Taking whey proteins down to the nano-scale may boost their stability to heat as well as help produce clear whey beverages, suggest new developments from the University of Tennessee.
Whey protein nanoparticles were produced by incorporating whey protein in microemulsions – a technique that boosted the heat stability of the whey, and produced transparent particles that could lead to innovative clear beverages, according to results published in Food Chemistry.
“The improved heat stability and reduced turbidity of whey protein nanoparticles may enable novel applications of whey proteins in beverages,” state scientists from Tennessee’s Department of Food Science and Technology.
The ‘whey’ to success
The advance taps into a growing use of whey in beverages. Whey has long been viewed as a secondary product within the dairy industry, used simply as a means of feed for animals and not as an added-value ingredient. That, however, is changing, particularly with the impact of high milk costs on the industry.
According to a 2008 report by 3A Business Consulting, the market for ingredients such as whey protein concentrate was expected to experience three to five per cent annual growth between 2007 and 2010.
Speaking to FoodNavigator earlier this year, Bruce Hein, positioning manager, marketing-EMEA for hydrocolloid supplier CP Kelco, said interest in whey-based drinks is increasing around the globe, be it in Eastern or Western Europe, or in Asia Pacific.
“Companies want to find new value added ways to use their whey, and whey beverages are an excellent way,” said Hein. “As far as finished product applications, both neutral pH and acid pH beverages are showing excellent potential for growth.”
Think big, think nano
While hydrocolloids are being explored as one way of increasing the range of whey, new research from the Tennessee-based researchers indicates that, by incorporating whey protein solutions in water/oil microemulsion, nanoscale whey particles can be formed that improve the stability of whey proteins to heat treatments (as often occurs in beverage processing).
Currently, whey proteins can clump together and form gels when heated. The whey protein nanoparticles produced in the new study were found to have significantly increased heat stability, with particles produced at pH 6.8 more stable than those produced at pH 3.5.
In addition, the whey protein nanoparticles that measured less than 100 nm were found to be transparent, which could be used in clear beverages.
“If additional heating is required, future research will be needed in order to prepare novel protein ingredients for clear beverage applications,” wrote the researchers. “Our ongoing efforts are to study how thermal pre-treatment conditions (combination of temperature and duration, whey protein isolates solution properties) can be further optimised to enhance heat stability of whey protein nanoparticles,” they added.
Source: Food Chemistry
Volume 119, Issue 4, Pages 1318-1325
“Microemulsions as nanoreactors to produce whey protein nanoparticles with enhanced heat stability by thermal pretreatment”
Weinong Zhang, Qixin Zhong