A Pilot Study of the Microbiological Quality of Culturally Diverse, Ready-to-Eat Foods from Selected Retail Establishments in Melbourne, Australia

Abstract

In recent years, there has been an increasing number of foodborne outbreaks linked to the consumption of culturally diverse foods. This appears to be because of the increasing quantity of culturally diverse foods available and a preference to store these foods, some of which are considered potentially hazardous, at ambient temperature. This practice may contravene temperature requirements defined by the Food Standards Code. A lack of understanding of the hazardous nature of some culturally prepared foods also poses difficulties in applying the Australian food safety legislation by regulators. This pilot study examined the normal microbiota of four culturally diverse foods: nem chua, che dau trang, kueh talam, and bánh tét nhân man, which are traditionally stored and consumed at ambient temperature. Challenge testing was conducted to investigate the ability of these foods to support the growth of foodborne bacterial pathogens. Two of the products (kueh talam and che dau) were found to be microbiologically unsatisfactory because of the high standard plate counts. Challenge testing indicated that kueh talam, che dau, and bánh tét nhân man were able to support the growth of Bacillus cereus, Escherichia coli, Staphylococcus aureus, and Salmonella (1-2 log increases over 6 hours at 25 degrees C), suggesting that these foods may require temperature control during storage. However, nem chua was unable to support the growth of test bacteria, probably because of its acidic nature (pH 4.5), suggesting that ambient storage of this food may be safe. This study provided some preliminary evidence to support the need for further sampling and challenge testing of these products.