DRYING CHARACTERISTICS, COLOUR AND PHYTOCHEMICAL CONSTITUENTS OF BRYOPHYLLUM PINNATUM LEAVE: A FUNCTION OF PRETREATMENT AND DRYING METHODS.

Abstract

The impact of three different drying methods (active solar, direct open sun and hot-air cabinet tray drying) and two different treatment methods (perforated and sliced) on drying characteristics, phytochemical constituents and colour of Bryophyllumpinnatum leaves were investigated. Moisture content of the leaves was measured until equilibrium moisture content is reached. The result obtained revealed that hot air cabinet drying method and slicing pretreatment improves the drying rate of Bryophyllumpinnatum leaves more than active solar and open sun drying methods. Active solar drying method and perforated pretreatment had the best Bryophyllumpinnatum leaves phytochemical constituents and colour retention during drying with brightness L*value (39±0.11), greenness a* (-70±0.60), yellowness b* (82±0.31), colour change ΔE* and intensity C (131.61±0.12) and(107.81±0.90). Logarithmic model had the best potential for describing the drying characteristics of both treated and untreated Bryophylliumpinnatum leaves using active solar and cabinet drying method.