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)
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy