Blue lupine seeds protein content and amino acids composition

Abstract

Lupine seeds are promising soy replacement in food products and feeds. Eighteen cultivars of blue lupine seeds were examined to indicate the one most favourable in protein content and quality. Two parameters were studied, i.e. total protein content (with the Kjeldahl method) and amino acids composition (with the ultra performance liquid chromatography technique). Both parameters studied were variable and depended both on the cultivar and on the place of cultivation. Protein content was in the range of 28–41% and the worst cultivar, regardless of cultivation place, was cv. Kalif (average total protein content 29.37 ± 1.14%), while the best cultivar was Boruta (average total protein content 37.43 ± 0.98%). The blue lupine seeds were rich especially in leucine (5.3 ± 0.5–9.7 ± 0.5 g/16 g N), threonine (2.4 ± 0.7–4.9 ± 0.1 g/16 g N) and lysine (2.7 ± 0.4–5.6 ± 0.1 g/16 g N). The richest among all amino acids studied were the cv. Bojar seeds from Wiatrowo and cv. Oskar from Przebędowo. It was not possible to choose one cultivar preferable from the nutritional point of view, because a strong influence of cultivation place on protein content and quality was observed, especially as to the precipitation sum.