Abstract: Antibacterial characteristics of ethanol extracts from peanut,chestnut and sunflower hulls on the contamination bacteria of six common foods were studied by filter paper methods. Changing of antimicrobial activity,thermal stability of the extracts and their preservation effects on foods were also studied under different pH values. The results showed that there are observable antibacterial effects of the three extracts on six tested bacteria. The antibacterial effects are affected markedly by pH value. And there are exceedingly good thermal stability of antibacterial activities. Food preservation experiments showed that the antibacterial rates of the tested foods all are over 80%,and the maximum rate is 94.20%.

Key words: nut food, nut hull, ethanol extract, antimicrobial characteristics