Effect of different drying methods on the phenolic and volatile compounds of persimmon (Diospyros kaki L.)

Abstract

Persimmon is a fruit much appreciated for its flavor and aroma, presenting high nutritional value and health-beneficial compounds. As it is a seasonal fruit, developing new products promotes its valorization as well as increasing its consumption, being drying a promising option. The objective of the present work was to produce persimmon powder by freeze drying and spray drying and to verify the effects of these drying methods on the retention of phenolic and volatile compounds of persimmon pulp. Phenolic compounds were analyzed in an liquid chromatograph coupled to a mass spectrometer (LC–MS), and volatile compounds were extracted by the stir bar sorptive extraction (SBSE) technique and analyzed in a gas chromatograph coupled to a mass spectrometer (GC–MS). A total of 15 phenolic compounds were identified among the analyzed samples, highlighting the sample obtained by spray drying (SD) that presented the largest number of phenolic compounds. SBSE-GC–MS analysis resulted in the identification of 81 volatile compounds, with alcohols, aldehydes, ketones and terpenes being the main chemical classes present in persimmon pulp and powders. The use of odor activity value (OAV) data made it possible to select 25 active odor compounds in persimmon pulp and powders, and that the decanal was the major contributor to the aroma of the samples. Among the rehydrated powders, 13 compounds presented higher OAV for the sample obtained by freeze drying with maltodextrin. Thus, we can conclude that the drying methods used were efficient in retaining the phenolic and volatile compounds in the persimmon pulp and that maltodextrin contributed positively to this retention, thus preserving the sensory quality of the pulp and its phenolic compounds.