Combined effects of sodium carbonate pretreatment and hybrid drying methods on the nutritional and antioxidant properties of dried Goji berries

Abstract

Combined effects of sodium carbonate (SC) pretreatment and hybrid drying methods (freeze drying-instant controlled pressure drop drying (FD-ICPDD), hot air drying (HAD-ICPDD) on nutritional and antioxidant properties of Goji berries were investigated. Compared with distilled water pretreatment, SC pretreatment could obtain products with better quality. Goji dried by FD-ICPDD showed better overall quality than that dried by HAD or FD alone. FD-ICPDD products exhibited higher contents of total Lycium barbarum polysaccharide (140 g/kg), total carotenoids (2.4 g/kg) as well as the strongest ABTS.+ radical scavenging activity (57.6 μmol TE/g). FD-ICPDD could be an alternative drying method for processing valuable agro-products. Keywords: sodium carbonate, instant controlled pressure drop drying, nutritional properties, antioxidant activity