Quality parameters of sunflower oil and palm olein during multiple frying

Abstract

The refined sunflower and palm oils are used in the food industry for the production of fried potatoes. Literary data have shown that palm oil had less tendency to degradation than sunflower oil due to its fatty acid composition. However, palm olein is a palm oil fraction and therefore has a different composition of fatty acids. The aim of this study was to investigate the quality of the refined palm olein in relation to the refined linoleic type sunflower oil during the production of fried potatoes. The oil samples were used for multiple frying during the seven days (40 minutes per day at a temperature of 165o C). The peroxide value and free fatty acid content (acid value) were determined by standard analytical methods. The results showed that the peroxide value in sunflower oil and palm olein increased by 75.0% and 77.8%, while the acid value increased by 50.0% and 26.8%, respectively, in relation to their initial values in the fresh oil samples. Based on these results, it can be concluded that the palm olein was more suitable for frying. However, this finding cannot be reported with certainty because the quality of the oil depends on many more parameters, not only on those analysed in this paper.

U prehrambenoj industriji se za proizvodnju prženog krompira koriste rafinisano suncokretovo i palmino ulje. Prema literaturnim podacima, palmino ulje ima manju sklonost ka degradacionim promenama u odnosu na suncokretovo ulje, zahvaljujući sastavu masnih kiselina. Međutim, palmin olein je frakcija palminog ulja i samim tim ima drugačiji sastav masnih kiselina. Cilj ovog rada bio je da se ispita kvalitet rafinisanog palminog oleina u odnosu na rafinisano suncokretovo ulje tokom proizvodnje prženog krompira. Uzorci ulja su korišćeni za višestruko prženje tokom sedam dana (po 40 minuta svakog dana, na temperaturi od 165o C). Peroksidni broj i sadržaj slobodnih masnih kiselina (kiselinski broj) određeni su standardnim analitičkim metodama. Rezultati su pokazali da se peroksidni broj u suncokretovom ulju i palminom oleinu povećao 75,0% odnosno 77,8%, dok se kiselinski broj povećao 50,0% odnosno 26,8%, u odnosu na početne vrednosti u uzorcima svežeg ulja. Na osnovu ovih rezultata može se zaključiti da je palmin olein pogodniji za prženje. Međutim, ovaj zaključak se ne može navesti sa sigurnošću jer kvalitet ulja zavisi od mnogo više parametara, a ne samo od onih analiziranih u ovom radu.