Nutritive Value of Persian Hazelnut (Corylus avellana L.) Orchards

Abstract

Hazelnut (Corylus avellna L.) is one of the important nut crops in world. The harvesting of hazelnuts is done either by hand or by manual or mechanical raking of fallen nuts in Iran. Common hazel is widely cultivated for its nuts, including in commercial orchards in Europe, Turkey, and Iran. There are some genotypes of hazelnut in Iran that their growing areas are limited to Gillan, Aredbil, Mazandaran, Golestan, Zanjan and Qazvin Provinces. Varieties, location, composition of soils, usage of fertilizer and irrigation affect the fatty acid, mineral and vitamin composition of hazelnuts, and consequently influence the nutritional value and quality of the product. Therefore, the objective of this study was evaluation of protein, crude fiber, and fatty acids in samples in Tarem and Rudsar County farmlands as two economically important provinces. Samples were collected during the harvest season in 2015 from 10 different distinguished cultivars of trees grown in a replicated trial in an experimental orchard. The chemical and physical properties (crude protein, total fat, crude oil, crude fiber, ash, refractive index) were analyzed according to AOAC methods. In investigation on these two varieties, the highest fatty acid had oleic acid with 85.026% in Rudsar (Gillan) and 83.226% in Tarem samples. Evaluation of 420 hazelnut seedling samples reveals that Rudsar variety samples have more protein, ash and carbohydrate while crude fiber percentage in Tarem variety is more. The results of this research reveals that geographical conditions affect the nutritional value of hazelnut significantly (p <0.05).