Homogenization increases stickiness of concentrated pea protein - apple pectin mixtures

Abstract

Food binders must be sticky to glue different components together. This study evaluated the impact of homogenization of pea proteins on the stickiness of pea protein – apple pectin mixtures. A reduction in protein particle size was suggested to improve adhesion and cohesion by increasing reactive surface area, resulting in a sticky material. In addition, impact of concentrating methods, namely freeze-drying and vacuum evaporation, on concentrating the homogenized pea protein dispersions was investigated. A reduced particle size of pea proteins upon homogenization led to an increased stickiness of the biopolymer matrix when the proteins were vacuum evaporated as demonstrated by a tack test. This was attributed to a firmer and more cohesive bulk structure demonstrated by rheological, confocal laser scanning microscopy and visual observations. Vacuum evaporation prevented re-aggregation of protein particles compared to freeze-drying since less water was expelled during vacuum evaporation. These results provide new insights into tuning stickiness of biopolymer mixtures. • Homogenization of pea proteins reduced their particle size. • Vacuum evaporation maintained reduced particle size better than freeze-drying. • Pea protein-apple pectin blends with small particles were more cohesive & stickier.