A new way to measure the ability of pulse flours and protein concentrates to absorb oil

Researchers from the Canadian Grain Commission’s Pulse Research program, the University of Saskatchewan, and Agriculture and Agri-Food Canada have developed a new, more accurate method for measuring the oil absorption capacity (OAC) of pulse flours, protein concentrates, isolates, starch and fiber. The amount of oil in a food ingredient affects the way a finished product looks, tastes and feels and too much or too little oil will make a food unappetizing. Food manufacturers will be able to use this new OAC method to identify pulse ingredients that can be used successfully in recipes. The development of this method comes at an opportune time since foods made with pulses are becoming increasingly popular.

OAC is measured by mixing a sample of pulse ingredient with excess oil, allowing it to be absorbed by the sample, and spinning the sample at low speed in a centrifuge to separate unabsorbed oil from the solids. The unabsorbed oil is removed, and the amount of oil absorbed by the sample calculated. Dr. Ning Wang and his colleagues observed that the conventional way of measuring OAC led to inaccurate results because some of the less dense ingredients also drained off as the unabsorbed oil was being removed and some ingredients reabsorbed the oil remaining in the sample tubes after centrifugation.

The research team’s new method to measure OAC uses a device that holds filter paper in place while centrifuging samples upside down. This allows the unabsorbed oil to pass through the filter paper and all the sample material to remain in the test tube. This new procedure has proven to be a more accurate, efficient and reliable method for measuring OAC and can be applied to a variety of pulse and soybean ingredients.