Enhancement of Drying Efficiency and Analysis of Functional Compounds for Industrialization of Citrus By-Product

Abstract

This study aimed to solve the problem of low drying efficiency because of the stickiness for the industrialization of the citrus by-products (CBPs). Additional information was obtained by analyzing the functional components of CBP pretreated to improve the optimal drying efficiency. For pretreatment before hot air drying, pectinase, cellulase, and viscozyme, which belong to the glycolytic enzymes, were treated to find the optimal enzyme. As a result, the optimal drying conditions were selected as follows: 1) cold thawing, 2) enzyme treatment (viscozyme＋cellulase 1%)-humid chamber (50°C, 95%, and 2 h), and 3) alcohol treatment (4°C and 24 h). This treatment group showed a drying efficiency of more than four times higher than untreated refrigerated CBP. The main components of CBP were detected as narirutin and hesperidin, and the optimal extraction condition was 40% ethanol for 15 min with ultrasound at 80°C. CBP extracted under optimal extraction conditions showed a content of functional components 2.4 times higher than that of the 70% ethanol extract. In addition, CBP pretreated with optimal drying efficiency also showed an improved functional component content. This research can provide basic data for the industrialization and resourceization of CBP.