Production and characterization of ready-to-eat chickpea flakes

Pulses are a food of global significance due to their high protein and dietary fiber content. Pulse consumption is below recommended levels in developed countries and is also declining in developing nations. Pulse flakes are currently only present in the ready-to-eat (RTE) market as niche products, but could be a means of increasing pulse consumption if the challenges of their structural weakness and long cooking times can be overcome. In this research the influence of processing conditions on the flaking behavior and physicochemical properties of Australian chickpea splits was investigated on a pilot scale flaking line. Chickpea splits were first precooked for six minutes with different steam injection times (one, three or five minutes). The precooked splits were then passed through a roller flaker with different roller gaps ranging from 0.6 - 1.9 mm and the pulse flakes were finally dried using a fluidized bed drier at either 150 or 200°C. The hard-brittle splits, through the heating and live steam injection, transitioned to a rubbery state that were flaked successfully. Moisture content and hydration properties were determined gravimetrically and differential scanning calorimetry was used to evaluate the degree of starch gelatinization and protein denaturation. Flake hardness was evaluated using a texture analyzer and flake structures investigated using scanning electron microscopy. Starch gelatinization increased with steaming time, while protein denaturation was not significantly affected. Cellular structures were conserved in the flakes produced and flake hardness was negatively correlated to steaming time. Successful production of chickpea flakes offers opportunities for the production of healthy, high-protein high-fiber RTE foods.