Bioprocessing of Lupin Cotyledons (Lupinus mutabilis) with Rhizopus oligosporus for Reduction of Quinolizidine Alkaloids

Lupin cotyledons are good source of nutrients such as proteins and lipids and around of 3.8% of toxic quinolizidine alkaloids difficult to extract. Previously It had reported by Tempeh fabrication was possible to achieve 90% of detoxification. Never before had been reported the incidence of variables of fermentation in the detoxification that could be useful for industrial scale up of process. In this investigation we studied the influence of moisture and particle size in elimination of alkaloids in a process of solid state fermentation with Rhizopus oligosporus. Wet material was fermented without forced aeration during 48 h testing two particle sizes, whole (W) and broken (B) particles. Moreover three moisture levels were evaluated at 40% (H-40), 50% (H-50) and 60% (H-60). Results showed maximum detoxification of 70.55% and 67.71% in broken cotyledons for H-60 and H-50 respectively. In whole cotyledons were achieved 64.26% and 61.08% for same moisture levels. In H-40 lower levels of degradation were showed with 47% and 52% for whole and broken particles respectively although water activity was over 0.9. Moisture over 50% did not cause a proportional increase in removal of alkaloids. Both factors, moisture and particle size influenced degradation; however less size had major incidence than moisture when water content was over 50%. Fermentation process could be useful as partial way to eliminate main toxins of Lupin. Bioprocessing of Lupin Cotyledons (Lupinus mutabilis) with Rhizopus oligosporus for Reduction of Quinolizidine Alkaloids