The Effect of Adding D-tagatose and Lemon Essential Oil on Quality of Chocolate

Chocolate is a popular and widely consumed product in different ages, however, the demand of consumers has increased for healthy chocolate with free or low sugar in recent years. The objective of present research is to substitute the sucrose of chocolate with D-tagatose and lemon essential oil for improving biological functions. The seven formulations of chocolate included distinct percentages of D-tagatose (0, 13, 29 and 47 %) and lemon essential oil (0, 0.1 and 0.2 %). Afterwards, the tests were performed on chocolate treatments such as moisture level, fat, sugar content before and after hydrolysis, color perception, hardness, antioxidant, microbial and sensory evaluations. The results demonstrated that moisture of treatments (except CTL5 containing 47.80 % D-tagatose and 0.1 % lemon essential oil) was noticeably different from the control. A significant difference was observed between the average sugars of treatments before hydrolysis, however, there was no considerable difference in fat levels (33.39 to 33.41 %). The essential oil has led to a reduction in hardness, so CTL6 (including 47.90 % D-tagatose and 0.2 % lemon essential oil) with higher essential oil had a lower hardness (16.61 N). D-tagatose and lemon essential oil had an influence on color features, but antioxidant functions were affected only by essential oil and all treatments were within the standard range in terms of microbial load. In sensory assessment, the overall acceptance score was given to the control (4.96) and CTL5 (4.92). The conclusion of present research introduced CTL5 as the most suitable treatment for production of healthy chocolate.