Physico-Chemical Properties, Composition, and Oxidative Stability of Olive and Soybean Oils Under Different Conditions

Abstract

Commercial olive and soybean oils have been analyzed periodically in order to evaluate the influence of storage conditions on quality. The following parameters were determined every 10 days of storage: peroxide, saponification and acid values, absorption coefficients K 270 and K 232 , phenols, chlorophylls and carotenoids contents, DPPH scavenging ability, and total antioxidant activity. Edible oils were exposed to daylight and stored at room temperature in different containers with the same surface area of exposure to air either in clear glass or opaque glass bottles. Changes in oils properties were also examined after the addition of Vit-E as an antioxidant in oil samples. The results showed a gradual loss of quality during storage, especially in clear glass bottles. The addition of the antioxidant, however, significantly reduced the deterioration and oxidation rate in the oil. The best containers for commercial packing of oil were opaque glass bottles containing antioxidant products.

Effect of Sunlight on Fatty Acid Composition of Tomato Seed Oil Stored in Different Colored Bottles

“…In terms of color, opaque glass bottle seems to provide the best protection. The findings of Makni et al (2015) are in agreement with the best preservation of vegetable oil colors by means of opaque bottles. Lycopene from carotenoids, which are thought to give tomato seed oil its redness, becomes isomerized and thus loses overall color intensity when exposed to light (Shi et al, 2008;Shao et al, 2013;Shao et al, 2015).…”

“…Preservation of edible oils in coloured bottles affects oxidation reactions significantly. Amber colored glass provides better protection from light than transparent glass and photoxidation takes place more easily in the transparent case (Wang et al, 2014;Makni et al, 2015). The purpose of this study was to determine the change in the fatty acid composition by the exposure of the tomato seed oil to the sunlight and the extent to which this change was affected by the transparent, amber and opaque glass bottles.…”

Determination of the triacylglycerol content for the identification and assessment of purity of shea butter fat, peanut oil, and palm kernel oil using maldi-tof/tof mass spectroscopic technique

“…From this study (Figure 1b) shea butter gave TAG peaks C 54:1 (at m/z 911.7), C 54:2 (at m/z 909.6) and can be attributed to the susceptibility to attack on unsaturated fatty acids such as linoleic acid and oleic acid by activated oxygen [21,22]. In the presence of activated oxygen, the unsaturated fatty acids, due to the presence of the high electron density at the point of unsaturation tends to have a high affinity for the oxygen, which leads to their oxidation [28,29]. The activated oxygen is likely to be produced through thermal processes during the production and refining of the oils.…”

Efeito da condimentação permanente com alho desidratado e in natura nas características físico-químicas, atividade antioxidante e estabilidade térmica do azeite de oliva

“…O azeite de oliva representa a principal fonte de lipídios da dieta de países mediterrâneos com impacto na saúde e no bem-estar (Perestrelo et al, 2017). Os benefícios nutricionais devidos ao consumo do azeite de oliva estão relacionados principalmente à sua composição de ácidos graxos, ao alto teor de ácido oleico e à razão equilibrada de ácidos graxos saturados e poli-insaturados (Makni et al, 2015). Os benefícios do azeite na saúde humana são atribuídos principalmente aos compostos fenólicos e a capacidade antioxidante, importantes na prevenção de muitas doenças, como câncer, distúrbios inflamatórios, degeneração neurológica, doenças coronárias e diabetes mellitus tipo 2 (Foscolou, Critselis & Panagiotakos, 2018;Perestelo et al, 2017;Sacchi et al, 2017).…”