Tocopherols and tocotrienols in plants and their products: A review on methods of extraction, chromatographic separation, and detection

Vitamin E consists of four tocopherols (α-, β-, γ-, and δ-tocopherol) and four tocotrienols (α-, β-, γ-, and δ-tocotrienols), collectively referred to as tocochromanols or tocols. Tocols are well-known for potent antioxidant, anticancer, anti-inflammatory, immuno-stimulatory and nephroprotective properties. For human nutrition, diet is the major source of tocols (vitamin E) in the body. Thus, there is a need to analyze the different forms of tocols in the diet for the recommendations and to monitor the intake in the body accurately. Several methods have been developed for effective extraction, selective chromatographic separation and sensitive detection of tocols in food. Major advancements also have been made in the field of mass spectrometry for high throughput analysis of primary and secondary metabolites in fruits, vegetables, and grains. This review discusses the theoretical aspects and modern developments in methods of extraction, chromatographic separation, and detection of tocols in plants and their products. Additionally, future research challenges in this perspective are also identified.