干燥方式对核桃青皮胡桃醌含量与抑菌性能的影响

为考察核桃青皮抑菌活性与干燥方式的关系,以大肠杆菌、金黄色葡萄球菌和石榴干腐病菌为供试菌,评价了自然干燥（P₁）、烘干（P₂）及真空冷冻干燥（P₃）核桃青皮的抑菌活性。结果显示,3种样品对3种供试菌均有较强的抑制作用,并呈现剂量依赖效应,即M₁>M₂>M₃（M₁,M₂,M₃浓度分别为100、80和60 mg/m L的核桃青皮萃取液）,3种干燥方式间比较均表现为P₃>P₂>P₁;P₁、P₂和P₃对大肠杆菌和石榴干腐病菌的最小抑菌浓度（MIC）结果一致,分别为20、15和10 mg/m L,对金黄色葡萄球菌的MIC分别是15、10和5 mg/m L;P₁、P₂和P₃样品中胡桃醌的含量分别是8.04、9.46和11.84 mg/g,与其抑菌活性呈极显著正相关（p<0.01）。表明干燥方式会影响核桃青皮中胡桃醌含量及抑菌活性,其中真空冷冻干燥是一种理想的干燥方式。 

Effects of drying methods on the juglone content and antibacterial activity of green walnut husk

To explore the relationship between dry method and antibacterial activity of green walnut husk, the antibacterial activities of natural drying ( P₁) , hot-air drying ( P₂) and vacuum freeze drying ( P₃) of green walnut husk were evaluated, using Escherichia coli, Staphylococcus aureus and Zythia versoniana Sacc.as test microorganisms in this paper.Results showed that the three samples all had strong inhibition, and presented a dose-response relationship, namely M₁> M₂> M₃ ( dose of walnut green husk extract were respectively 100 ( M₁) , 80 ( M₂) , and 60 ( M₃) mg/m L) .The drying methods were characterized by P₃> P₂>P₁.For P₁, P₂ and P₃, the minimum inhibition concentration ( MIC) of E.coli and Zythia versoniana Sacc.were consistent.The doses were 20, 15 and 10 mg/m L respectively.The MIC of Staphylococcus aureus were 15, 10, and 5 mg/m L.The juglone content of samples were respectively 8.04 ( P₁) , 9.46 ( P₂) , and 11.84 ( P₃) mg/g, significant positive correlation with antibacterial activity ( p < 0.01) .In conclusion, the drying methods could affect the juglone content and antibacterial activity of green walnut husk, vacuum freeze drying was an ideal way.