OBJECTIVES: In order to raise awareness of the health benefits of pulses the industry needs to be able to advertise these messages to the general population. Advertising a health claim for a food item is regulated and requires approval by Health Canada based on credible evidence. The overall aim of this project is to accurately define the physiochemical and structural effects of processing of whole lentil and yellow pea varieties, and to relate these to satiety and blood glucose reduction in healthy human volunteers.
The specific objectives are:
(1) To define the chemical structure, starch and antioxidant content of whole red/green lentils and yellow pea varieties before and after cooking, and during simulated digestion;
(2) To formulate, produce, characterize and perform satiety evaluation of food items made from selected varieties of lentils and yellow pea with varying starch content;
(3) To assess the acute blood glucose response and satiety effect of whole lentil and yellow pea, and food items made from these varieties.
METHODS AND DESIGN: Standard analytical methods were utilized to obtain chemical and nutrient composition of lentil and yellow varieties, including detailed characterization of starch fractions. An in vitro digestion method was established and used to determine starch fractions and in vitro glycemic index. The effect of cooking on microstructure, starch content, in vitro glycemic index and polyphenol content was also examined. Food items made from common market class varieties of lentil and yellow pea have been formulated, produced and characterized; control foods have been developed in parallel. All foods have been analyzed for nutrient profile and will be subjected to in vitro digestibility and consumer acceptability studies. High quality human clinical trials are being used to assess the acute effect of replacing a portion of a starchy food, such as rice and potato, with boiled lentil or yellow peas, on post prandial blood glucose response (PBGR). Similar human studies are being pursued to compare the PBGR lowering effect of entrées made from equal amounts of lentils or yellow peas or a starchy ingredient such as rice, potato or wheat flour.
RESULTS: Lentils and yellow peas contain several bioactive compounds and can make significant contributions to dietary intakes of antioxidants, protein and fibre. Replacing starchy foods (potato and rice) with an equal amount of boiled whole lentil or yellow pea results in a significant (>20%) decrease in blood glucose response after consumption. Simulated digestion studies show that in vitro starch digestion and glucose release of commonly consumed pulses can differ with processing methods.
CONCLUSIONS: These data are highly relevant to inform dietary strategies for prevention and management of type 2 diabetes. The effect of processing on starch digestion can guide manufacturers in choosing optimal techniques. The high quality nature of this work qualifies it for inclusion to support health claims for pulse foods.
Project lead: Dr. Dan Ramdath (216) 217-8082 firstname.lastname@example.org