Effect of Freeze-Drying and Oven-Drying on Volatiles, Bioactive and Structural Properties of Hawthorn (Crataegus tanacetifolia) Fruit

Authors : Hasene Keskin Çavdar, Eda Adal

Pages : 202-210

Doi:10.24323/akademik-gida.1382905

View : 303 | Download : 252

Publication Date : 2023-10-30

Article Type : Research Paper

Abstract :Hawthorn (Crataegus) fruit, which is traditionally used as a folk medicine, has been commonly used in pharmaceuticals due to its positive neuro- and cardio-selective effects in recent years. Drying is a practical approach for the long-term storage of hawthorn fruits due to their high annual abundance. This study aimed to compare the effects of oven-drying and freeze-drying methods on the quality, bioactivity, volatiles, and surface structure of hawthorn fruits. Total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (IC50) were used to compare the bioactive properties of the fresh and dried fruits. The volatiles of fresh and dried hawthorn fruits were determined by GC-MS. The TPC and TFC of freeze-dried fruit extracts were markedly higher than those of fresh and oven-dried fruit extracts (p<0.05). The IC50 value of the freeze-dried fruit extract was 480 µg/mL, considerably lower than the fresh (530 µg/mL) and oven-dried fruit extracts (500 µg/mL) (p<0.05). Freeze-drying preserved hawthorn fruit color with the highest L* value and the lowest a* and b* color values. Many volatile compounds were identified as esters, aldehydes, hydrocarbon, terpene, etc., and their concentration decreased significantly with oven-drying, in contrast to freeze-drying. Scanning electron microscopy showed that the microstructure of freeze-dried samples was relatively homogenous and more uniform while oven-dried samples were unevenly broken pieces. Consequently, freeze-drying was determined as the best method for the dehydration of hawthorn fruits in terms of the bioactive content and natural color of fruits, and volatile preservation.
Keywords : Alıç, Dondurarak kurutma, Fırında kurutma, Biyoaktif bileşikler, Uçucu maddeler