INHIBITION OF LISTERIA MONOCYTOGENES AND OTHER BACTERIA BY A PLANT ESSENTIAL OIL (DMC) IN SPANISH SOFT CHEESE

The inhibitory effects of a mixture of plant essential oils (DMC) were tested in culture media and Spanish soft cheese. The minimum inhibitory concentration (MIC) was determined in plate count agar and tryptose broth, with pH adjusted to 6.5, against Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Lactobacillus brevis, Micrococcus luteus, Salmonella cholerasuis, Escherichia coli O157:H7 , Enterobacter cloacae, Pseudomonas aeruginosa and Pseudomonas fluorescens. The mixture of essential oils inhibited all Gram-positive bacteria tested at 40 ppm, but higher concentrations were needed to inhibit Gram-negative bacteria, and no inhibitory effect was found against Ps. fluorescens. The effects of DMC against L. monocytogenes and E. coli O157:H7 were evaluated in Spanish soft cheese (Queso Fresco, pH=6.5) stored at 7C. DMC had a bacteriostatic effect against L. monocytogenes at concentrations of 2500 ppm but was ineffective to control the growth of E. coli O157:H7 .     

CONSUMER FOOD SAFETY CONCERNS AND INTEREST IN PESTICIDE-RELATED INFORMATION

Consumer food safety concerns and interest in pesticide related information was measured by personal interviews with 479 consumers in 14 counties in California. Although concern about pesticide safety was noted by almost half of the respondents, nutritional considerations had the greatest impact on food selection criteria. Of those who volunteered pesticide safety concerns, 15% indicated they sought organic produce and 13% said they avoided or reduced produce purchases. In addition to information about the human health effects of pesticide use, consumers expressed high interest in the environmental effects of pesticide use. Consumers currently use television and newspapers as information sources and prefer these to other sources.