Effect of Dairy Protein Blends on Texture of High Protein Bars

A number of studies have focused on bar hardening of protein bars. The instrumental texture analyzer measurement of peak force is known to measure bar hardness or firmness. However, to understand overall bar texture, another important texture dimension, crumbliness/cohesiveness, needs to be considered. This study was based on three functionally modified dairy proteins, including one whey protein concentrate and two milk protein concentrates. A mixture design was used to study the synergistic effects of these three proteins on bar texture. Instrumental texture parameters that correlated with sensory texture were developed. Peak force (Force 1) was correlated with firmness (being opposite of softness) dimension, and maximum negative force (Force 2) was correlated with cohesiveness (being opposite of crumbliness). Mathematical models with R2 > 90% were developed to optimize the texture over a 12‐month storage period, with storage at 20C, for bars using one or more of the three proteins. PRACTICAL APPLICATIONS Protein bar manufacturers will be able to select the type of dairy protein and the level of the proteins in a blend required to achieve desired texture in bars based on the findings of this study. The whey protein concentrate, used in this study, proved to be important to minimize firmness over time. The milk protein concentrates in this study performed differently from each other in bars due to the different modifications made during the manufacture of these ingredients. This study has also shown the importance of the crumbliness/cohesiveness texture dimension and investigated a method to quantify this using instrumental texture analysis. The mixture design approach used in this study could be applied to a bar manufacturer's specific formulation to develop a predictive model that will help them adjust key ingredient levels to manipulate the texture in bars.