Comparison of the Composition of Tiger Nut Oil and Oils from Other Plants

Tiger nut oil (TNO), derived from the tubers of the Cyperus esculentus plant, is valued for its nutritional and health benefits. It is composed of a high amount of monounsaturated fatty acids, primarily oleic acid, which makes up approximately 60-70% of its content.

Although TNO has high nutritional values, its use in the food industry is much lower compared to other vegetable oils, such as olive or peanut oil. However, its advantages, including stability and similarity to olive oil, are becoming increasingly recognized.

This article thus focuses on comparing the composition of TNO with other vegetable oils, highlighting its exceptional properties. The overall aim is to provide an overview of the benefits it offers compared to the previously mentioned traditional variants.

TNO vs. Olive Oil

As previously mentioned, tiger nut oil is most commonly compared to olive oil.

Both oils stand out primarily in terms of their nutritional and health benefits due to their similar fatty acid compositions. Both oils are rich in monounsaturated fatty acids, particularly oleic acid, known for its positive effects on heart health.

However, a clear difference lies in their color and flavor. While olive oil has a characteristic taste and green color, tiger nut oil is neutral in flavor, with a golden-yellow hue.

There is little difference in terms of oxidative stability. This measures the induction times of the oils, which are then used to assess their durability and antioxidant activity. In both cases, the induction times are similar, with tiger nut oil having an induction time of 28 hours and olive oil 30 hours. These long time periods naturally indicate their prolonged shelf life.

Both oils have high antioxidant content, which contributes to their stability and further protection against oxidative damage.

Fatty Acids in TNO and Other Oils

The fatty acid composition of tiger nut oil (TNO) has also been compared with other vegetable oils. While the greatest similarity was found between TNO and olive oil, hazelnut, macadamia, and avocado oils also showed similar fatty acid profiles. The fatty acid profile of TNO is ideal for oils that are nutritionally beneficial and stable at high temperatures.

Unlike some other oils, it does not require hydrogenation (the addition of hydrogen), similar to high-oleic sunflower and soybean oils. This makes it suitable for various uses in the food industry, including frying and food processing.

Unsoapable Compounds in TNO and Other Oils

Unsoapable compounds in oils, including tiger nut oil, are components that do not form soap when they come into contact with alkaline substances. These compounds include various chemical compounds that do not tend to form soap. Compared to olive, soybean, cottonseed, and coconut oils, tiger nut oil has a higher content of these unsoapable compounds (2.97%) than the others (0.5-1.7%). These compounds are important for determining the origin of lipids (fats) and also serve as important markers for identifying and verifying the authenticity of the oil.

Phytosterols in TNO and Other Oils

Phytosterols are plant compounds similar to cholesterol that reduce its absorption in the intestine, potentially reducing the risk of cardiovascular diseases. Overall, tiger nut oil has a lower phytosterol content compared to olive oil but higher than coconut oil.

Tocopherols in TNO and Other Oils

Tocopherol is a type of vitamin E that helps protect cells from damage. Tiger nut oil has a tocopherol content of 120.1 mg/g, which is consistent with olive oil. Although there is only one study on tocopherols in tiger nut oil, it is verified that its lower vitamin E content compared to sunflower, peanut, and soybean oils is related to their higher content of polyunsaturated fatty acids (PUFA).

Polyphenols in TNO and Other Oils

Polyphenols are natural compounds in plants that have strong antioxidant effects and, like tocopherols, contribute to protecting cells from damage. Tiger nut oil contains up to 16 mg of polyphenols per 100 g, which is more than sunflower oil, which has only 5 mg. It is also within the range of extra virgin olive oil, which contains polyphenol levels ranging from 7.3 to 26.5 mg. Compared to other oils, TNO has higher content than soybean, sunflower, and corn oils but lower than virgin coconut oil, which contains 84 mg of polyphenols per 100 g.

Viscosity of TNO and Other Oils

The viscosity of oil indicates its resistance to flow. It shows how easily or slowly oil moves. Oils with high viscosity flow slowly, while oils with low viscosity flow quickly. This property is important in industrial processes or simply during frying, as it affects the thermal and mechanical properties of the oil during use.

In a deep-frying study, it was found that the viscosity of tiger nut oil (TNO) was lower after 30 hours than that of sunflower oil. When the proportion of TNO in a mixture with sunflower oil increased, the viscosity decreased even further. Overall, the research results suggest that TNO is the most suitable option for long-term frying compared to other vegetable oils.

Conclusion

Tiger nut oil is a valuable addition to the range of vegetable oils, mainly due to its unique fatty acid composition and high stability during frying. Studies have shown that TNO has similar properties to olive oil but can offer better stability at high temperatures. This oil also contains significant amounts of beneficial compounds, such as tocopherols and polyphenols, which contribute to its nutritional benefits. While further research is needed for a complete understanding of all its advantages, current results suggest that TNO could be a promising alternative for both consumers and the food industry.

Source: ResearchGate