Optimisation of process parameters to develop nutritionally rich spray-dried honey powder with vitamin C content and antioxidant properties

The aim of present research was to optimise the conditions to develop nutritionally rich honey powder using honey, whey protein concentrate (WPC), aonla (Emblica officinalis. Gaertn) and basil (Ocimum sanctum) extract with the help of co-current spray drier. Response surface methodology was applied to study the effects of inlet temperature (160-180 degrees C), whey protein concentrate (25-35%), feed flow rate (0.08-0.13mLs(-1)), aonla extract (6-8%) and basil extract (6-8%) on product responses, viz. bulk density, hygroscopicity, antioxidant activity (AOA), total phenolic content (TPC) and vitamin C. Statistical analysis revealed that independent variables significantly affected all the responses. The results demonstrated that increasing inlet temperature lowered the bulk density, hygroscopicity, AOA, TPC and vitamin C, whereas addition of aonla extract and basil extract increased the AOA (82.73%), TPC (63.27%) and total vitamin C content (94.89%) as these functional compounds were encapsulated by WPC. Similarly, with increase in feed flow rate and WPC, there was increase and decrease in the bulk density and hygroscopicity, respectively. The recommended optimum spray-drying conditions were inlet air temperature (170 degrees C), feed rate (0.11mLs(-1)), whey protein concentrate (35%), aonla (8%) and basil extract (6%).