Investigation of the effect of sucrose particle size on the texture, water activity and sensory properties in milk chocolate and compound chocolate

In this study, the effect of using various amounts of sugar particle size with ball mill technique on some physical (texture, particle size, color), chemical (water activity, moisture) and sensory properties of chocolate was investigated and the contribution of sugar particle size to chocolate industry was evaluated. For this aim, two different sugar forms (granulated sugar (T), average particle size (D90) 0.6-1.0 mm, powdered sugar (P), average particle size 0.005-0.1 mm) were used. Chocolate type 2 levels (milk chocolate and compound chocolate) and granulated sugar (T) and powdered sugar (P) rates were studied as 5 levels (T:P; 0:100, 25:75, 50:50, 75:25 and 100:0). The number of replicates for each trial was 3. The total number of trials (n) was determined as 2*5*3=30. The obtained chocolate samples were kept for 28 days at room temperature (20°C) and the temperature representing the extreme conditions (30°C) and the analysis were carried out in 7-day periods; the effect of temperature and time on some chocolate quality parameters was also determined. In this study, texture (hardness; penetration technique), water activity, sensory properties (multiple comparison test), particle size (with micrometer technique), color (CIE-Lab method) and moisture content of samples were investigated. ANOVA (one-way analysis of variance) and Tukey's test were used for statistical analysis and the significance of the difference between the samples was determined. The use of sucrose particle size in different proportions significantly influenced some quality parameters. In general, the use of 100% powdered sugar form in the samples shown better results on water activity, color, hardness and sensory properties. With the decrease of sugar particle, the product showed a more homogenous, well-packaged; moisture, hardness and water activity differed between samples due to the change in fat content. Reduction of particle particle size increased sensory sweetness perception in milk chocolate and compound chocolate and the samples in 100% crystalline form had the lowest brightness (P˃0.05).