Bioactive and Physicochemical Properties of Persimmon as Affected by Drying Methods

Abstract

In this study, the effects of three different drying methods (freeze drying, oven drying, and vacuum oven drying) on bioactive (total phenolics, total flavonoids, condensed tannin and total hydrolyzable tannin contents, antiradical activity, and antidiabetic activity) and some physicochemical (dry matter, ash, water activity (a _w ), color, protein, hydroxymethylfurfural, glucose and fructose content) properties of persimmon fruit were investigated. Simplex lattice mixture design methodology was applied to determine the best solvent mixture for the extraction of phenolics from the samples. It was found that the mixture of acetone:water at the ratio of 50:50 % (v/v) was the best solvent mixture for the extraction. The persimmon powder sample obtained from freeze drying showed significantly (p <0.05) higher bioactivity values than oven- and vacuum-oven-dried samples. Antiradical activity changed significantly depending on the drying method employed and it was superior in freeze-dried samples than that of the other drying methods.

Keywords:

• Antidiabetic
• Bioactivity
• Drying
• Hydroxymethyl- furfural
• Persimmon

Notes

X₁: Methanol;

X₂: Acetone;

X₃: Water.

^a FD: Freeze dried; VOD: Vacuum oven dried; OD: Oven dried

Different superscript letters indicate the statistical differences in the same column (p < 0.05)

–: Not determined.

^a X ₁: methanol; X ₂: acetone; X ₃: water

^b SS, sum of squares

^c DF, degrees of freedom

^d MS, mean square

^e R ², coefficient of determination

^f Adjusted R ²

^g Predicted R ².