The effect of variety and processing on the protein quality of Canadian pulses
- Pulse Science Cluster
Dr. James House
Lead Investigator(s) Institution
University of Manitoba
To develop new amino acid scores for Canadian pulses and pulse fractions; to determine fecal and ileal protein and amino acid digestibility of Canadian pulses, pulse fractions and processed pulse commodities; to develop models for prediting in vivo ileal amino acid digestibility of pulse proteins to guide breeding programs and refine processing techniques.
This project was implemented to generate new knowledge on the effect of various processing methods (baking, boiling, generation of an extruded or puff-like snack) or genotype by environment factors (Genotype x Environment; variety x cropping location x cropping year) on measures of protein quality in a range of pulse classes (beans, peas, chickpeas and lentils). Protein quality was determined by various methods, including those required by federal regulatory agencies (Health Canada; US FDA) for substantiating protein content claims, including the Protein Digestibility-Corrected Amino Acid Score (PDCAAS), the Protein Efficiency Ratio (PER), and the proposed Digestible Indispensable Amino Acid Score (DIAAS) methods. These methods require knowledge of the amino acid (building blocks of protein) composition of the pulses, as well as knowledge of how well the proteins are digested and absorbed (digestibility). The current regulated methods require the use of a rat assay to determine digestibility, and thus their required usage creates barriers for the food industry in trying to measure the quality of new protein products. An alternative approach would include the development of a test-tube (in vitro) method of measuring protein digestibility. Over the course of this project, it was shown that different processing methods can impact the protein quality of pulses, with boiling and extrusion typically yielding the highest quality numbers. The generation of the complete protein quality data set for 10 market classes of pulses (1 chickpea, 2 peas, 2 lentils and 5 beans) provides the pulse sector and the food industry we critical information to position these important protein sources to consumers. Furthermore, it was shown that the test-tube method for measuring protein quality provides a level of accuracy and precision that should meet the standards for regulatory purposes, and these new methods are being positioned as alternatives to animal testing. In the studies examining genotype by environment differences in measures of protein quality, an extensive data set was established to highlight the factors having the greatest influence on protein quality in pulses. For example, in both red and green lentils, the measured amino acid scores were higher in 2012 vs. those observed in either 2013 or 2014, highlighting the potential for cropping year to influence protein quality. The extensive data on the impact of variety, location and cropping year on measures of protein quality will guide pulse breeders and agronomists in the development of programs designed to yield the highest quality pulse-based proteins for human consumption.
Duration/Timeline of Project (Year to Year)
2014 - 2018
Agriculture and Agri-Food Canada
Total Project Cost