Supercritical Technology-Based Date Sugar Powder Production: Process Modeling and Simulation

Spray dried date fruit extract with a maltodextrin/gum arabic binary blend carrier agent system: Process optimization and product quality

Bioactive compounds can be protected from degradation through encapsulation, increasing their bioavailability and shelf life. Spray drying is an advanced encapsulation technique mainly used for the processing of food-based bioactives. In this study, Box-Behnken design (BBD)-based response surface methodology (RSM) was used to study the effects of combined polysaccharide carrier agents and other spray drying parameters on encapsulating date fruit sugars obtained from a supercritical assisted aqueous extraction. The spray drying parameters were set at various levels: Air inlet temperature (150-170 °C), feed flow rate (3-5 mL/min), and carrier agent concentration (30-50 %). Under the optimized conditions (inlet temperature of 170 °C, the feed flow rate of 3 mL/min, and carrier agent concentration of 44 %), a maximum sugar powder yield of 38.62 % with 3.5 % moisture, 18.2 % hygroscopicity and 91.3 % solubility was obtained. The tapped density and particle density of the dried date sugar were estimated as 0.575 g cm-3 and 1.81 g cm-3, respectively, showing its potential for easy storage. In addition, scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis revealed better microstructural stability of the fruit sugar product, which is essential for commercial applications. Thus, the hybrid carrier agent system (maltodextrin and gum arabic) can be considered a potential carrier agent for producing stable date sugar powder with longer shelf-life and desirable characteristics in the food industry.

Modeling Study of a Microbial Spray-Drying Process Based on Real-Time Sampling

The process of microbial spray-drying has inherent defects such as short time, complexity, and non-visualization of particle trajectory. However, there has been a lack of effective methods for real-time sampling, rehydration, and non-destructive storage of dried particles, as well as mathematical modeling of the drying process of yeast particles based on sampling and measurement data. Therefore, firstly, a real-time sampling system was developed which completed real-time sampling, rehydration, and non-destructive storage of spray-dried particles, and realized the real reproduction of the changes of yeast particles in the process of spray drying. The laws that the motion trajectory of microbial particles during spray drying are divided into the first cycle region and the reflux cycle region were concluded, and the partition mechanism was explored. Then, based on the sampling data and the law of heat and mass transfer, a mathematical model of porous media was established to predict the variation of moisture content and rehydration survival rate of dried microbial particles with drying time. Finally, the mathematical model was tested by a microbial spray drying experiment, and the maximum errors between the predicted value and the test value of moisture content and rehydration survival rate were Xmax1=0.027(d.b) and Qvmax1=1.06%, respectively, both were less than 5% which proved the correctness of the mathematical model of porous media and laid a foundation for the study of the damage mechanism of microbial spray drying.