30H-9 |
Evaluation of different varieties of raw Turkish hazelnut volatiles by GC/MS, electronic nose and sensory profile analysis |
A. Z. ODABASI1, C. Alasalvar2, N. Demir1, and M. O. Balaban1. (1) Dept. of Food Science & Human Nutrition, Univ. of Florida, PO Box 110370, Gainesville, FL 32611, (2) Dept. of Biological & Food Sciences, Univ. of Lincoln, Brayford Pool, Lincoln, LN6 7TS, United Kingdom Turkey is the main hazelnut producer in the world (550,000 MT/year in 2000, shelled basis). There are 16 varieties of hazelnut cultivated in Turkey, of which 5 are commercial varieties. Besides its economic value and health aspects, hazelnut provides a distinctive flavor in a variety of food products. Therefore, identification of its volatiles could lead to an increased use for hazelnut. The objectives of this research were to 1) ascertain if there were any differences in the volatiles and sensory attributes among commercial Turkish hazelnut varieties, and 2) see if an electronic nose (EN) could discriminate between these varieties. Sun-dried, raw, in-shell hazelnut varieties (Cakildak, Fosa, Mincane, Palaz and Tombul) were procured from Giresun-Turkey. Mass spectra of volatiles were obtained using dynamic headspace analysis / gas chromatography / mass spectrometry (DHA/GC/MS). An EN (12 conducting polymer sensors) was used to take readings at 4 min exposure to the samples. The flavor characteristics of the samples were assessed using sensory analysis. Out of 49 peaks, 40 were tentatively identified as aldehydes, alcohols, ketones, furans, aromatic hydrocarbons and miscellaneous compounds. Differences in volatile compounds among varieties were observed. Discriminant function analysis was performed on the EN data. 100% correct classification of the samples into their respective varieties was observed. Cross-validation resulted in an error of 10%. Significant differences (p<0.05) existed among flavor characteristics (“nutty”, “sweetness”, “oiliness”, “aftertaste”, “fruitiness”, “rancid”, “woodiness” and “creamy”) between some varieties. DHA/GC/MS techniques identified important hazelnut volatile aroma compounds. The EN can also discriminate between the hazelnut varieties. This information could assist in the cultivation programs, processors with food formulations, flavor chemistry and other potential applications.
Session 30H, Quality Assurance
|