The influence of conching time on the sensory profile and consumer acceptance of milk chocolates enriched with freeze-dried blueberry (Vaccinium spp.)

Abstract

Conching is a processing stage of industrial chocolate manufacture that is essential to the development of the sensory and rheological properties of the finished product. It promotes the physicochemical changes leading to flavor, aroma, and flowability refinement by continuously heating, aerating, shearing, and homogenizing chocolate mass during an extended time length. Conching duration is a key processing parameter that depends on the type of chocolate, the quality of primary ingredients, the conche's configuration, and the desired sensory outcome in the chocolate. Shorter cycles are often beneficial to manufacturers, due to increased productivity and reduced energy consumption, but they may be insufficient to fully develop chocolate's desired sensory properties. The present study aimed to shed light on the trade-off between product quality and process efficiency by assessing if varying conching durations were associated with statistically significant differences in the sensory profile and consumer acceptance of milk chocolates with freeze-dried blueberry. Samples were produced under an alternative method of conching prior to ball mill refining, with times investigated being 6, 12, 24, 36, 48, and 72 h, and were subsequently submitted to Quantitative Descriptive Analysis and consumer acceptance test. No statistically significant differences in either sensory profiles or consumer acceptance ratings of samples were observed, with the exception of hedonic values for aroma, indicating that a 6-h conching cycle was already enough to develop the sensory properties of the milk chocolate with freeze-dried blueberry. The feasibility of shorter conching times suggests a potential for energy saving and increased productivity in the production of milk chocolates following the conching prior to ball mill refining concept.