Irradiation as a processing aid in NZ

The beneficial uses of the irradiation of foodstuffs include inhibition of sprouting, alterations in maturation rates and insect sterilisation (at doses below 1 kGy), decontamination and shelf-life extension (1-10 kGy) and complete sterilisation (>10 kGy). However, changes in quality can mean that many products are unsuitable for treatment. Whether irradiation is a practical aid to processing depends upon the product, the dose required, storage conditions, other treatments, etc. Recent moves by Codex Alimentarius and the U.S. F.D.A. to allow the radiation processing of foods to stipulated doses have accelerated the commercial use of the process overseas, and caused a re-examination of its potential in New Zealand. At present, foodstuffs in New Zealand can only be irradiated with the express permission of the Minister of Health. An outline is given of the types of irradiation facility that are currently available. In the short term, the major rationale for a food irradiation programme in New Zealand would be as a replacement for chemical fumigants used to control insect pests in fruit and vegetables. It appears likely that the use of such fumigants will be heavily curtailed in the next few years. Decontamination of spices and inhibition of sprouting in potatoes, onions and garlic are other possible uses in the short term. Eventually, uses in the extension of shelf-life of some fruit and vegetables, meat and fish are possible but further research is required before it is established whether any New Zealand products would benefit significantly. Several problems (scientific, economic and social) must be overcome before food irradiation is a worthwhile proposition in New Zealand, and these are discussed briefly. Finally, some preliminary development work by DSIR is reported. This includes the irradiation of codling moth and leafroller species in apples, decontamination of spices and, with the Meat Industry Research Institute of New Zealand, a taste trial on chilled, vacuum packed lamb