Technological quality parameters in chocolate spread: hazelnut roasting process

Abstract In chocolate spread with hazelnut highly competitive market, it is very crucial to produce a superior product especially in terms of flavour, aroma, and texture to survive. Hazelnut roasting conditions are very important for the final quality of chocolate spread. At the same time, there is no research on the effects of hazelnut roasting conditions on the product. Therefore, this study aimed to characterise the effect of roasting temperature (125, 150 and 175 °C) and time (12.5 and 25 min) on the physicochemical, textural, rheological and sensory properties of chocolate spread with hazelnut. Therefore, this study aimed to characterize the impact of roasting temperature (125, 150, and 175 °C) and time (12.5 and 25 min) on physicochemical, textural, rheological, and sensory properties of chocolate spread. No difference was found between the water activity, firmness, viscosity, particle size distribution parameters d(0.1), d(0.5), d(0.9), D[3.2], D[4.3] values, shear stress and apparent viscosity values, K coefficient of consistency, linear (τ 1 ) yield stress and characteristic shear rate, colour L*, a*, b* values, sensory colour, appearance, consistency and spreadability scores of chocolate spreads. However, roasting condition was found to be significantly effective on general odour, hazelnut odour, flavour, and hazelnut aroma as well as FTIR spectra ( p < 0.05). Hierarchical Cluster Analysis successfully clustered the samples into 3 different clusters according to their FTIR spectra. Furthermore, while one principal component could distinguish the samples on its own, two principal components provided a significantly clearer visualisation. It was determined that chocolate spread with hazelnut produced by roasting at 175 ºC for 25 min was superior in terms of general odour, hazelnut odour, general flavour, and hazelnut aroma in sensory tests.