壳聚糖对食品常见菌的影响研究

A study on the effect of chitosan on common bacteria in food

实验用85%和95%脱乙酰度两种壳聚糖,通过滤纸片药液浸泡法和液体培养分光光度法(青霉是测量菌丝浓度)对食品中常见的三种不同类别的菌(大肠杆菌、酵母菌、青霉菌)进行测定,经分析得出:用同一种壳聚糖对同一菌种,随着壳聚糖药液浓度的增大,其抑菌效果也越来越强;相同浓度的壳聚糖药液对不同的菌种有不同的抑菌效果,抑菌效果由强到弱依次是啤酒酵母、大肠杆菌、青霉菌;两种脱乙酰度的壳聚糖对大肠杆菌抑菌圈测定结果差别不大(P﹥0.05)。液体培养分光光度法在壳聚糖浓度为0.002%和0.006%时,有显著性差异(P﹤0.05)。两种脱乙酰度的壳聚糖对酵母菌和青霉菌抑菌性差别不大(P﹥0.05)。85%脱乙酰度的壳聚糖比95%脱乙酰度的壳聚糖抑菌性略强。

In the experiments,three types of bacteria commonly found in food(escherichia coli,yeast and penicillium)were measured in the presence of two kinds of chitosan with deacetylation degrees being 85%and 95%by filter paper immersion method and liquid culture spectrophotometry(the concentration of mycelia is measured for penicillium).The results showed that an increase in the concentration of chitosan leads to a stronger antibacterial capacity when the kind of chitosan and type of bacteria are both specified.With a given concentration of chitosan,antibacterial capacities for the three bacteria are different,i.e.,beer yeast>escherichia coli>penicillium.As for escherichia coli,the difference between the two kinds of chitosan in terms of antibacterial capacity is found to be minor because of(P>0.05).Under conditions of chitosan concentrations being 0.002%and 0.006%,the results by liquid culture spectrophotometry show significant difference(P<0.05).Although the difference between the two kinds of chitosan for inhibiting yeast or penicillium is minor(P>0.05),the antibacterial capacity of chitosan with 85%deacetylation degree is slightly stronger than that of chitosan with 95%deacetylation degree.