Chemical and Organoleptic Investigations of Hazelnut Irradiated with Multiple Disinfestation Doses

Mira Bogunović*, Branka Katušin-Ražem, Snježana Đurić-Bezmalinović and D. Ražem**

*Fruitgrowing Center, Kačićeva 9, 41000 Zagreb, Croatia
**Rudjer Bošković Institute, P.O.B. 1016, 41000 Zagreb, Croatia

Article history:
Received January 27, 1993
Accepted April 22, 1993

Summary:
Hazelnut suffers considerable loss during storage due to storage pests. In considering disinfestation of hazelnut by irradiation, a relatively high disinfestation dose requirement for Lepidoptera, as compared to Coleoptera, as well as a possible requirement for repeated irradiation, must be taken into account. Chemical and organoleptic properties of irradiated hazelnut kernels were followed as a function of irradiation dose, storage temperature and time after irradiation. Low irradiation doses, up to 5 kGy, did not produce any significant increase of the free fatty acid level, or any decrease of vitamin C. Chemical changes tuere produced in lipophilic components, where an increase with dose of lipid hydroperoxides (up to 240 ppm) and a decrease of a-tocopherol (up to 170 ppm) with increasing irradiation dose were measured. These changes do not result in any detrimental organoleptic properties, as no effects on odor and taste could be detected up to 3 kGy. This means that irradiation of hazelnut with multiple disinfestation doses, up to at least 3 kGy is possible. The fate of radiation-induced free radicals is discussed in terms of the spatial and temporal distribution of radiation chemical events in the lipophilic regions of a hazelnut kernel.