The quality of crude tuna (Thunnus sp.) oil aimed for food-sector-purpose can be
improved by performing purification. The present study was aimed to optimize the
bleaching step during the purification process and determine the optimum variable
conditions using response surface methodology (RSM) in obtaining the lowest oxidation
parameters value to meet the International Fish Oil Standard (IFOS) standard. A total of
five responses including free fatty acids (FFA) value, acid value (AV), peroxide value
(PV), anisidine value (AnV) and total oxidation (Totox) value were studied using central
composite design (CCD), a full factorial design with all combinations of the factors at two
levels (high, +1, and low, −1 level), repeated thrice; applied for two variable factors
(adsorbent concentration [A];% and adsorption time [B]; mins). The optimum model
suggested by the program was a quadratic model for FFA and AnV, and a linear model for
AV, PV and Totox value. The optimum response was reached by the combination of 5%
adsorbent concentration [A] with adsorption time [B] of 20 mins. This formula reduced
the FFA value, AV, PV, AnV, and Totox Value up to 56.57%, 55.36%, 88.86%, 69.69%
and 77.03%, respectively. The purified tuna oil has a clear yellow colour appearance with
a rising percentage of pure fish oil for EPA and DHA of 10.71% and 11.50% from crude
tuna fish oil.
Optimization of mixed base catalyst in the production of Fish oil Biodiesel using Response Surface Methodology (RSM)