Evaluation of technological and functional properties of breakfast cereal based on flax meal and rice flour

Abstract

In order to change eating habits, the consumption of breakfast cereal products has been increased due to its ease of consumption, cost-effectiveness and high nutritional value. These products must have a compact and dense structure with low porosity to maintain the texture and crispness of the product during immersion in milk due to the slow absorption of water. Due to obtain the desired texture and decrease in decomposition of starch, using grain with high amount of fiber and apply extrusion process would be crucial. Although the integration of fiber in products poses technological challenges, the desired characteristics can be achieved by using rice grains and maltovextrin as important sources of starch. In this study, with the aim of achieving breakfast cereal product with desirable physicochemical, functional and sensory properties, the effect of extrusion process variables including humidity (12, 15 and 18%), screw speed (140, 170 and 200 rpm) and Flaxseed oil cake (10, 20 and 30%) was evaluated on the characteristics of the products using a response surface methodology. The results showed that the increase in humidity led to an increase in dry hardness, bowl₋life hardness, water absorption index and a decrease in water solubility, lightness, redness and yellowness index of the product. Increasing the screw speed increased the water solubility, redness, yellowness and decreased expansion ratio, bowl₋life hardness, water absorption and brightness. Increasing the level of flaxseed oil cake increased bowl₋life hardness, redness index and decreased expansion ratio, brightness index, yellowness, water absorption, water solubility first decreased and then increased. The results of this study show that the use of flaxseed oil cake up to 17% as a rich source of dietary fiber in extruded breakfast cereal products can lead to the fabrication of products with desirable technological and sensory characteristics