Hazelnut Kernel Size and Industrial Aptitude

Abstract

Kernel size is the main hazelnut quality parameter for the consumption market. However, industrial purposes are the main destination for the main hazelnut cultivars. This work aims to identify industrial aptitude relationships to kernel size, and qualitative nut and kernel traits eligible to enhance hazelnut’s commercial value. The qualitative hazelnut traits of cv “Negret” and “Pauetet” were assessed via in-shell and shelled nut sizes for two years. In-shell hazelnuts were tested for weight, shape, percent kernel, yield and shell thickness. Kernels were measured for shape, weight, roasting aptitude, skin color, moisture content and water activity, free acidity, fat content, crude protein, total sugars, minerals, fatty acid composition, α-tocopherol and oil stability. In-shell hazelnut traits significantly differed between cultivars, sizes and storage period. Shell thickness and nut roundness increased almost linearly with nut caliber, whereas kernel percentage decreased. Kernel roundness increased linearly with caliber. The blanching and roasting aptitude of “Negret” increased linearly with caliber, whereas no significant trend was observed for “Pauetet”. Significant differences between cultivars were confirmed for water activity, oil acidity and skin color. Regarding chemical composition, fat content increased linearly with caliber in both cultivars, and α-tocopherol followed the same trend in “Negret”. The sugar content tended to decrease with caliber, whereas crude protein, fiber and minerals did not show any significant relationship with kernel size. Unsaturated and polyunsaturated fatty acids fitted to linear models related to caliber, showing differences between cultivars. Unsaturated fatty acids increased with caliber, whereas polyunsaturated fatty acids decreased, and the oil stability increased linearly with kernel size. These results show that some hazelnut key traits change significantly with kernel size. The linear models presented could be a powerful tool for the confectionery industry to modulate the industrial value of given hazelnut batches.

Diversity of hazelnut varieties and changes in plant development during introduction in the semi-arid zone

“…The generation of yield depends on many parameters of both the plant itself and its fruit, which has been repeatedly noted above. However, the specific mechanism is sometimes difficult to identify, since depending on the genotype, quite different sets of features can be the key ones (Mehlenbacher & Molnar, 2021;Romero-Aroca et al, 2021;Taghavi et al, 2022). The key features for each of the varieties have been specified in this study (Yao et al, 2008;Valeriano et al, 2022).…”

Effects of UV-B Radiation on the Performance, Antioxidant Response and Protective Compounds of Hazelnut Pollen

“…It is generally grown in the northern hemisphere of the world; Turkey, Italy and Azerbaijan are the main producers of hazelnuts [ 2 ]. The demand for hazelnuts in the chocolate and confectionery industry, the main users of hazelnuts, is increasing progressively [ 3 ]. Parallel to the increase in demand, studies to improve the production of hazelnuts with the aim of investigating in depth the factors that influence the product yield are becoming increasingly demanding [ 4 ].…”