Characterization of Extruded and Toasted Milk Protein Concentrates

Abstract

Important functional properties of milk protein concentrate with 80% protein (MPC80), modified with low- and high-shear extrusion, or low-temperature toasting were compared. The effect of high- and low-shear profile screws in a corotating twin-screw extruder, and 4 different ramped temperature profiles with die temperatures of 65, 75, 90, and 120 °C were compared. Extrudates were pelletized, dried, and ground to a fine powder. Toasting was done at 75 and 110 °C for 4 h for milk protein modification. Extruded and toasted MPC80 had reduced protein solubility and surface hydrophobicity. Extrusion decreased water-holding capacity (WHC). Toasted MPC80 had increased WHC when treated at 75 °C, but WHC decreased when heated at 110 °C. The treatments had no strong influence on gel strength. Reduced and nonreduced sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed peptide structural changes that occurred due to processing, especially for whey proteins. Results are discussed in terms of potential for application of extruded or toasted MPC80 in high-protein nutrition bar applications.

Extrusion modifies some physicochemical properties of milk protein concentrate for improved performance in high‐protein nutrition bars

“…not too crumbly) . Compared to the spray‐dried control, extruded MPC80 was less soluble . Despite having an opposing effect on solubility than hydrolysis, these extruded powders performed better than the control in model HPN bars .…”

“…Extrusion modified the physicochemical properties of milk protein concentrate (MPC), pea protein isolate, whey protein concentrate and soy protein isolate for improved functionality in target applications . Nutritional and other product qualities of puffed cornmeal were improved by adding extrusion‐modified whey protein isolate .…”

Effect of high-power sonication pretreatment on extraction and some physicochemical properties of proteins from chickpea, kidney bean, and soybean

“…Journal Pre-proof J o u r n a l P r e -p r o o f 92.8.1 Sodium dodecyl sulfate-polyacrylamide gel electrophoresisThe sonicated and unsonicated protein solutions were subjected to SDS-PAGE with slight modification[24]. Thirteen percent resolution gel (Acryl-Bisacrylamide) at the bottom and 4% percent stacking gel at the top were prepared.…”

Combination of treatments to improve thermal stability of egg albumen

“…About 2 mL of the sample was transferred to a 2 mL Eppendorf test tube for centrifugation at 12,000 g for 30 min. The bicinchoninic acid (BCA) protein assay was used to measure the protein content in the supernatant (Banach, Clark, & Lamsal, 2013;Smith et al, 1985). The absorbance was measured at 562 nm.…”