Alternative Development and Processing of Fermented Beverage and Tempeh Using Green Beans from Four Genotypes of Lupinus mutabilis

Abstract

In this study, the nutritional characteristics of two formulations were studied: A fermented beverage and tempeh. Green seeds from four different cultivars of tarwi (Lupinus mutabilis) were used: Andino, Guaranguito, Ecuadorian, and Peruvian. The seeds were first debittered, and then, they were fermented, using two inoculum doses and two fermentation times. For the fermented beverage, Saccaromyces cerevisae was used at doses of 1.5 and 2.5% dry weight and fermentation times of 72 and 96 h. For the tempeh, the inoculum used was the Rhizopus oligosporus strain NRRL 2710 at doses of 0.015 and 0.025% dry weight and fermentation times of 48 and 72 h. The alcoholic strength, total solid soluble, and pH in the fermented beverage were analyzed, while proximal analysis was performed for both the fermented beverage and tempeh. The results indicate that, in all cases, the Andino cultivar produced a beverage with higher alcoholic strength, regardless of the inoculum concentration and fermentation time. In both the fermented beverage and tempeh, a varietal effect was found for protein and crude fiber. The Andino cultivar had the highest protein, fat, and fiber content. The alkaloid content was similar in the beverage and tempeh, but the effect of fermentation was markedly increased with the higher inoculum dose and longer fermentation time. The alkaloid content was highest in the Peruvian cultivar, while it was similar in the remaining three cultivars. Tarwi grains have a high nutritional value, but the grain is traditionally used dry. In this study, we used green grain, which contains lower alkaloid content. Moreover, the crop cycle is shortened, and it can be used in the manufacture of fermented drinks and tempeh. In this way, we show that it is valid to use green grain instead of dried grain, constituting an improvement in the traditional use of lupine grain, and our study shows that it is possible to make both fermented drink and tempeh with green grain, showing the influence of the genotype and dosage starter.