Effect of Dairy Protein Blends on Texture of High Protein Bars

Abstract

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.

Prebiotic fibre‐incorporated whey protein crisps processed by supercritical fluid extrusion

“…Extrusion involves combined mechanical shear, pressure and thermal energy to form products with desirable texture and can be used to produce low‐moisture, shelf‐stable crisps that can be incorporated into nutrition bars or other products. However, the direct use of high amounts of whey protein in powder form in such products increases the hygroscopic properties, thus causing deterioration of the end‐product textural and shelf life qualities (McMahon et al ., ; Imtiaz et al ., ). Extrusion is an effective process to utilise whey proteins in expanded, nutrient‐enriched new products such as protein‐fortified puffed snacks, meat analogues, cheese analogues and high‐fibre products with enhanced functional and nutritional profiles (Walsh & Wood, ; Onwulata et al ., ).…”

Particle Size of Milk Protein Concentrate Powder Affects the Texture of High‐Protein Nutrition Bars During Storage

“…Formulating HPN bars with 20% to 50% protein (w/w) is a challenge as inclusion at these levels adversely affects texture and shortens sensory shelf life. High‐protein (that is, ≥ 80% protein w/w) milk protein concentrate (MPC) powders produce HPN bars that quickly harden during storage and lack cohesion (Loveday and others ; Imtiaz and others ; Banach and others ). Whey protein concentrate (WPC) or isolate (WPI), specifically their hydrolysates, produce texturally stable HPN bars (McMahon and others ).…”

Characterization of Extruded and Toasted Milk Protein Concentrates

“…Despite having positive flavor attributes and good nutritional quality, MPCs are rarely employed in high‐protein nutrition (HPN) bars containing 20% to 50% protein (Baldwin and Pearce ). Instead, whey and soy proteins including concentrates, isolates, and hydrolysates are used for better functionality (Imtiaz and others ).…”

“…HPN bars formulated with MPCs tend to have crumbly texture and lack cohesiveness (Li and others ). Another important textural parameter in HPN bars is hardness, which during storage increases to undesirable levels in HPN bars formulated with unmodified MPCs (Imtiaz and others ). The exact mechanism of instability in HPN bars formulated with unmodified MPCs is not clear, but likely due to a combination of moisture migration, limited free water availability, phase separation, and internal disulfide bond formation (Li and others ; Zhou and others ; Loveday and others ; McMahon and others ).…”