Effect of Drying Temperature and Type of Carriers on the Physicochemical Properties of Spray Dried Mulberry Powders

The effect of drying temperature and type of carriers on the performance of mulberry juice during spray drying was investigated and the optimum parameters of mulberry juice during spray drying were also achieved. The results showed that powder recovery(R_p),water activity(a_w),water solubility index(WSI),total phenol content(TPC)and free radicals scavenging capacity decreased with increasing of inlet temperature. With the increasing of outlet temperature,R_p gradually increased,while a_w,TPC,and free radicals scavenging capacity decreased. However,WSI was not significantly affected. The type and mass fraction of drying carriers in the feed solution had significant effect on the physicochemical properties of spray dried mulberry juice powders. With increasing of inulin mass fraction,R_p gradually decreased,a_w increased,TPC and free radicals scavenging capacity decreased first and then increased. However,WSI was not significantly affected. With increasing of trehalose mass fraction,R_p gradually decreased,a_w,TPC,and free radicals scavenging capacity increased. However,WSI was not significantly affected. With increasing of gum arabic mass fraction,a_w,TPC and free radicals scavenging capacity gradually decreased,while R_p and WSI gradually increased. The optimum parameters of spray drying of mulberry juice were:Inlet temperature 130℃,outlet temperature 75℃,mulberry juice:maltodextrin:whey protein isolate:trehalose total solids mass fraction was 65:8.5:1:25.5.Under these conditions,the recovery rate of mulberry powder was(59.08%±2.86%),the total phenol content was(1209.47±40.37) mg GAE/100 g,and the free radical scavenging capacity was(0.62±0.06) mg/mL.