Advances in extrusion for texturized whey proteins

Authors: Mukhopadhyay, Sudarsan; Onwulata, Charles

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/31/2011
Publication Date: 6/11/2011
Citation: Mukhopadhyay, S., Onwulata, C.I. 2011. Advances in extrusion for texturized whey proteins. Meeting Abstract. Session: New Processing of Dairy Ingredients. #3.

Interpretive Summary:

Technical Abstract: Dairy proteins like whey proteins play an important role in human nutrition because of their characteristic structure and associated numerous benefits such as ease of digestion, in- vivo assimilation, creating new or maintaining the muscle mass and the unique ability of boosting immune functions. Whey proteins can be can be used to boost the protein content of snack foods made from starch or corn meal; however, it requires special texturization process to achieve this new functional advantage. Non-textured whey proteins in amounts greater than 5% interferes with expansion and yield inferior crunchy snacks. To overcome these drawbacks, whey protein requires being texturized using unique extrusion processes where the protein encounters compressive and shear stresses at either hot or cold conditions. The extrusion conditions most favorable to texturing whey proteins include moisture 30 to 60%, temperature 20 to 80 deg C, and screw speed 150 to 350 rpm. The textured proteins range in viscosity from 50 to 1500 cP. Extrusion processed whey proteins are transformed into texturized whey proteins (TWP), with new molecular structures with entirely different functional properties. TWP is more digestible than spray dried whey powder. In-vivo animal model studies with TWP showed better nitrogen conversion and enhanced immune function. The advancement in the use of TWP for creating super snack foods depends on their new structural forms. Practical application: Whey proteins can be extruded along with starch to create expanded snack foods with boosted nutritional content; however, without texturization, whey proteins in amounts larger than 5% interfere with expansion, making the products less crunchy. To counter this effect, whey proteins can be texturized with starch to improve their interaction with other food components in a formulation, principally to increase extrudate expansion. Texturization enables the creation of more expanded products with boosted protein levels, which are texturally firmer and crispier product which is easier to break than the typical corn meal or corn meal without texturized WPI.