Functional, textural, and rheological properties of mixed casein micelle and pea protein isolate co-dispersions.

In the midst of rising consumer health and environmental concerns, pea protein has increased in popularity as an alternative to animal-origin proteins. However, the use of pea protein in food systems is largely hindered by its poor functionality, including low solubility. The objective of this study was to measure the textural, functional, and rheological properties of a mixed plant- and animal-based protein system. Caseins, the major protein in bovine milk, are a known animal-based protein with optimal functional properties and high sensory acceptability. Through cold-temperature homogenization, insoluble pea proteins were incorporated with casein micelles in a stable, mixed, colloidal dispersion. Three blends with various casein-to-pea ratios (90:10, 80:20, 50:50) were prepared and analyzed. We hypothesized that incorporation with casein micelles would improve the poor functional properties of pea protein, and thus increase its potential uses in the food industry as a functional ingredient. The protein blend successfully underwent chymosin coagulation, a key ability of caseins, and formed protein gels with textures similar to commercial queso fresco and hard tofu. The 50% casein micelle:50% pea protein blend had better emulsification properties than pea protein alone. In contrast, this blend had the same foaming properties as pea protein alone. The mixed protein blends had similar rheological properties to skim milk, thus increasing their potential applications in the food industry. These results serve as a starting point to begin fully understanding the interactions between pea protein isolate and casein micelles combined via low-temperature homogenization and the effect on their techno-functional properties.

Use of casein micelles to improve the solubility of hydrophobic pea proteins in aqueous solutions via low-temperature homogenization.

The dairy industry struggles to maintain consumer attention in the midst of declining fluid milk sales. Current trends create an opportunity to incorporate plant-based proteins with milk to produce a high-protein, multisourced, functional food product. Plant-based proteins, such as those in peas, can be challenging to use in food systems because of their low solubility and undesirable off-flavors. Casein micelles have unique structural properties that allow for interactions with small ions and larger macromolecules that aid in their noteworthy ability as a nanovehicle for hydrophobic compounds. The objective of this study was to use the inherent structure of the casein micelle along with common dairy processing equipment to create a stable colloidal dispersion of casein micelles with pea protein to improve its solubility in aqueous solutions. We created 3 blends with varying ratios of casein-to-pea protein (90:10, 80:20, 50:50). We subjected the mixtures to 3 cycles of homogenization using a bench-top GEA 2-stage homogenizer at 27,580 kPa maintained at 4°C, followed by pasteurization at 63°C for 30 min. The resulting blends were homogeneous liquids with increased stability due to the lack of protein precipitation. Further protein analysis by HPLC and AA sequencing revealed that vicilin, an insoluble storage protein, was the main pea protein incorporated within the casein micelle structure. These results supported our hypothesis that low-temperature homogenization can successfully be used to create a colloidal dispersion with increased stability, in which insoluble plant-based proteins may be incorporated with casein micelles in an aqueous solution. Additionally, 3-dimensional microscope images of the blends indicated a noticeable difference between the surface roughness upon addition of pea protein to the casein micelle matrix. This research highlights a promising application for other plant-based proteins to be used within the dairy industry to help drive future product innovation while also meeting current processing conditions and consumer demands.

Invited review: Acid whey trends and health benefits.

In recent years, acid whey production has increased due to a growing demand for Greek yogurt and acid-coagulated cheeses. Acid whey is a dairy by-product for which the industry has long struggled to find a sustainable application. Bulk amounts of acid whey associated with the dairy industry have led to increasing research on ways to valorize it. Industry players are finding ways to use acid whey on-site with ultrafiltration techniques and biodigesters, to reduce transportation costs and provide energy for the facility. Academia has sought to further investigate practical uses and benefits of this by-product. Although modern research has shown many other possible applications for acid whey, no comprehensive review yet exists about its composition, utilization, and health benefits. In this review, the industrial trends, the applications and uses, and the potential health benefits associated with the consumption of acid whey are discussed. The proximal composition of acid whey is discussed in depth. In addition, the potential applications of acid whey, such as its use as a starting material in the production of fermented beverages, as growth medium for cultivation of lactic acid bacteria in replacement of commercial media, and as a substrate for the isolation of lactose and minerals, are reviewed. Finally, the potential health benefits of the major protein constituents of acid whey, bioactive phospholipids, and organic acids such as lactic acid are described. Acid whey has promising applications related to potential health benefits, ranging from antibacterial effects to cognitive development for babies to human gut health.