Oily, low water activity (OL aw) products including tahini (sesame seed paste), halva (tahini halva), peanut butter, and chocolate, have been recently linked to numerous foodborne illness outbreaks and recalls. This review discusses the ingredients used and processing of OL aw products with a view to provide greater understanding of the routes of their contamination with foodborne pathogens and factors influencing pathogen persistence in these foods. Adequate heat treatment during processing may eliminate bacterial pathogens from OL aw foods; however, post-processing contamination commonly occurs. Once these products are contaminated, their high fat and sugar content can enhance pathogen survival for long periods. The physiological basis and survival mechanisms used by pathogens in these products are comprehensively discussed here. Foodborne outbreaks and recalls linked to OL aw foods are summarized and it was observed that serotypes of Salmonella enterica were the predominant pathogens causing illnesses. Further, intervention strategies available to control foodborne pathogens such as thermal inactivation, use of natural antimicrobials, irradiation and hydrostatic pressure are assessed for their usefulness to achieve pathogen control and enhance the safety of OL aw foods. Sanitation, hygienic design of manufacturing facilities, good hygienic practices, and environmental monitoring of OL aw food industries were also discussed.

Cross-cultural differences exist in the typical temperature of water served with meals. North American people typically drink iced water/beverages while eating, whereas European or Asian people show a preference for room temperature water or hot water/tea, respectively. It has been reported that food perception and acceptance are influenced by oral temperature, as well as by serving temperature of food. Based on the fact that the iced or hot water served with meals can alter the oral temperature, the present study aimed to determine whether the temperature of served water can affect the sensory perception and acceptance of food subsequently consumed. Following a mouth rinse with water served at 4, 20, and 50°C for 5s, two different types of food, dark chocolate and cheddar cheese, were evaluated in terms of sensory intensity and overall liking. For the dark chocolate, the intensity ratings for sweetness, chocolate flavor, and creaminess were significantly lower when following water at 4°C than when following water at either 20 or 50°C. However, the modulatory effect of water temperature on sensory perception was not obtained with cheddar cheese. In addition, the temperature of served water altered the acceptance for the foods subsequently presented. Specifically, the overall liking for the dark chocolate was significantly lower when following water at 4°C than when following water at either 20 or 50°C. In conclusion, the present study demonstrates new empirical evidence that the consumption of iced water can decrease perceived intensities of sweetness, chocolate flavor, and creaminess for subsequently consumed chocolate. Our findings may provide one of plausible answers to the question of why North American people, who are more used to drinking iced water, show a strong preference for more highly sweetened foods.