The CD spectra of commercial bromelain and purified, cryoprotected
bromelain are shown in Fig. 3B. In the far-UV region, both
curves are practically coincident, suggesting that there is no interference interference
in secondary structures during the precipitation process.
The CD spectra of bromelain obtained in this work are comparable
with those reported elsewhere [43,46]. In the aromatic absorption
region (250–320 nm), data not shown, CD curves of the bromelains
are very similar to the spectrum reported earlier by Arroyo-Reyna
et al. [47]. On the other hand, in the far-UV region those authors
observed considerably weaker bands than those shown in this
work.