Quality changes during spouted bed drying of Pepper‐Rosmarin extract

Abstract

Abstract This study was undertaken in order to evaluate the effects of processing and feed composition variables on the retention of volatile compounds and product properties during spouted bed drying of pepper‐rosmarin extract ( Lippia sidoides Cham.). The product loss on drying, L D , moisture content, X p , water activity, A w , concentration of bioactive markers (flavonoid, T F , polyphenol, T PF and thymol contents, TT), antioxidant activity, IC 50 , powder flow properties, powder morphology and crystalline state were the responses analysed. Processing conditions and feed composition significantly affected the product quality, leading to noticeable changes in the retention of bioactive substances. Results of this study show that the concentration of bioactive markers in the dried product tended to increase with the feed flow rate of the feed composition relative to the maximum dryer evaporation capacity, W s /W max , and conversely with the concentration of drying carriers added to the feed composition. The dried extract showed significant antioxidant activity, although significant losses of bioactive marker compounds ( T F , T PF and TT) were observed in some processing conditions.