The role of free fatty acids (FFA) on the oxidative stability of four different unrefined red palm oils (RPO) has been investigated. Unrefined red palm oil is a typical African edible oil produced by laborious and traditional methods that heavily affect the final product quality. Physicochemical analysis performed on the RPO samples showed a high FFA content (8.3-14.5%), peroxide values between 2.9 and 10.8 meq O2 per kg and a significant presence of carotenoids (up to 1.6 g kg-1). In order to lower the FFA content, the oil was de-acidified (RPO-D) and the treated product resulted with an improved quality when compared with the untreated oil (RPO-U). The de-acidification route, as well as the reduction of the acidity level, caused a reduction in the UV spectrophotometric indices (K232 and K270) whereas the DOBI index increased and both peroxide and carotenoids amounts were unaffected. Furthermore, the oxidation stability of RPO-U and RPO-D was evaluated using two different experimental approaches: a high-temperature method (Rancimat method) and medium-temperature method (reaction induced by the radical initiator, 2,2′-azobis(2,4-dimethylvaleronitrile)). Both methods unequivocally showed a significant improvement in the resistance to oxidation of RPO-D when compared to RPO-U and confirmed the crucial pro-oxidant effect of FFA on red palm oil.
|Codice identificativo ISI:||WOS:000387427700051|
|Codice identificativo Scopus:||2-s2.0-84994034075|
|Titolo:||Influence of free fatty acid content on the oxidative stability of red palm oil|
|Appare nelle tipologie:||1.1 Articolo in rivista|