The effects of extrusion on nutrient content of Canadian pulses with a focus on protein and amino acids

Abstract

Alternative sources of protein will be required in both human and animal nutrition to support ingredient sustainability and nutrient demands of a growing world population. Extrusion is one technique utilized to process pulses and is reported to increase starch and protein digestibility but also has the potential to transform nutrients into non-nutritious compounds. This study sought to compare the effects of extrusion on nutrient composition in Amarillo peas, Dun peas, lentils, chickpeas, and faba beans, with soybean meal (control). Each pulse was extruded at 18% or 22% moisture and 110, 130, or 150 °C. Compared to whole samples, extrusion increased crude protein content of Amarillo and Dun peas, and lentils, and it decreased in soybean meal ( P < 0.05). Compared with whole samples, extrusion increased methionine content in chickpeas and lentils ( P < 0.05), with no effect in Amarillo or Dun peas, faba beans, and soybean meal. Cysteine content increased in extruded Amarillo peas compared with whole pulses, and decreased in soybean meal ( P < 0.05). Results suggest that extrusion can positively affect protein and amino acid content of pulses, however, specific changes differ by pulse/legume type.