3.2. Enzyme-assisted stevioside extraction
3.2.1. Effect of Incubation time
An incubation period of 45 min was found to be optimum for
hemicellulase (1.0%, w/v)-based extraction of stevioside
(152.00 ± 0.05 lg). However, for pectinase and cellulase, the highest
recovery was achieved in 60 min. Pectinase-assisted extraction
of stevioside (333.28 ± 2.20 lg) was more effective than cellulose-
(128.05 ± 0.05 lg) or hemicellulase- (152 ± 0.05 lg) assisted
extraction (Fig 3). Cellulase and hemicellulase act on cellulose
and cleave beta-1,4 linkages, which are present in the primary wall
beneath the first layer of the middle lamella of the plant cell wall,
and catalyse its breakdown into glucose and cellobiose. A large in-