The fat content increased significantly from 7.41 to 8.73 g/100 g dry
matter after fermentation. The fat content had decreased initially fromdays 0 to 2 before increasing subsequently (Fig. 1A). Y. lipolytica
produces a few extracellular and cell wall-bound lipases (Fickers et al.,
2011). These lipases become active at the growth phase, increase rapidly
at the start of stationary phase and peak at late stationary phase
(Papanikolaou and Aggelis, 2003). Itwas reported thatwhen Y. lipolytica
was cultivated in rapeseed oil without glucose supplementation, extracellular
lipase activity increased immediately and remained high
throughout fermentation (Kamzolova et al., 2011). Similarly, in this
study, as the autoclaved okara contained a greater amount of fat but
no glucose, a high initial level of extracellular lipase activity was likely.