Effects of different drying methods on the physicochemical and functional properties of Pyracantha fortuneana (Maxim.) Li fruit

Abstract

Pyracantha fortuneana (Maxim.) Li fruits (PFFs) are a traditional food with multiple health benefits. Considering the limited information about how drying methods affect chemical and functional properties, this study aimed to determine the effects of hot-air drying (HAD), far-infrared drying (FIRD), vacuum drying (VD), freeze drying (FD), and sun drying (SD) on the appearance, microstructure, and chemical and functional properties of PFFs. Results showed that the qualities changed considerably with different methods. FD fruits had comparable chemicals (phenolics and flavonoids) and bioactivities (antioxidant activities and digestive enzyme-inhibitory effects) to fresh samples. SD and HAD at 40 °C did not trigger serious degradation of bioactivities. Conversely, higher temperatures (60 °C and 80 °C) resulted in remarkable shrinkage and microstructure damage. HAD60, FIRD60, VD60, and HAD80 decreased the contents of free phenolics (by 59.6%, 58.4%, 56.0%, and 61.0%, respectively, P < 0.05) and flavonoids (by 41.8%, 39.8%, 34.7%, and 48.5%, respectively, P < 0.05) compared with the contents in fresh samples. Heat treatment also reduced bioactivities. Principal component and clustering analyses revealed the relationship between samples and properties, indicating that FD, HAD40, and SD preserved chemicals and bioactivities. Generally, the results suggested that the suitable drying technique for PFFs was low-temperature drying.