EFFECT OF HYDROTHERMAL, SOAKING AND GERMINATION TREATMENTS ON THE CHEMICAL COMPOSITION OF WILD Lupinus SEEDS

Abstract

Objective: To evaluate the content of nutritional compounds (NC), polyphenols (CTP), and alkaloids (TA) in seeds of Lupinus exaltatus (Le) and L. montanus (Lm) (Fabaceae), before and after application of hydrothermal, soaking and, germination treatments at different exposure times.
Design/methodology/approach: For treatment, a completely random design with factorial arrangement was applied, considering species and exposure time as factors. The NC were analyzed following AOAC methods; TA, CTP, Total Tannins (TT) and Condensed Tannins (CT) were determined by spectrometric methods. The means were compared by the Tukey test (P?0.05).
Results: The cotyledons of the seeds of both species had a higher content of protein, lipids and total alkaloids than the seed coat. Hydrothermal treatment for 6 h at 95°C increased protein and fiber and decreased TA 82 (Le) and 62.7% (Lm) relative to control. Germination increased TP (54 and 84% in both species) and decreased TA 33.5% in Le and 35.4% in Lm. NC showed no variation after application of soaking treatment, while TT decreased in Le.
Study limitations/implications: The treatments applied did not reduce the concentration of total alkaloids to levels allowed for feeding (?0.02%), so other treatments and times should be tested.
Findings/conclusions: Changes in chemical compounds in the seeds under study depend on the species and the time of exposure in each treatment evaluated. While a hydrothermal treatment increases protein and reduces ashes and AT (?60%), germination increases protein, CFT and ash, but the reduction in AT is lower (?40%).