Antimicrobial effect of various combinations of plant extracts

The combined extracts of corni fructus, cinnamon and Chinese chive were use d to evaluate ifs antimicrobial activity on common foodborne micro-organism s, including bacteria, yeasts and moulds. The combined extract (8:1:1, v/v/ v) showed an entire antimicrobial spectrum and outstanding inhibitory effec t. The combined extract was very stable under heat treatment. The inhibitor y effect of the combined extract was greater with more acidic pH values but lowered with increased pH values. With addition of metal ions, the antimic robial activity of the combined extract was slightly affected With addition of food additives, its antimicrobial activity was slightly enhanced, excep t for citric acid. When the combined extract used in food products, the exp ected antimicrobial effect in dumplings, guava juice and green and black te a was observed Conclusively, in addition to be used as seasoning, the combi ned extract is suitable for incorporating in various food products where a naturally antimicrobial additive is desired. (C) 2001 Academic Press.