TEXTURE PROPERTIES OF EXTRUDATES FROM A MIXTURE OF CORNMEAL AND WHEY PROTEIN

Abstract

Texture is an important property of enriched extruded products and depends on the conditions of the extrusion process, the properties of the raw materials and the properties of the various ingredients. The main purpose of this study was the use of twin-screw extrusion to produce an extrudate based on mixtures of cornmeal and whey protein concentrate with acceptable texture properties. Three different mixtures of cornmeal and whey protein concentrate were prepared. The share of whey protein concentrate in the mixture was 7.5%, 15% and 22.5%. The mixtures were treated in a co-rotating twin-screw extruder under the following conditions: water flow rate 10.08 l / h, 12.2 l / h, 14.3 l / h; the screw speed is 300 rpm; temperature at the exit of the extruder 120 ° C; feed rate 70 kg / h. The texture properties were determined by the extruder quality indicators: the tensile strength index and the expansion coefficient. The tensile strength index was greatest for the sample with 22.5% whey protein concentrate 22.5% and water consumption 14.3 l / h. A sample with 7.5% whey protein concentrate and 10.08 l / h water had the largest expansion coefficient. The obtained results confirmed the quality of all tested samples. The results showed that enriched extrudates can be obtained with a whey protein concentrate to 22.5% to produce a product enriched with essential amino acids lacking in cornmeal.