INFLUENCE OF DRYING CONDITIONS ON THE HAZELNUT QUALITY .1. LIPID OXIDATION

The influence of the drying conditions on the oxidation state of the l ipidic fraction in hazelnut (Corylus avellana, L.) has been studied. D ifferent hazelnut quality parameters (acidity index, K-232 index, K-27 0 index and oxidation stability) have been determined in unshelled and shelled hazelnuts dried under six drying air temperatures (30, 40, 50 , 60, 70 and 80 degrees C). The drying experiments were done with forc ed air circulation, and two varieties of hazelnut were investigated, N egret and Pauetet. It has been observed that hydrolytic reactions affe ct dried Negret hazelnut, increasing with drying temperature. Also, dr ying temperatures higher than 50 degrees C favour an increase of the r ate of lipid oxidation in hazelnut, specially in shelled hazelnuts, wi th a decrease of the oxidation stability.