Radiation preservation of meat and meat products: A review

The World Health Organisation (WHO) in 1980 clarified the position regarding the medical acceptability of irradiated foods when it said‘…no health hazard results from consuming any food irradiated up to a dose of one megarad (1 Mrad)’. This resulted in renewed interest in irradiation as a cost-effective alternative to traditional preservation methods such as canning and freezing. Thus, radurisation (the application of ionising radiation at a dose level which substantially reduces the microbial population) increases the shelf life of poultry, comminuted meat and meat dishes significantly. Low dose irradiation, or radicidation, eliminates parasites such as Trichinae and cysticerci in pork and, very importantly, salmonella organisms in poultry and red meat. Therefore, irradiation has an important rôle to play in public health protection. High dose irradiation, or radappertisation (‘cold sterilisation’), uses doses in excess of 1 Mrad and is analogous to retorting as understood in the canning industry. However, it can adversely affect quality in producing ‘free radicals’ in high protein foods such as meat. To prevent this, special precautions are necessary, e.g. irradiation is conducted at very low temperatures and the product is usually vacuum packed. A further potential use of irradiation is its ability to reduce the quantity of nitrite necessary in cured meats. This may become of practical significance if legislation further reduces the amount of nitrite permitted in these products.