Phytosterols in 17 Turkish hazelnut (Corylus avellana L.) cultivars

The phytosterol contents of the oils from 17 Turkish hazelnut cultivars were determined by gas chromatography with a flame ionization detector. The total phytosterol content varied from 1180.4 (Uzunmusa-Ordu) to 2239.4 mg/kg (Cavcava), and the average was 1581.6 +/- 265.1 mg/kg. One of the most significant commercial cultivars, Tombul, contained quite low total phytosterols (1297.7 mg/kg). Total and individual phytosterol contents of hazelnut cultivars were significantly different at p < 0.01, except for phytostanol and campestanol. The main component was beta-sitosterol which ranged from 82.8 to 86.7% in all cultivars. This was followed by campesterol, Delta(5)-avenasterol, sitostanol and stigmasterol. Interestingly, the same cultivars from different regions showed similar total phytosterol contents, and fall almost within the same range according to Duncan's test, which may indicate that the phytosterol content is highly related to the cultivar.