with the polyphenol extracts of four kinds of leaves,the rise of the pH occurred 2 d later,and the limit of TVB-N appeared more than 2 d later. In addition,they effectively delayed the rise of TBA value. At higher concentration,the extracts showed stronger fresh-keeping effect. The antibacterial effect and TVB-N-inhibiting effect of lotus leaf extract were significantly stronger than those of the extracts of other leaves,and the effects of lotus leaf and reed leaf extracts were similar to those of natural antibacterial agents,chitosan and lysozyme. Lotus leaf and reed leaf extracts were outstanding in delaying the rise of TBA value,and the inhibitory effect of lotus leaf extract was higher than that of chitosan and lysozyme. Lotus leaf extract was prominent in improving the smell and texture of raw grass carp slices,and the effect was significantly better than that of chitosan and lysozyme. The effect of reed leaf extract was close to that of chitosan. However,the effect of extracts of the four leaves on the color of raw grass carp slices was not as satisfactory as that of chitosan and lysozyme. The four kinds of leaves can effectively prolong the shelf life of fish.