The tocopherol content of different legume crops

The Tocopherol Content of Different Legume Crops Giovanna Boschin1*, Donatella Resta2, Anna Arnoldi1 1Department of Endocrinology, Pathophysiology and Applied Biology, University of Milan, Via Balzaretti 9, I-20133 Milan, Italy; *Corresponding author: giovanna.boschin@unimi.it 2HPF-Nutraceutics, Via Balzaretti 9, 20133 Milan Italy. The health promoting properties of vegetables are strongly related to the presence of bioactive phytochemicals such as tocopherols (T). They act as antioxidants by trapping radical intermediates, reducing the risk of chronic diseases, such as cardiovascular diseases. They can exist in four regioisomers (alfa, beta, gamma, delta) which differ for the methylation pattern of the phenolic ring and have different biological activities. In this work, seeds from the main legume crops, i.e. soybean, lupin, chickpea, lentil, bean, pea, and broad bean, were analysed in order to evaluate the contribution of legumes in the total intake of tocopherols. The seeds were dehulled, ground, the oil was extracted with Soxhlet with hexane, then analysed by a HPLC equipped with a fluorimetric detector, using a Lichrosorb Si60 column and n-hexane:isopropanol (98:2, v/v) as eluent. Gamma-T is the most abundant isomer in all samples, whereas beta-T is never detected. Alfa-T and delta-T are very sensitive to each specific sample, for example alfa-T is absent in common beans, whereas delta-T is absent in narrow-leaf lupin. In soybeans, the total T content is about 14 mg/100 g, in Albanian peas it falls in the range between 10 and 14 mg/100 g, in Italian peas and broad beans is about 6 mg/100 g, in Italian common beans is about 3 mg/100 g, and in chickpeas is about 11 mg/100 g. The contents of the three lupin species are the following (average values): pearl-lupin 10.2 mg/100 g, white lupin 9.7 mg/100 g, and narrow-leaf lupin 8.6 mg/100 g, respectively.