Bioactive compounds and fatty acids in hazelnuts (Corylus avellana L.) changes with increasing root age

Key message

As the age of hazelnut orchards increases, the amount of fatty acid composition and bioactive compounds beneficial for health significantly decreases, therefore renewal of old hazelnut orchards is recommended. 

Abstract

This study was carried out to determine how ocak planting age affected bioactive compounds and fatty acid composition in the Tombul hazelnut cultivar. Ocak planting age (20, 30, 40, 50, and 60 years) significantly affected bioactive compounds and fatty acid composition. As ocak planting age increased, total fat, free fatty acids, oleic acid, stearic acid, antioxidant activity, total phenolic and dry matter content decreased. On the other hand, linoleic acid, linolenic acid, and palmitic acid content increased in parallel with the increase in planting age. In addition, the increase in the age of ocak affected the oleic/linoleic acid ratio and caused a decrease in this ratio in 50 and 60 years old ocaks. Correlation analysis showed a high correlation between bioactive compounds and fatty acid composition. According to the results of heatmap clustering analysis, 20, 30, 40, and 50 age groups were clustered together (A), while 60 age groups were clustered in a separate branch (B). Similarly, oil ratio, stearic acid, oleic acid, dry matter content, antioxidant activity, and total phenolic content were categorized as the first group and other components as the second group. As a result, ocak planting age significantly affected the bioactive compounds and fatty acid composition of hazelnut, which are beneficial for human health.