ABSTRACT
Since the last decade, there is enhanced interest for the use of Ultrasound for the extraction of the constituents from plant: material. The traditional techniques like maceration, percolation, decoction, etc., are time- and solvent-consuming, and thermolabile constituents are difficult to extract using such conventional methods. This review brings into prominence the importance of extraction for delivering high quality product. The Ultrasonic Assisted Extraction [UAE] technique is a promising technique which is highlighted by increased extraction yield, decreased time and solvent consumption; moreover the thermolabile constituents can be safely extracted. UAE also offers some peculiar advantages, such as inhibiting the extraction of protein and pectin, which improve the sensory quality of the tea beverage. A brief theoretical background of the principles involved and the types of instruments used has been presented. The main parameters like ultrasonic intensity, extraction time, solvent nature and volume, temperature, ultrasonic pulsation and matrix characteristics, etc., which influence the UAE have been discussed. The application of optimization techniques, such as Factorial Design, to UAE has been highlighted, with examples. The potential applications of this technique and its performance vis-a-vis that of classical techniques have been elucidated