Showing papers in "Food Technology in 1997"

Foodborne Disease Significance of Escherichia coli O157:H7 and Other Enterohemorrhagic E. coli

Abstract: New safety recommendations for destroying enterohemorrhagic E. coli (EHEC) include cooking hamburgers thoroughly, incorporating a procedure that kills EHEC in the manufacture of raw fermented sausage, such as salami, and pasteurizing or using an equivalent processing method for apple cider. Public health problems with EHEC are being recognized throughout the world. The need for consumer education on the safe handling of foods has never been more acute.

Virus transmission via food.

Abstract: Viruses are transmitted to humans via foods as a result of direct or indirect contamination of the foods with human faeces. Viruses transmitted by a faecal-oral route are not strongly dependent on foods as vehicles of transmission, but viruses are important among agents of foodborne disease. Vehicles are most often molluscs from contaminated waters, but many other foods are contaminated directly by infected persons. The viruses most often foodborne are the hepatitis A virus and the Norwalk-like gastroenteritis viruses. Detection methods for these viruses in foods are very difficult and costly; the methods are not routine. Indicators that would rapidly and reliably suggest the presence of viral contamination of foods are still being sought. Contamination can be prevented by keeping faeces out of food or by treating vehicles such as water in order to inactivate virus that might be carried to food in this way. Virus cannot multiply in food, but can usually be inactivated by adequate heating. Other methods of inactivating viruses within a food are relatively unreliable, but viruses in water and on exposed surfaces can be inactivated with ultraviolet light or with strong oxidizing agents.

Microbial growth and survival: developments in predictive modeling

Abstract: Abstract Traditionally, microbiologists have attempted to understand food preservation via challenge tests, the differences between the microbiology of the initial and stored product being interpreted by retrospective consideration of the physical and chemical conditions during storage. Such studies are slow, expensive, and are only relevant to the product and conditions tested. Most foods are nutrient-rich, but microbial growth is often determined by a small number of factors e.g. pH, aw, temperature, atmosphere, preservatives, particular organic acids, and only occasionally particular nutrients. Many stable food products are the result of preservative factors acting in combination, but our understanding is poor. The concept of ‘predictive microbiology’ was proposed, with growth responses of microbes of concern in foods modelled with respect to the main controlling factors — initially temperature, pH and water activity. Models relevant to broad categories of foods would reduce greatly the need for ad hoc microbiological examination of new food products and enable predictions of shelf-life and safety via a computerized database, with considerable financial benefit. Initial scepticism that predictions would not be sufficiently accurate are being replaced by optimism because errors of predictions are proving to be no greater than those of microbiological experiments. Modelling is set to play an important role in developing and maintaining a safe and wholesome food supply.