Optimization of Debittering Process of Tarwi Grain
Tarwi (Lupinus mutabilis) is an Andean legume, which played an important role in the diet of ancient cultures along with quinoa, corn, and potatoes. It is known for its high content of proteins (~45%) and lipids (~20%), adaptability to adverse climate and soil conditions, and ability to fix atmospheric nitrogen and solubilize phosphorus in the soil. Unlike the other species of the Lupinus genus, tarwi is characterized by having a high content of alkaloids (1,5-4,5%) that give the grain a bitter taste, so they must be removed to the recommended levels for human consumption (0,02%).
Traditional debittering process of tarwi grain consists of hydration (night), cooking (40 min) and washing (5-7 days) in rivers or streams that are contaminated with the removed alkaloids. The final product (“mote”) is sold in popular markets and has a short shelf life (2-3 days), if it is not refrigerated, and the process does not guarantee its safety.
Industrialization is incipient due to lack of appropriate technology. In this sense, it is proposed to optimize the debittering process that can be scaled to a semi-industrial/industrial level with respect to water consumption, wastewater generation and processing time, guaranteeing its nutritional quality and safety. For this, an automated prototype for washing will be built and the hydrodynamics in the removal of alkaloids from the tarwi grain will be evaluated. The input variables to be studied will be different geometric configurations and operating conditions of the prototype, and different tarwi grain:water ratios. And the output variables that will be determined will be the final content of protein, alkaloids, total solids in the tarwi grain, as well as the final content of alkaloids, total solids and pH in the washing water. In addition, the effect of the addition of alkali (sodium hydroxide) in cooking and temperature in hydration and washing will be evaluated.
Responsable:
Carmen Carla Quiroga Ledezma, PhD
Email: ccquiroga@upb.edu
