Pea protein microparticulation using extrusion cooking: Influence of extrusion parameters and drying on microparticle characteristics and sensory by application in a model milk dessert

Microparticulated proteins are potential fat replacers to reduce the caloric value of foods. In contrast to whey protein, knowledge on the formation of microparticles based on pea protein using extrusion cooking is limited. This research aimed at evaluating the impact of extrusion parameters and subsequent effects of spray- and freeze-drying on the physico-chemical and sensorical characteristics of the resulting `functionalized´ pea protein microparticles. A method for pea protein microparticulation is presented. Extrusion parameters could be varied such that particles suitable for fat replacement in terms of size range were formed. Particle size was mainly dependent on extrusion temperature and residence time. The screw speed was of negligible influence. Post-extrusion spray- or freeze-drying did not affect the particle size. To assess the aggregation mechanism of particulation, the stabilizing forces were investigated by applying a protein interaction assay. It was found that pea protein microparticles were mainly stabilized by hydrophobic interactions. The ability of functionalized pea proteins to replace fat while maintaining authentic dairy flavour was tested sensorically in a model milk dessert. The incorporation of microparticles in a fat-reduced milk dessert resulted in almost the same creamy perception compared to the full-fat milk dessert as control. An important finding was that drying of the microparticles lowered undesired grassy/beany off-flavours, which are currently typical disadvantages of pea protein usage within food.