Effects of drying temperature on the drying characteristics and volatile profiles of Citrus reticulata Blanco peels under two stages of maturity

• Published in: Drying technology 2022-09, Vol.40 (12), p.2456-2469
• Main Authors: Wang, Jun, Wang, Hui, Xiao, Hong-Wei, Fang, Xiao-Ming, Zhang, Wei-Peng, Ma, Chang-Lu
• Format: Article
• Language: English
• Subjects: Agricultural wastes; antioxidant capacity; Antioxidants; Benzaldehyde; Citrus reticulata peel; Drying; drying kinetics; Environmental impact; fingerprint; Fruits; Gas chromatography; headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS); Ionic mobility; Principal components analysis; Reduction; Spectrometry; Volatile compounds
• ISSN: 0737-3937; 1532-2300
• DOI: 10.1080/07373937.2021.1907590

Citrus peels are considered as an agricultural waste with negative environmental impacts. In the present study, yellow (ripe) and green (unripe) Citrus reticulata peels were dried in a hot air impingement dryer and the effect of drying temperatures (40, 50, 60, and 70 °C) on the drying characteristics, volatile compounds, and antioxidant capacity were explored. The results showed that the drying time of samples was reduced by more than 50% when the drying temperature was increased from 40 to 70 °C. A total of 56 peaks and 29 volatile components were identified by headspace-gas chromatography-ion mobility spectrometry. Drying caused an obvious reduction in the concentration of linalool oxide, benzaldehyde, (E)-2-heptenal, and 1-pentanol, and an increment in the concentration of pentanal, decanal, linalool, and (E)-2-hexenol. Principal component analysis showed that samples under different treatments were clearly distinguished. Drying resulted in a significant reduction of 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power. These findings will contribute to a better understanding of citrus peel drying as well as their volatile profiles and antioxidant capacity changes during drying.