Determination of Fat – Soluble Vitamins and Natural Antioxidants in Seventeen Vegetable Oils

Abstract

The fat-soluble vitamins (A, D, E and K) and the most natural antioxidants (T.polyphenols, tocopherols, chlorophylls, carotenoids, δ-oryzanol, phenolic and flavonoid compounds) of seventeen vegetable oils (olive, corn crystal, corn lecuir, sunflower, palm olein, soybean, linseed, cottonseed, sesame, rice bran, peanut, blending, wheat germ, safflower, rapeseed, castor and coconut oils) were estimated. Results showed that, parameters established (acidity, peroxide value, K232 and 270nm.) to measure level of quality and fatty acid composition of olive oil were the best compared to other studied oils and also were in side the range reported by the Egyptain standareds for olive oil and International Olive Oil Cuoncel (IOOC).All vegetable oils contain a great amounts from vitamin E, especially corn lecuir, sesame, safflower, soybean and coconut oils was 36661, 30811,22540, 20334 and 16384 ppm., respectively, contrary with vitamin K recorded a lower values in all studied vegetable oil, it was ranging from 0.3 ppm in soybean oil to 6.1 ppm in rapeseed oil. On the other side safflower oil contained a higher amount from vitamin A (336.9 ppm), while linseed oil contained a considerable amount from vitamin D (46.5 ppm) followed that, rapeseed oil 23.3 ppm then corn crystal oil 22.9 ppm and wheat germ oil 21 ppm. Olive oil had a higher amount from T.polyphenols 324.91 ppm. Also results showed that, corn lecuir oil contained the highest value from T. tocopherols (212.53 ppm) compared to other vegetable oils. Carotenoids was the highest value in wheat germ oil 10.03 ppm, followed that in linseed oil 4.76 ppm , in rapeseed oil 4.5 ppm and in olive and castor oils were 2.28 and 2.05 ppm respectively. All studied vegetable oils had nearly amounts from chlorophylls, it was ranging from 0.538 ppm in corn crystal to 2.517 ppm in olive oil. δ-oryzanol contents found to be higher values in rice bran and wheat germ oils, (0.365 and 0.203 %, respectively,) but it was the lowest value in linseed oil (0.002 %) compared with other oils. This results indicated that, all vegetable oils enriched with the most identified phenolic compounds. Also it is clear from results narerigin compound was the highest value in some vegetable oils under study compared to other flavonoid compounds, whearas recorded the highest value in sesame oil (39.5 ppm.), followed by corn crystal oil (5.9 ppm.) then in corn lecuir oil (4.5 ppm.).

Castor oil (Ricinus communis): a review on the chemical composition and physicochemical properties

“…Carotenoids content found in castor oil ranged from 12.34-39.47 mg/kg β-carotene oil (Kadri et al, 2011). In another study, the carotenoids identified in castor oil was 2.05 mg/kg oil (Atta & Mohamed, 2017). Comparing with other vegetable oils, the carotenoid content of castor oil is higher than soybean with 0.37 mg/kg oil and safflower at 1.21 mg/kg oil (Atta & Mohamed, 2017).…”

“…In another study, the carotenoids identified in castor oil was 2.05 mg/kg oil (Atta & Mohamed, 2017). Comparing with other vegetable oils, the carotenoid content of castor oil is higher than soybean with 0.37 mg/kg oil and safflower at 1.21 mg/kg oil (Atta & Mohamed, 2017). Mostly, at higher temperature carotenoid content easily degrade, and this might contribute to the low carotenoid in the oils.…”

“…In addition, carotenoids have been found to correlate with oils color which is one fundamental component to access oil quality (Chew & Nyam, 2019). On determining the color of castor oil using Lovibond tintometer, it gave the red color 2.1 at 35 yellow (Atta & Mohamed, 2017). The pale yellow color of castor oil signifies the presence of the yellow pigment, carotenoids.…”

On the Tribological and Oxidation Study of Xanthophylls as Natural Additives in Castor Oil for Green Lubrication

“…Then, powders of the natural additives were incorporated into neat castor oil ( CO ) which was acquired from Abreiko, Guadalajara (Jalisco), Mexico. It was reported that castor oil contains a natural concentration of some carotenoids of about 2.05 mg/kg [ 16 ]. In this study, a molal concentration of 0.001 (approximately 568 mg/kg) of each xanthophyll was fixed, based on a previous laboratory solubility test.…”

“…Vegetable oils contain some natural antioxidants like polyphenols, tocopherols, carotenoids, chlorophyll, and δ–oryzanol [ 16 ], but the amounts thereof are not enough to allow the good oxidative capacity required for their use as industrial lubricants. Carotenoids are natural fat-soluble compounds that are made up of multiple isoprene units with a substituted and unsaturated cyclohexane ring at each termination [ 17 ].…”