The study, published in the Journal of Agricultural and Food Chemistry , reports that the addition of calcium increased the thickening capacity of the protein solution, and led to increased water-holding capacity of the gel.
"The inclusion of calcium into protein solutions prepared with mWPC powders enhanced the functionality of the final whey protein dispersion, delivering superior performance characteristics when compared to other commercial whey-based ingredients on the market," wrote lead author Debra Clare from the Southeast Dairy Foods Research Center at North Carolina State University.
A recent survey by Danish 3A Business Consulting on whey and lactose ingredients, suggested that food makers are increasingly viewing whey and lactose products as an ideal means of achieving added value.
As such the global whey protein concentrates and isolates market is estimated at 395,000 MT in 2004 representing a value of just over $1bn.
Clare and co-workers developed a new process whereby they acidified the whey to pH 3.35.
This was followed by an extended heat treatment, gelation, and spray drying.
When calcium was added to a solution of the protein, the researchers observed an increase in the thickening capacity, especially under refrigeration temperatures, compared to solutions made with the modified whey protein alone.
Indeed, they state that 5.6 per cent protein was required to form the gel when 75 millimoles of supplemental calcium were used, which compared favourably to previous reports using commercial WPC powders where a minimum of six per cent protein was needed to form a gelling matrix.
A doubling of the water-holding capacity of bound or unfreezeable water of the mWPC solution was also observed.
"Ultimately, formulations can be manipulated to yield whey protein ingredients that deliver specific functional attributes under well-defined processing conditions," wrote the researchers.
"Therefore, to design products that deliver consistent characteristics for specific food applications, the details regarding the raw materials, "preprocessing" and storage conditions, and numerous experimental variables, such as ionic strength, temperature, and pH, must be identified," they concluded.
Source: Journal of Agricultural and Food Chemistry Volume 55, Issue 26, Pages 10932-10940, doi: 10.1021
/jf071613z
"Calcium Effects on the Functionality of a Modified Whey Protein Ingredient" Authors: D.A. Clare, S.J. Lillard, S.R. Ramsey, P.M. Amato, C.R. Daubert