However, the second pretreatment
results showed that there was no significant change in
the sulfur content values after the first and second pretreatments.
Probably, some amount of sulfur cannot be separated with the
alcohol–water–acid catalyst phase and still it is included in the
ester-initial triglyceride phase. As will be stated in the next section,
the sulfur content of the pretreated chicken fat was decreased to
lower values by transesterification reaction.