Describe their work in the Journal of Dairy Science, The method involves the use of casein micelles (CM) in cow’s milk as carriers of plant protein or other nutrients such as vitamins and minerals.
“Vegetable proteins, such as those from peas, can be difficult to use in foods due to their low solubility and unwanted bad tastes.”explains lead researcher Rafael Jiménez-Flores, professor in the Department of Food Science and Technology at Ohio State University (OSU).
“Pea protein (PP), in particular, can be a challenge to use in food systems due to its low solubility and unwanted bitterness. “
PP has become popular in sports nutrition due to its balanced amino acid composition and branched chain amino acids which aid in muscle development.
Protein is also a cost-effective, gluten-free, non-allergenic plant protein with a high percentage of hydrophobic protein (65-80%), making it a good model to represent plant protein.
With PP, soybean oil, fish oil, and rapeseed oil have been successfully encapsulated in the hydrophobic regions of CM through pH changes and ultrasonic treatments.
The team began to create three blends with varying ratios of casein to pea protein (90:10, 80:20, 50:50) by subjecting the blends to three rounds of homogenization.
The casein micelles have been essentially opened, nutrients incorporated, and the micellar structure reassembled.
The resulting mixtures were homogeneous liquids with increased stability due to the absence of protein precipitation.
Further protein analysis revealed that vicilin, an insoluble storage protein, was the major pea protein incorporated into the micellar structure of casein.
The team also notes that they were able to take advantage of the conformational changes that CMs undergo upon exposure to cold temperatures and the addition of sodium citrate to prepare a co-dispersal with the PP.
While previous research has accomplished this using ultra-high pressure and other specialized techniques, this study uses readily available dairy processing equipment that could be replicated in any dairy facility.
Stimulate product innovation
“These results supported our hypothesis that low temperature homogenization can be used successfully to create a colloidal dispersion with increased stability, in which insoluble plant proteins can be incorporated with casein micelles in aqueous solution”,the study says.
“In addition, three-dimensional microscopic images of the mixtures indicated a noticeable difference in surface roughness when adding pea protein to the micellar casein matrix.
The team recommends that future experiments focus on the amount of PP that associates within the MC, the nature of these associations, and sensory analysis.
The study also highlights the potential of other highly hydrophobic plant proteins such as soy, wheat, corn and sunflower, which could be applied in a CM encapsulation system.
“This research highlights a promising application for other plant proteins for use in the dairy industry to help drive future product innovation while meeting current processing conditions and consumer demands.”
Source: Journal of Dairy Science
Posted online: doi.org/10.3168/jds.2021-20902
“Use of casein micelles to improve the solubility of hydrophobic pea proteins in aqueous solutions via low temperature homogenization.” ”
Authors: Abigail Krentz, et al.