Probing changes to infant milk formulations

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

Journal information

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)

Media Contact

A*STAR Research Research asia research news

All latest news from the category: Life Sciences and Chemistry

Articles and reports from the Life Sciences and chemistry area deal with applied and basic research into modern biology, chemistry and human medicine.

Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors