Effect of gradient concentration pre‐osmotic dehydration on keeping air‐dried apricot antioxidant activity and bioactive compounds

Abstract

Apricot was treated by osmotic dehydration (OD) before air drying to protect its antioxidant activity and bioactive compound. The experiment set up three groups to pretreat apricot by OD in sucrose solution of different concentrations for 12 h in total, among which, OD-1 was permeated in 60% solution for 12 h; OD-2 was permeated in 45% and 60% solution for 6 h. OD-3 was pretreated in 30%, 45%, and 60% solutions for 4 h. After pretreatment, apricots were dried at 60°C until the water loss rate reaching 75%. Results showed water loss rate and solids gained rate in the OD-2 group were the highest and drying time was shortened effectively. Compared with control, all OD samples could maintain higher content of bioactive compounds and antioxidant capacity, and reduce browning. The OD-2 pretreatment dried apricot could retain the edible quality, bioactive substances, and antioxidant capacity to the maximum extent. Novelty impact statement This research was improved according to the traditional processing technology of preserved fruit. In this study, it was found that under the same pretreatment time, the osmotic dehydration pretreatment with second-order gradient concentration could effectively keep apricots' bioactive compounds and antioxidant activity during the drying process.