Executive Summary
Low level ionising irradiation can be used as a phytosanitary treatment for insect pest control on fruit and vegetables. FSANZ has previously assessed the safety and nutritional impact of using ionising irradiation for phytosanitary purposes on various tropical fruits as well as tomatoes and capsicums, and found that doses of ≤1 kGy do not present a safety or nutritional risk to Australian and New Zealand consumers. It is expected that in the near future FSANZ will receive a number of applications to irradiate a variety of other fresh fruits and vegetables for quarantine purposes.
The objectives of this review were to:
- assess the impact of phytosanitary doses of irradiation on the nutritional quality of fruit and vegetables by:
o Investigating the natural variability in vitamin levels in a range of fruits and vegetables
o Documenting changes in vitamin composition of fruits and vegetables following irradiation with up to 1 kGy
o Considering the dietary implications of any reduction in vitamin levels following phytosanitary doses of irradiation (up to 1 kGy). - make recommendations to amend data requirements for irradiation of fruits and vegetables.
Extensive natural variation occurs in the nutrient composition of individual fruit and vegetable types. The main sources of variation are cultivar, season, growing location and degree of ripeness. Post-harvest storage and processing also affect nutrient composition. Fruits and vegetables are rich sources of vitamin C and carotenes. Substantial data documents the natural variation in levels of these nutrients, with differences of more than ten-fold being common between cultivars.
Phytosanitary doses of irradiation typically range from 0.15 to 1 kGy. At these doses there is no effect of irradiation on macronutrients or minerals. However, the effect on vitamins is less clear, with vitamins A, C, E and thiamin being most sensitive to irradiation. Fruits and vegetables generally have high levels of carotenes and vitamin C but are not major contributors to intakes of vitamin E or thiamin, therefore this review focused on vitamin C and carotenes. Review of the published literature demonstrated that phytosanitary doses of irradiation:
- had no effect on carotene levels in fruits and vegetables
- did not decrease vitamin C levels in the majority of fruits and vegetables
- had little effect on other non-vitamin bioactive compounds.
In some cultivars of some fruits vitamin C levels decreased following irradiation. However, in the majority of these cases the vitamin C content of irradiated fruit remained within the range of natural variation. In addition, when the effects of these changes were compared to dietary consumption patterns it was evident that these changes were unlikely to impact on dietary vitamin C intakes in Australia and New Zealand. As carotene levels were unaffected by phytosanitary doses of irradiation it can also be concluded that carotene intakes would not be compromised.
From these data it can be concluded that phytosanitary doses of irradiation do not pose a nutritional risk to the Australian and New Zealand populations. It is therefore recommended that the data requirements for applications to irradiate fruits and vegetables can be streamlined to focus on data for vitamin C, with requirements for other nutrients to be determined on a case-by-case basis.
Download the report:
Nutritional impact of phytosanitary irradiation of fruits and vegetables (pdf 866kb)