Impact of different FD-related drying methods on selected quality attributes and volatile compounds of rose flavored yogurt melts

Abstract

Effects of three freeze drying methods including freeze-drying (FD), infrared pulse-spouted freeze-drying (IRPSFD), and microwave pulse-spouted freeze-drying (MPSFD) on physical properties (color, odor, texture, bulk density, and rehydration time), volatile compounds, bioactive compounds (total phenolics and anthocyanins), and antioxidant capacities of rose flavored yogurt melts are evaluated and discussed. FD samples possessed the shortest rehydration time (7.30 sec) and lowest bulk density (0.117 g/cm3). The color analysis showed the MPSFD sample was darker and had higher red coloration than FD and IRPSFD samples. From the PCA and LDA results, the odor of IRPSFD sample was closer to FD sample than MPSFD sample. FD and IRPSFD showed much better retention of volatile compounds in samples than MPSFD. Moreover, IRPSFD samples contributed better product quality over MPSFD and matched to FD samples. Results indicated that IRPSFD may provide an alternative technique for freeze dried rose flavored yogurt melts and many other foods with high-quality characteristics.