Effect of spray drying on phenolic compounds of cranberry juice and their stability during storage

This study investigated the stability of cranberry phenolics after spray drying (185 degrees C) and during storage, and their changes correlated with different wall materials (gum Arabic (GA), maltodextrins (M1, 10-13 DE; M3, 17-20 DE), and blend of GA and M1 (GAM1)). The storage trial was conducted at 4, 25 and 45 degrees C for 12 weeks. The total phenolic content (TPC), proanthocyanins and antioxidant capacity (AOC) increased after spray drying. The GMA1 powder achieved the highest recovery of TPC, anthocyanin (ANC) and AOC. During storage, the phenolics fluctuated and peaked at 8-10 weeks. Phenolic profiles of powders at week 0, 8 and 12 were studied to provide insight into the changes. Nineteen compounds were quantified using HPLC-DAD-MS/MS, with most of them showed great increases at week 8, in particular quercetin (increased up to 16.3 times). The results verified that the increase in TPC was due to decomposition of phenolic polymers. After storage of 12 weeks at 25 degrees C, the phenolic composition remained similar to the initial amount in all powders.