Globally, the demand for sustainable sources of dietary protein for the human population is on the rise. Canadian pulses will play an important role in meeting this demand. However, in order to achieve this potential, new data and new tools are required to better position the quality of the protein in all market classes of pulses, and how factors including processing, variety, growing location and season, affect this quality.
The research program in place will provide the industry with the needed data towards the promotion of Canadian pulses and pulse products as important sources of dietary protein. The objectives of this project are to accurately determine the quality of the protein in processed Canadian pulses (baking, boiling, generating a puff-like snack), the development of a test-tube experiment to determine how easily pulse proteins are broken down and absorbed as well as investigating the impact of growing year/location and variety on the quality of pulse proteins.
In order to determine the protein quality of processed pulses samples of lentils, beans, peas and chickpeas were either baked, boiled or a puff-like snack was generated. An animal experiment was then performed where these products were provided to rats and appropriate measurements were taken (composition of the protein, rat weight gain, amount of protein absorbed by the rat). These measurements allow for the determination of the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) and the Protein Efficiency Ratio (PER). Regulation of protein quality in the United States requires the calculation of PDCAAS, how much protein is absorbed, while Canada relies on PER, how much weight was gained.
As there is a desire to reduce animal experimentation this project has also compared the results of test-tube analysis to that of the rat experiment in an attempt to validate a method of protein quality determination that doesn’t require animals. To determine whether growing year, location or variety alters protein quality we have collected samples of three lentil varieties grown in three locations each year for three years and processed them for analysis.
Over the course of this project, we have successfully completed the processing (baking, boiling and puff-like snack) of 10 different pulse classes (1 chickpea, 2 peas, 2 lentils and 5 beans) as well as both rat and test-tube analysis of protein quality. We have determined that processing significantly alters the protein quality of pulses and the processing method for optimal protein quality differs between pulse classes. We have also evaluated the test-tube method for determining protein digestibility and have found excellent agreement between this method and that of the rat model suggesting that this method could be used as a surrogate for animal experimentation.
Moving forward, we will continue to analyze the collected pulse samples to determine what effect the growing year, location of growth and variety have on overall protein quality. Our results are providing the pulse sector with critical data to promote the protein content of pulse-based foods.
Project lead: Dr. James House (204) 474-6837 email@example.com