THE EFFECTS OF SURFACTANTS ON THE OXIDATION OF SUNFLOWER OIL IN EMULSIONS

Karadag, Ayse (2019) THE EFFECTS OF SURFACTANTS ON THE OXIDATION OF SUNFLOWER OIL IN EMULSIONS. International Journal of Food Technology and Nutrition, 2 (3-4). pp. 20-24. ISSN 2671-3071

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Abstract

Lipid oxidation in O/W emulsions take places mostly at the interface of oil and water, therefore the types and properties of emulsifiers accumulating at the droplet interface have a large effect on the oxidative stability of oils in emulsions. In this study, 5% sunflower oil in water emulsions were produced by ultrasonic homogenizer (300 W, 5 min) with different emulsifiers (sunflower lecithin, whey protein isolate, whey protein concentrate, citrus pectin, Tween 80 (T80), and the mixture of T80 and Span 20 (S20) at two different pH (4 and 7). The particle size, zeta potential and oxidative stability of emulsions (Induction Period, IP) were measured. IP values were determined by the OXITEST® reactor which subjects the sample to an oxidative stress environment at high temperature (90°C) and high oxygen pressure (6 atm), and the higher IP value showed higher resistance of the sample to the oxidation. The smaller particle sizes (108.5 – 282.3 nm) were obtained by using small molecule surfactants. Zeta potential of lipid droplets had more negative values at pH 4. IP value was the highest at lecithin stabilized emulsions at both pH values, followed by protein stabilized emulsions at low pH. The mixture of S20 and T80 provided more oxidative stabilization compare to the using T80 alone at both pH values. Pectin stabilized emulsions were least stable to the oxidation among samples. The study showed that particle size had no apparent effect on the oxidation, whereas the type of emulsifier and pH had a significant effect on lipid oxidation.

Item Type:	Article
Subjects:	T Technology > T Technology (General)
Divisions:	Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User:	Unnamed user with email zshi@unite.edu.mk
Date Deposited:	07 Oct 2019 08:24
Last Modified:	07 Oct 2019 08:24
URI:	http://eprints.unite.edu.mk/id/eprint/376

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