Value-added processing of pulse starches from seeds to industrial products through multi-disciplinary approaches

In Year 1 (August 2021 – August 2022) of the Strategic Research Initiative (SRI) Program, the nine research programs at the University of Saskatchewan and University of Manitoba have worked collectively to make good progress in all the five pillars outlined in the original proposal. Eight commercial pulse starch/flour samples have been collected, characterized, and distributed to the collaborators working on the different research themes. In Pillar 1, we have clearly demonstrated that tempering, infrared heating, and germination can be utilized to enhance the dehulling efficiency and improve the protein extraction rate during dry fractionation of round pea, faba bean, and wrinkled pea. We will continue to determine how these “clean-label” treatments will influence the functional properties and nutritional quality of the derived fine (protein-rich) and coarse (starch-rich) fractions from the different pulses. We have also simplified the wet-milling method to separate starch (up to 95.0% purity) and protein (up to 88.7% purity) in starch-rich pulse flours from commercial sources. In Year 2, we will continue to employ different wet-extraction conditions varying in pH and temperature and then utilize a “surface plot approach” to determine the optimal conditions that can be used to efficiently extract starch and protein of high purity.

In Pillar 2, two M.Sc. students have joined the team to investigate physiological benefits of resistant starch from pea in a pig model and to develop pyrodextrin (a highly soluble dietary fiber) from pea starch. In Pillar 3, we have shown that fermentation of starch-rich flours of yellow pea, lentil, and faba bean by A. oryzae under the optimal conditions increases their crude protein contents from 7.8% to 33.2%, from 16.5% to 51.1%, and from 14.5% to 40.9%, respectively. With the addition of ammonium salts only (ammonium sulphate, ammonium phosphate, or a combination of ammonium sulphate and phosphate at a 1:1 ratio), we are able to markedly increase the crude protein contents of the starch rich flours up to 51.1%.

The researchers have shared the novel findings with the industry partners and potential end users during the reporting period. We have presented and discussed the new results collected from Year 1 at our annual on-campus workshop at University of Saskatchewan on September 28th, 2022. With highly-qualified personnel (HQP) in place in the different research groups and the required resources, expertise, and research capacity being readily available, the research team will continue to achieve progress in the current SRI Program in Year 2.