Thiamine (vitamin B1) and riboflavin (vitamin B2) content of field peas (Pisum sativum L.), faba beans (Vicia faba L.), and lupins (Lupinus spp. L.)

A deficient supply of B vitamins leads to health problems and decreased performance in poultry and swine. Since B vitamins are water-soluble and continually excreted by mammals, they must be provided frequently with the diet to guarantee a sufficient supply. Thiamine (vitamin B1) plays a major role in the function of the nervous system and in the energy- and amino acid metabolism. Deficiencies lead to severe health problems. Cereal-based diets are supposed to contain sufficient amounts of thiamine for poultry and swine. However, recent information on the actual content of thiamine in grain legumes is scarce. Riboflavin (vitamin B2) also takes part in the energy and amino acid metabolism. Deficiencies often lead to a loss of mobility and other health problems. Riboflavin is reported to be contained in grain legumes in large amounts. However, recent information on the riboflavin content of grain legumes is also scarce. To improve the knowledge on the thiamine and riboflavin contents of grain legumes, 87 field peas (Pisum sativum L.), 73 faba beans (Vicia faba L.), 110 blue lupins (Lupinus angustifolius L.), and 4 yellow lupins (Lupinus luteus L.), were analysed via high-performance liquid chromatography methods (HPLC) with fluorescence detection (FLD) according to EN 14122 (2014) and EN 14152 (2014). The samples were taken in the years 2011, 2012, and 2013 from organic variety field trials throughout Germany. The effects of variety and environmental conditions on the thiamine and riboflavin content of field peas, faba beans, and blue lupins were tested statistically with generalized linear models. Due to an unbalanced sample-set a data reduction was necessary. Six field pea varieties from three years and four harvest sites, six faba bean varieties from two years and three areas, as well as five blue lupin varieties from three years and three sites were tested. In total, 41 field pea samples, 57 field bean samples, and 31 blue lupin samples were used for statistical analysis. Furthermore, exemplary diets with high amounts of the three grain legume species field peas, faba beans and/or blue lupins were calculated for piglets (30%), lactating sows (35%), gestating sows (25%), pre-fattening pigs (25%), and fattening pigs (52%) as well as chicks (28%), laying hens (25%), broiler chickens (33%), geese (25%), and turkeys (40%). Those calculations were used to determine the value of these grain legumes in terms of thiamine and riboflavin supply to monogastric animals in organic farming. The thiamine contents of all grain legume species varied widely. The variation of the riboflavin content of grain legumes was less distinct. Variety affected the thiamine content of faba beans as well as the riboflavin content of field peas and faba beans. There was also an effect of harvest site or area on the thiamine and riboflavin content of all tested grain legumes. Cultivation year affected the thiamine content of field peas and faba beans as well as the riboflavin content of field peas and blue lupins. The thiamine recommendations of the GfE (Society of Nutrition Physiology, 1999, 2006) were met in all exemplary diets. Depending on their individual thiamine content and their proportion in the diet, the thiamine amount from grain legumes accounted for 32 to more than 100% of the recommended amount of thiamine. However, the riboflavin recommendations of the GfE were only met for laying hens, piglets, lactating sows, and pre-fattening pigs, because their exemplary diets contained milk powder, whey powder, green meal, and/or brewer`s yeast. The riboflavin amount from grain legumes accounted for 11 – 30% of the recommended amount. Grain legumes can contribute to the thiamine and riboflavin supply of organic diets, but wide variations of the contents must be considered.