Effect of Drying Conditions on Physicochemical and Antioxidant Properties of V itex agnus-castus Leaves

Abstract

Vitex agnus-castus (Vitex AC) leaves have been used for medicinal purposes for many years. Drying is important to prepare starting materials for further processing, as it is associated with production cost and quality of the materials. Herein, the effects of five different drying conditions on the physical, chemical and antioxidant properties of Vitex AC were evaluated. The results showed that 30% of dried leaves with moisture content of less than 7% could be produced from fresh leaves. Vitex AC leaves dried by freeze and vacuum drying at 65C had higher levels of bioactive compounds as well as higher antioxidant capacity in comparison with other drying conditions, revealing that these drying conditions are more suitable for drying Vitex AC leaves. However, freeze drying is costly and time-consuming; thus, vacuum drying at 65C is suggested for drying the Vitex AC leaves as the starting materials for further processing steps. Practical Applications As drying is an important process to prepare starting materials for further processing steps, it is important to compare different drying methods to identify the most suitable method with low cost and less effect on material quality. The results showed that inappropriate drying conditions resulted in big loss of bioactive compounds and antioxidant capacity. Vacuum drying at 65C was found to be the most suitable method, which can be easily applied for drying Vitex agnus-castus leaves in the industrial scale.