The effects of storage, irradiation, and processing on selected viruses in ground pork

Abstract

Viruses are becoming increasingly recognized as major causes of foodbome diseases. While adequate cooking is a time-tested method of inactivating viral contaminants, the numerous outbreaks of viral foodbome disease indicate that either thorough cooking does not occur or that the foods are contaminated aiter cooking. These studies investigated other methods of inactivating viral contaminants in ground pork and pork products. Storage conditions can be used to decrease viral numbers in pork, but the time needed makes this impractical. At refrigerator (4° C) temperatures, most viruses tested lasted long after the product would be considered spoiled. At home freezer (-20° C) temperatures, many viruses were extremely hardy. Hepatitis A vims survived for one year in the freezer with little loss in titer. Even for those that were inactivated by freezer storage, the time needed for total elimination rendered this method impractical. Viral contaminants in foods can be eliminated by irradiation. However, vimses are substantially smaller targets than bacteria, so a correspondingly larger dosage is needed for inactivation. Currently approved dosages will lower viral numbers but will not inactivate all of the vimses present in foods, unless the viral numbers are quite low. Processing has been shown to adequately inactivate even the most durable of vimses. However, if products are contaminated with vimses after processing, this study indicates that the changes that processing induce in the products will not be efifective in inactivating the vimses. This becomes an important control point especially for those products which are meant to be eaten with no fiirther cooking or processing.