Synergistic Effects of Barley, Oat and Legume Material on Physicochemical and Glycemic Properties of Extruded Cereal Breakfast Products

Abstract

Cereal products are a main source of carbohydrates in the human diet. Barley and oat grains are considered as functional ingredients that can manipulate postprandial glycemic load while legume material provides high fiber and protein components to food. This research reports on hot extrusion (barrel temperature: 81.9–103.6C, die temperature: 57.3–77.3C and screw speed was around 200 rpm) to develop a barley–oat breakfast cereal which were supplemented with 10% green or yellow pea. The impact of barley–oat ratio and additional pea on physicochemical properties of extruded cereal breakfast was determined. Generally, oat positively affected the hardness of the extrudates, and the hardest extrudates were obtained when the barley–oat ratio was 50:50%. The presence of green and yellow pea increased greenness, redness, chroma and browning index of the samples. The results of in vitro starch digestion test indicated that increase of oat ratio significantly decreased rapidly digested carbohydrates and starch digestibility AUC (area under the curve) (P < 0.05). However, the presence of peas did not significantly affect the starch digestibility AUC value. Practical Applications The utilization of legume combinations with oat and barley grains can offer a unique balance of carbohydrate and protein composition of ready to eat cereal (RTE) products such as breakfast cereals. It is possible to manipulate the overall glycemic impact of RTEs through the careful utilization of cereal and protein blends. Similarly, the textural characteristics of such products could be manipulated to enhance the crispiness or crunchiness of a product.