Inulin–whey protein as efficient vehicle carrier system for chlorophyll: Optimization, characterization, and functional food application

Natural chlorophylls mostly found in vegetables such as spinach (Spinacia oleracea) could be employed as a possible substitute for synthetic colorants because of their intense green properties. However, the stability of natural chlorophyll is a major challenge to its utilization in the food industry. In this study, spray drying as an encapsulation technique was used to improve the stability of natural chlorophyll. Box–Behnken design was utilized to optimize the spray drying conditions for chlorophyll. Optimum conditions were given as inlet temperature, 132°C; inulin‐to‐whey protein isolate ratio, 61%:39%; pump rate, 25%, resulting in 92.3% encapsulation efficiency, 69.4% solubility, and −13.5 mV zeta potential at a desirability level of 0.901. The particle size, Carr index, bulk and tapped density, polydispersity index, and color showed satisfactory results. Crystallinity, endothermic peak melting temperature, and the enthalpy of chlorophyll‐loaded microcapsules increased when compared to the blank microcapsules suggesting decreased hygroscopicity and enhanced thermal stability. In addition, the suitability of fabricated microcapsules using yogurt as a food model was assessed. Yogurt incorporated with chlorophyll‐loaded microcapsules showed no significant pH modification with better apparent viscosity than control and sodium copper chlorophyllin (SCC) yogurt after 9 days of refrigerated storage. Based on the studied responses, the spray drying process could be optimized to achieve optimal output and product quality. Practical Application Spray drying is a cheap and convenient approach for microencapsulating bioactive compounds such as chlorophyll. However, the physico‐chemical and functional properties of the spray‐dried microcapsules are influenced by operating conditions, such as inlet temperature, type and concentration of wall materials, and feed flow rate. Therefore, to maximize and obtain a superior quality of the final product, there is a need to optimize the spray drying process. The Box–Behnken design employed in this study could be utilized as an appropriate technique to design, enhance, and develop process parameters for the fabrication and better retention of the physico‐chemical properties of spray‐dried chlorophyll microcapsules.