Development of chewy candy process by ultrasound-assisted crystallization

In this study, it was aimed to develop an innovative process using ultrasound (US) assisted crystallization (sonocrystallization) as an alternative to a process in the conventional chewy soft confectionery production that aims to complete the partial crystallization of sucrose and has a critical importance on the quality properties of the final product. For this purpose, activities for US assisted crystallization and crystal development process optimization were conducted, and the obtained products were investigated in terms of color, moisture content, water activity, texture profile analysis, sensory analysis, glass transition temperature, viscoelastic properties, and microstructure. In the first phase of this study, sample preparation and analysis studies were carried out for the application of US-assisted crystallization to the toffee dough after the pulling process at 60°C, which is the temperature at which the crystallization takes place in industrial toffee-type soft confectionery, for different times (1, 5, 10, 15, and 20 min) and different powers [1000 mA (220 Watt), 1600 mA (352 Watt) ve 2400 mA (528 Watt)]. The results showed that with an increase in the ultrasonic power input, i.e., increasing the current and time, a higher hardness was obtained and products with better sensorial properties were produced. Consequently, the optimum processing conditions for this stage were found to be 20 min sonocrystallization at 60°C with 352 or 528 W power input. In the second phase of the study, the toffee-type confectionery doughs were sonocrystallized taking into account the optimum parameters of the previous stage (352 and 528 Watt, 20 min, 60°C), and the optimum crystal development conditions were determined by keeping them at different times (0, 2, 4, 6, 8, and 10 minutes) and temperatures (60, 65, and 70°C) for crystal development. Then, the samples were fed into the extruder and the toffee samples were prepared. The analysis results of the samples showed that the targets of the study were achieved by subjecting the samples to sonication for 20 min at 528 W (2400 mA) and keeping the samples at 70°C for 8 minutes for crystal development. In conclusion, a unique sonocrystallization process with high repeatability and applicable under controlled conditions, in which the total processing time is reduced by at least 76.7%, with deviations of up to a maximum of ±10% occuring in key quality characteristics compared to control group (sensory, moisture content, color, water activity, and texture profile analysis), was developed for the production of chewy soft candy.