“Grada de Viseu” is an indigenous hazelnut
variety from Portugal, and it is considered by the producers
as the most important variety in terms of production
and productivity. Therefore, the aim of this study was to
assess the influence of harvest year (2017/2018/2019) and
location of production (Viseu/Faia) on some physical and
chemical properties of the variety “Grada de Viseu,”
namely biometric parameters, colour, true and bulk densities,
texture parameters (hardness and friability), and
chemical composition. The results showed that the fruits
of the samples harvested in 2019 had higher values of
height, width, and thickness. Hazelnuts from 2018 had
a clearer shell, independently of the location of production,
but only the samples from Faia harvested in 2018
had a clearer kernel. As for the texture, the fruits grown in
Viseu harvested in 2018 had a harder shell and was more
resistant to fracture, whereas the sample from 2019 had a
harder kernel. In all cases, fat was the major chemical
component. The sample from 2019 had a water activity
greater than 0.62, meaning that its stability was not guaranteed.
“Grada de Viseu” from Faia in 2018 presented a
higher induction period and, therefore, was the one with
the highest oxidation stability. The year of production
showed to be the best predictor for almost every chemical
and biometric characteristics. In general, it was possible
to verify that harvesting year and geographical location
influence hazelnut characteristics.
