Infant milk formula is a widely accepted alternative to breast milk for babies in their first year of life. Since breast milk contains all the nutrients required by young infants, formula manufacturers aim to closely match their product’s ingredients to those of breast milk.
“Functional proteins in human milk are essential for key biological functions such as immune system development,” explains Ruige Wu from the A*STAR Singapore Institute of Manufacturing Technology. “However, some of these proteins are not found, or are present at lower concentrations, in infant formula products compared to human milk.”
Recently, some manufacturers began advertising that their products contained elevated levels of functional proteins, such as á-lactalbumin and immunoglobulin G. “The ability to measure these functional proteins is very important to control and monitor the quality of infant formula products,” explains Wu. “Supplementation of formula products is expected to be regulated shortly.”
Regulation of these products requires an easy and inexpensive quantitative method to detect low levels of functional proteins in milk, which also contains abundant other proteins. However, Wu explains that existing techniques, based on high-performance liquid chromatography (HPLC), use expensive equipment and time-consuming methods, with pretreatment alone taking several hours. She and her co-workers have now developed a microchip capillary-electrophoresis (CE)-based method that is cheaper, has a shorter assay time and eliminates the need for pretreatment (1).
Wu’s team fabricated a custom-made, microfluidic-chip CE device. The device separates the functional proteins from other, more abundant proteins in the formula using isoelectric focusing. In this process, the proteins move through a gel with a pH gradient, and the point at which they stop on the gel depends on their charge. Since each protein has a slightly different charge, separation occurs. This takes just two minutes.
“The functional proteins are then transferred into the embedded capillary for further separation according to their mass-to-charge ratio,” explains Wu. This capillary zone electrophoresis separation step takes 18 minutes. The team then identified and measured the amount of protein present—while still on the CE column—using ultraviolet detection. “The concentrations of functional proteins are determined from the respective absorbance values and calibration curves,” she says.
The reliability of the device was tested with infant milk formula samples spiked with known amounts of various functional proteins. “Results close to 100 per cent recovery were obtained,” says Wu.
“Our next steps are to collaborate with industry partners in the manufacturing, or quality-control testing, of infant formula or similar protein rich products,” she says.
The A*STAR-affiliated researchers contributing to this research are from the Singapore Institute of Manufacturing Technology
Wu, R., Wang, Z., Zhao, W., Yeung, W. S.-B. & Fung, Y. S. Multi-dimension microchip-capillary electrophoresis device for determination of functional proteins in infant milk formula. Journal of Chromatography A 1304, 220–226 (2013)
Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences