A reliable, simple and cost-efficient UPLC-vwd method for simultaneously determining tocopherol and tocotrienol in peanut seeds

Abstract

Vitamin E is an essential micronutrient that is abundant in peanut seeds. However, the absence of a rapid and reliable method for determining its content has impeded advancements in peanut quality improvement. In this study, we developed an efficient ultra-performance liquid chromatography variable wavelength detector (UPLC-vwd) method for quantifying vitamin E content in peanut seeds, capable of detecting four tocopherols and four tocotrienols. Compared to traditional methods, this approach is simpler, more efficient, and highly accurate. By comparing two sample preparation techniques, it was found that slicing better reflects the true vitamin E content than grinding, as it minimizes losses caused by mechanical pressure. The method demonstrated robust stability and accuracy in both repeatability tests and spiked recovery tests, showing no significant differences compared to the national standard method. The study revealed that the cotyledons of peanuts are the primary storage site for vitamin E, being rich in γ- and α-tocopherols, which together account for over 90°% of the total vitamin E content. In contrast, the vitamin E content in the seed coat is considerably lower. Therefore, the optimized detection method minimizes seed coat interference during sample preparation, ensuring the accuracy of the results. In summary, the UPLC-vwd method developed in this study is a promising tool for determining vitamin E content and supports the improvement of peanut quality.