2.2. Experimental set up
An unstirred batch and a cross flow ultrafiltration processes were used separately for clarification of Reb-A from stevia extract.
2.2.1. Unstirred batch set up
The batch cell set up with a capacity of 400 mL, made of stainless steel, was consisted of two matching flanges with an internal groove and a cylindrical vessel of inner diameter of 78 mm. Circular flat sheet membrane was placed over an aluminium grid base on the lower flange to provide mechanical support. The two flanges and the cylinder were tightened and leak proofed using two rubber gaskets. The effective membrane area was 35.27 square cm. The feed was poured through the feed inlet and permeate was collected from the bottom of the lower flange. Air pressure was maintained from a compressor (Matrix, AC 20–50) with adjustable pressure control valve. The schematic diagram of the batch cell is shown in Fig. S1 (in Supplementary material).