鲜榨柠檬原汁对7种常见食源性致病菌抑菌效果及被膜形成的影响

Antibacterial activity of Citrus limon and its effects on biofilm formation to seven common foodborne pathogens

目的研究鲜榨柠檬果皮和果肉原汁对7种常见食源性致病菌的抑菌效果以及对生物被膜形成的影响。方法对柠檬果皮和果肉分别榨汁测定总酸;采用顶空取样结合气相色谱-质谱联用技术(GC-MS)分析鲜榨柠檬果皮和果肉原汁中的主要挥发性成分;采用平板抑菌试验研究两种鲜榨原汁的抑菌效果;采用试管法和96孔板法研究两种鲜榨原汁对细菌生物被膜形成的影响。结果鲜榨柠檬果肉原汁总酸为98.86 g/kg,鲜榨柠檬果皮原汁总酸为6.05 g/kg;GC-MS结果表明鲜榨柠檬果皮和果肉原汁中主要挥发性成分以柠檬烯、γ-萜品烯、α-松油醇、柠檬醛等为主;鲜榨柠檬果肉原汁对7种常见食源性致病菌均具有明显抑菌效果,鲜榨柠檬果皮原汁均未出现明显抑菌作用;鲜榨柠檬果肉原汁对部分细菌被膜形成有抑制作用,鲜榨柠檬果皮原汁对部分细菌被膜形成有明显促进作用。结论鲜榨柠檬原汁对常见食源性致病菌生长及被膜形成影响的研究为食源性致病菌的防控提供了科学依据。

Objective To explore the antibacterial activity of lemon peel and pulp fresh juice against seven common foodborne pathogens and its effects on bacteria biofilm formation. Methods The fresh lemon peel and pulp juice were prepared by juice extractor. The total acids of fresh lemon peel and pulp juice were determined. Volatile compounds of lemon peel and pulp fresh juice were extracted by headspace sampling and the extracts were detected by gas chromatography-mass spectroscopy（ GC-MS）. The antibacterial tests of lemon peel and pulp fresh juice were examined on tryptic soy agar（ TSA）. The bacteria biofilm formations were tested by tube method and 96-well method. Results The total acids were 98. 86 g / kg for pulp fresh juice,and 6. 05 g / kg for peel fresh juice,respectively. GC-MS analysis showed limonene,γ-terpinene,α-terpineol and citral were the main volatile compounds in lemon peel and pulp fresh juice. The growths of seven target pathogens on TSA were inhibited distinctly by lemon pulp juice and did not affect by lemon peel juice. The tube and 96-well methods for the bacterial biofilm formation tests showed that the lemon pulp juice had obvious inhibition to several bacteria biofilm formation,and lemon peel juice had obvious promoting effects to most bacteria biofilm formation. Conclusion The effects of lemon juice on common foodborne pathogens and their biofilm formation provide meaningful scientific data for the prevention and control of foodborne pathogens.