Dynamic changes in volatile and non-volatile flavor compounds in lemon flavedo during freeze-drying and hot-air drying. (1st February 2023)

• Record Type: Journal Article
• Authors: Zhao, Ru; Xiao, Hongwei; Liu, Chunju; Wang, Haiou; Wu, Yulong; Ben, Ailing; Wang, Yaoyao
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 175(2023)
• Publication Date: 2023-02-01
• Subjects: Lemon flavedo -- Freeze-drying -- Hot-air drying -- Volatile flavour compound -- Non-volatile flavour compound; AD hot-air drying -- FD vacuum freeze drying -- IFD integrated freeze-drying -- VF vacuum freezing -- CFD conventional freeze-drying -- CF conventional freezing -- PCA principal component analysis -- HCA hierarchical cluster analysis -- CA cluster analysis; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2023.114510
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: This study investigated the effects of three drying methods, i.e., integrated freeze-drying, conventional freeze-drying, and hot-air drying, on the dynamic changes in volatile and non-volatile flavor compounds in lemon flavedo. Compared with the fresh samples, the three drying methods resulted in significant loss in the types of volatile flavor compounds of the final dried samples ( P < 0.05). Conventional freeze-drying resulted in the highest decrease in volatile compounds, followed by integrated freeze-drying and hot-air drying, however, integrated freeze-drying preserved more volatile flavor types than conventional freeze-drying and hot-air drying. The amount and types of amino acids of the final dried samples were found to be highest in integrated freeze-drying followed by conventional freeze-drying and hot-air drying. The results of correlation analysis indicated positive and negative correlations between various amino acids, soluble sugars, and volatile flavor compounds. These variations in type and content of flavor compounds in lemon flavedo during drying processes may be attributed to physical diffusion of these compounds and biochemical reactions including enzymatic reactions, thermal degradation, Maillard reactions, heating oxidation etc. Highlights: Integrated freeze-drying (IFD) was used as a novel method to dry lemon flavedo. Conventional freeze-drying and hot-air drying were used as comparisons of IFD. Changes in volatile and non-volatile flavor compounds during drying were revealed. IFD preserved more types of volatile compounds than the other two methods. Various amino acids, soluble sugars, and volatiles were closely related during drying.