花生壳分级提取物抑菌活性及其稳定性

本文采用溶剂浸提法分级提取花生壳中有效抑菌成分,通过滤纸片法研究不同提取物对食品中常见的腐败菌和致病菌的抑菌活性,并进一步探究pH、温度、紫外辐射、金属离子对其稳定性的影响。结果表明:花生壳分级提取物对供试菌均有一定的抑制活性,其中乙酸乙酯提取物对金黄色葡萄球菌的抑制作用最强,对金黄色葡萄球菌、大肠杆菌的最低抑制浓度(Minimum inhibitory concentration,MIC)分别为31.25、62.5 mg/mL。稳定性实验表明,花生壳乙酸乙酯提取物的抑菌活性在7 < pH < 10明显降低;20~80℃处理后,其抑菌活性稳定,但过高或过低温度处理(0、100℃),其抑菌活性下降;随着紫外辐射时间的增加,抑菌活性呈下降趋势;金属离子对花生壳乙酸乙酯提取物抑菌作用有所差异,Cu2+、Fe2+、Al3+可增强其抑菌作用,Mg2+、K+、Mn2+可降低其抑菌作用。本实验可为花生壳提取物作为食品天然防腐剂的开发提供依据。

Antibacterial Characteristics and Stability of Fractionated Extracts from Peanut Hull

In this paper,the effective antibacterial components in peanut hull were extracted by solvent extraction method. The antibacterial activity of different extracts on common spoilage bacteria and pathogenic bacteria in food was studied by filter paper method,and the influence of pH,temperature,ultraviolet radiation and metal ions on its stability was explored. The results showed that the peanut hull fraction extract had certain inhibitory activity on the tested bacterias,and the ethyl acetate extract had the strongest inhibitory effect on Staphylococcus aureus,and the minimum inhibitory concentration(MIC)against Staphylococcus aureus and Escherichia coli were 31.25 and 62.5 mg/mL,respectively. The stability experiment showed that the antibacterial activity of the ethyl acetate extract of peanut hull decreased significantly at 7 < pH < 10;after 20~80℃ treatment,the antibacterial activity was stable,but when the treatment was too high or too low(0,100℃),the antibacterial activity decreased. With the increase of UV irradiation time,the antibacterial activity decreased. The antibacterial effect of metal ions on the ethyl acetate extract of peanut shell was different,Cu2+,Fe2+ and Al3+ could enhance its inhibition,Mg2+,K+,Mn2+ could reduce its antibacterial effect. This experiment can provide a basis for the development of peanut shell extract as a natural preservative for food.