CHARACTERISATION OF HAZELNUT VARIETIES BY TEXTURE ANALYSIS

To evaluate suitability for table use, the taste and aroma of the kernel are important but easy shell breaking could also be regarded as a good characteristic. Texture analysis was used to measure shell resistance to breakage. A sample of 30 nuts of three varieties (‘Barcelona’, ‘Ennis’, and ‘Tonda Giffoni’) and three selections (B6, L35 and L39) were analysed on the three fruit dimensions (length, width and thickness). The following texture parameters were measured: hardness, hardness of work done, 1^st fracture deformation, 1^st fracture % deformation and modulus of deformability. On the same fruits, shell thickness, nut and kernel weight and dimensions were also measured. Texture parameters can be successfully used to discriminate hazelnut varieties. Each variety showed the maximum value of hardness and hardness of work done for one of the considered dimensions. 1^st fracture deformation and modulus of deformability gave interesting information about shell rigidity and deformability. Among the morphological characteristics, nut weight, shell thickness and shape index are the most related to texture parameters.