Effect of thermal processing on the phenolic profiles, antioxidant capacity, and volatile compounds of fig wines

Abstract

No systematic studies have been conducted on the manufacture and quality control of fig wines. In the present work, the effect of thermal processing on phytochemical profiles, antioxidant capacity, and volatile compounds of fig wines was investigated. The results show that varieties of detected volatiles and the content of anthocyanins in fig wines decreased significantly owing to fig drying, while individual phenolic concentration increased. The drying process exhibited no significant effect on the contents of total polyphenols and flavonoids, 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) and oxygen radical-scavenging capacities, whereas prefermentation heating showed a negative effect on the antioxidant capacity and phenolic compositions, and resulted in a significant decrease of the contents of acetaldehyde and acetoin. Overall, fig drying showed a stronger effect on the flavor profile of fig wines compared with prefermentation heating. Choosing an appropriate thermal processing procedure is essential to preserve the antioxidant capacity and flavor of fig wines. Practical applications Figs are sodium-, fat-, and cholesterol- free, while they are rich in fibers and antioxidants compounds. Our previous study indicates that figs are excellent raw materials for winemaking attributing to their high sugar and polyphenol contents. At present, there is a lack of studies on systematical investigation of the manufacture and the quality control of fig wines. The phytochemical compounds, antioxidant capacity, and volatiles in fig wines as well as the effect of thermal processing during prefermentation were investigated in this study. We expect our study will provide guidance for producing innovative and high quality products in the wine industry. In addition, we hope it could bring huge economic benefits to smallholder farmers and agricultural cooperatives in fig cultivation.