the richest source of vitamin E (Table 2.2). Sunflower has a high content of α‐tocopherol. Groundnut and cottonseed present balanced levels of α‐ and γ‐tocopherol. Olive oil presents a similar tocochromanol profile to sunflower, however its α‐tocopherol content is lower (Velasco and Ruiz‐Méndez 2015). The content of tocopherol in soybean at pH 6.8 is β‐, γ‐tocopherol 0.27 ± 0.02, δ‐tocopherol 0.47 ± 0.00 and α‐tocopherol 0.02 ± 0.00 mg/g neutral lipid of oil bodies (Chen et al. 2014).
Some phytosterols are important components, they are part of the steroids group, and participate in the chemical defense of the plants, as for example, triterpenoids or campesterol which is one of the most important phytosterols and has a similar structure to cholesterol. Because of this, dietary phytosterols reduce intestinal absorption of cholesterol and reduce its levels (Plat and Mensink 2005). Technologically, phytosterols increase thermal stability of oils with high levels of polyunsaturated fatty acids (Winkler and Warner 2008).
These compounds can be present in the oil in free form or esterified with glucosides, ferulic acid, or fatty acids. Ferulic acid‐esterified sterol is known as oryzanol and has been reported to have diverse health benefits, including hypolipidemic and antioxidant effects or stimulation of growth and hypothalamus activity (Dunford 2004). β‐sitosterol is the phytosterol predominant in the profile of vegetable oils. Brassinosteroids, which are plant hormones essential for normal growth and development (Bishop and Yokota 2001) are present in high concentration in rapeseed oil. Soybean decreases its content of β‐sitosterol with pH changes, at pH 6.8 0.82 ± 0.10 mg/g neutral lipid of oil bodies, at pH 9.5 with 0.73 ± 0.05 mg/g, and at pH 11.0 with 0.62 ± 0.04 mg/g (Chen et al. 2014).
Table 2.2 Composition table from Food Data Central form USDA (values per 100 g of oil).
| OILS | Energy (kcal) | Total lipid (g) | FA total saturated (g) | FA total MU a (g) | FA total PU b (g) | Vitamin E c (mg) | Vitamin K d (μg) |
|---|---|---|---|---|---|---|---|
| Sunflower oil | 884 | 100 | 10.3 | 19.5 | 65.7 | 41.1 | 5.4 |
| Canola Oil | 884 | 100 | 7.4 | 63.3 | 28.1 | 17.5 | 71.3 |
| Soybean oil | 857 | 100 | 15.7 | 22.7 | 57.7 | 8.2 | 183.9 |
| Groundnut oil | 884 | 100 | 16.9 | 46.2 | 32 | 15.69 | 0.7 |
| Cottonseed oil | 884 | 100 | 25.9 | 17.8 | 51.5 | 35.3 | 24.7 |
| Flaxseed oil | 884 | 100 | 9 | 18.4 | 67.8 | 0.47 | 9.3 |
| Poppyseed oil | 884 | 100 | 13.5 | 19.7 | 62.4 | 11.4 | ‐‐‐ |
| Sesame oil | 884 | 100 | 14.2 | 39.7 | 41.7 | 1.4 | 13.6 |
| Safflower oil | 884 | 100 | 7.5 | 74.8 | 12.2 | 34.1 | 7.1 |
| Olive oil | 884 | 100 | 13.8 | 72.9 | 10.5 | 14.35 | 60.2 |
| Coconut oil | 892 | 99.1 | 82.5 | 6.3 | 1.7 | 0.1 | 0.6 |
a monounsaturated
b polyunsaturated
c α‐tocopherol
d phylloquinone.
Table 2.3 Composition of main fatty acids from oilseed oils.
| Oilseed oil | Main Fatty Acids | Quantity (%) | References |
|---|---|---|---|
| Soybean oil | Palmitic acid C16:0 | 10.42 ± 0.07 | Zhong et al. (2015) |
| Oleic acid C18:1 | 22.85 ± 0.04 | ||
| Linoleic acid C18:2 | 53.62 ± 0.05 | ||
| α‐linolenic acid C18:3 (n‐3) | 7.33 ± 0.07 | ||
| Sunflower oil | Palmitic acid C16:0 |