ULTRA HIGH OLEIC SUNFLOWER OIL: PHYSICOCHEMICAL CHARACTERIZATION

DI MARCO ANDREA; PAN LUCAS; ANÓN MARÍA CRISTINA

Rosario

Congreso; World Congress on Oils & Fats and 31st ISF Lectureship Series; 2015

ASAGA - ISF

Oxidative stability of oils is mainly influenced by the degree of unsaturation. Vegetable oils rich in linolenic acid (C18:3), such as soybean and canola, are generally hydrogenated to increase their oxidative stability. As hydrogenation produces trans fatty acids, traditional breeding is used nowadays to create naturally more stable oils.Conventional sunflower oil is prone to oxidation due to its high content of linoleic acid (C18:2), around 60%. High oleic sunflower hybrids have an oxidative stability significantly better than the regular sunflower oil (Smith, 2007).In this context, a new variety of sunflower named ultra high oleic sunflower (UHO) has been developed by traditional breeding (non-GMO), that has higher levels of oleic acid (C18:1) in its oil composition.The aim of this study was to make a multi-methodological characterization of ultra high oleic sunflower crude oil (UHO SFO) by measuring different parameters (fatty acid and triglyceride profiles, refractive index, oxidative stability index and tocopherol content) and to make a comparison with high oleic sunflower crude oil (HO SFO).The fatty acids profiles determined by gas-liquid chromatography showed that UHO SFO has 92.5% and 1.1% of oleic and linoleic acid respectively, while HO SFO has 86.5% of oleic and 6.5% of linoleic acid. As a consequence of its high content of oleic acid, UHO SFO showed a predominance of OOO triglyceride, followed by StOO and POO in a lower extent.The oxidative stability index (OSI) of UHO SFO measured by Rancimat at 110 and 120 °C was around 2.5 times higher than the OSI of HO SFO. This is in accordance with the low content of linoleic acid present in UHO SFO. Tocopherol content of UHO SFO was in the range of most sunflower oils (Codex Standard, 1999).The refractive index (RI) measured at 15, 20, 25 and 30 °C showed a linear correlation with the percentage of oleic acid between 86.5% and 92.5% oleic levels. These RI curves can be used as a first quick parameter to distinguish between HO SFO and UHO SFO. As a result of this work, it was possible to achieve a general characterization of a novel sunflower oil, which has demonstrated to have an improved oxidative stability. These results are really promising for future developments in food industry.