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)
Programming cells with computer-like logic
27.07.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard
Identified the component that allows a lethal bacteria to spread resistance to antibiotics
27.07.2017 | Institute for Research in Biomedicine (IRB Barcelona)
Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.
Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
26.07.2017 | Event News
21.07.2017 | Event News
19.07.2017 | Event News
27.07.2017 | Life Sciences
27.07.2017 | Life Sciences
27.07.2017 | Health and Medicine