Design of encapsulator device system and investigation of the effects of some parameters

In this study, the encapsulator device system was designed using the magnetic field principle and capsule production was carried out according to the ionic gelation method. Experimental design was carried out using the Response Surface Method/Central Composite Design. Alginate concentration (1-3 w/v), nozzle diameter (0.514-0.838 mm), frequency (500-1000 rpm), distance (40-60 mm), and flow rate (1.0-8.0 mL/min) were used as independent variables. Gallic acid, a widely used phenolic compound, was used as the core material. The properties of the produced capsules such as encapsulation efficiency, production yield, loading capacity, particle diameter, aspect ratio, circularity, sphericity, polydispersity index, span, D10, D50 and D90 value were investigated as dependent variables (responses). Analysis of variance was performed for each dependent variable. The most suitable model was selected according to the model p-value, the lack of fit p-value, the R2, and the adjusted R2 values. As a result of the analyzes, the effects of the studied parameters on the variables related to the capsule core content (encapsulation efficiency, production yield and loading capacity), shape (aspect ratio, circularity, and sphericity), size (particle diameter, D10, D50 and D90 values), and size distribution (polydispersity index and span) were revealed. It was determined that alginate concentration, frequency, distance, and alginate concentration/distance interaction were statistically significant on encapsulation efficiency. It was observed that the encapsulation efficiency value increased with the increase in alginate concentration. It was determined that the encapsulation efficiency value decreased due to the decrease in particle diameter at 750 rpm frequency values. A high correlation was found between particle diameter and encapsulation efficiency values (R = 0.94). It was determined that parameters other than flow rate (alginate concentration, nozzle diameter, frequency, and distance) were more significant on particle shape. It was found that the sphericity value increased with increasing alginate concentration. It is predicted that sphericity will decrease if the alginate concentration exceeds 3% (w/v). It was determined that alginate concentration, nozzle diameter and frequency parameters were effective on size distribution. An increase in the size distribution values was observed when the frequency was around 750 rpm. With this study, the use of magnetic system in ionic gelation encapsulation was studied and the effects of some parameters on the capsule properties were investigated. With the designed magnetic system, small sized and high production capacity capsules can be produced.