The beneficial effects of consuming pulses on glycemic control are well established; however, research examining the effects of pulse fractions incorporated into extruded products is limited. The objectives of this study were to assess the effects of replacing oat flour with pea fractions in extruded cereals on post‐prandial glycaemia and insulin before and after a meal consumed at 120 min. In a randomized, repeated‐measures crossover trial, adults (n = 26) consumed cereals (35g) made with: 1) oat flour (control), 2) oat flour and pea starch (starch), 3) oat flour and pea protein (protein), 4) oat flour, pea starch and pea protein (starch+protein), 5) oat flour, pea fibre and pea protein (fibre+protein), and 6) pea fibre, pea starch and pea protein (fibre+starch+protein). Blood glucose (BG) and insulin incremental area under the curve (iAUC) was calculated pre‐meal (0– 120 min) and post‐meal (120–200 min). For pre‐meal overall mean BG, there was a time (p<0.0001), treatment (p<0.0001) and time‐by‐treatment effect (p<0.0001). During the pre‐meal period, the protein, fibre+protein and fibre+starch+protein cereals resulted in a lower (p<0.05) overall mean BG response compared to starch and control cereals. The starch+protein cereal also resulted in a lower (p<0.05) overall mean BG response compared to control. There was also a treatment effect on pre‐meal BG iAUC (p<0.0001); protein, fibre+protein and fibre+starch+protein cereals resulted in a lower (p<0.05) BG iAUC compared to control and starch cereals. Starch+protein also had a lower (p<0.05) pre‐meal BG iAUC compared to starch cereal. For post‐meal BG, there was a time (p<0.0001), treatment (p<0.05), but no time‐by‐treatment effect. There was also an effect of treatment on post‐meal iAUC (p<0.05). However, for both post‐meal BG overall mean and iAUC, posthoc testing did not identify differences between treatments. For pre‐meal overall mean insulin, there was a time (p<0.0001), treatment (p<0.0005), and time‐by‐treatment effect (p=0.001). During the pre‐meal period, fibre+protein led to a lower insulin response compared to control (p<0.05), starch+protein (p<0.05), and protein (p=0.001) cereals. Fibre+starch+protein also led to lower pre‐meal insulin compared to protein cereal (p<0.05). There was also a treatment effect on pre‐meal insulin iAUC (p<0.05); fibre+protein resulted in lower (p<0.05) insulin compared to control cereal. For post‐meal overall insulin (120–200 min), there was a time (p<0.0001), but no treatment (p=0.47) or time‐by‐treatment effect (p=0.52). There were no effects on post‐meal insulin iAUC. These findings indicate that benefits of replacing oat with pulse fractions in extruded cereals on BG and insulin are dependent on fraction type. The protein+fibre and fibre+starch+protein resulted in both decreased BG and insulin levels. Data support the use of pea fractions in extruded products designed to improve post‐prandial glycemic control.Support or Funding InformationSaskatchewan Pulse GrowersAlberta Pulse Growers

Whole pulses have been extensively studied for their favourable effects on post‐prandial glycemic control in several acute human studies. Despite the large body of evidence showing the glycemic control benefits of pulse flours and fractions, the optimal dose and combination of pulse flours and fractions that should be integrated into commercial products is unknown. Moreover, the impact of processing, such as extrusion, on glycemic response of pulse products has not been thoroughly examined. Accordingly, the current study used an in vitro model to predict the glycemic response of various pulse products, in order to identify potential formulations for human acute feeding trials. Test products comprised of pulse flours (pea, lentil, bean, chickpea) incorporated into extruded snack products at a rate of 40% (replacing corn ingredients). Pea fractions were added to extruded breakfast cereals both as individual ingredients (fibre vs. protein vs. starch) and in different combinations (e.g. fibre + protein; protein + starch; starch + fibre). Current study results showed that addition of pulse flours into extruded corn snacks led to a lower in vitro glucose release (g glucose/100g sample) over 360 min compared to an all‐corn extruded snack. While, combinations of fractions (fibre + protein and fibre + protein + starch) incorporated into extruded oat cereal had lower in vitro glucose release (g glucose/100g sample) over 360 min compared to all‐oat cereal. Analysis of raw material versus processed products showed that processing methods increased the level of starch damage and in vitro glycemic release. In summary, current study results indicate that incorporation of pulse flour or fractions into commercially processed food products will help to improve the glycemic profile of the products. This study results will aid in choosing the right pulse products for human clinical trials based on their in vitro response. Moreover, it will also provide processors with information on how processing influences the nutritional composition and the resulting glycemic response.Support or Funding InformationFunding from Alberta Pulse Growers and Saskatchewan Pulse Growers