Can turkey carcass or fish bones be used for medicine? Is milk suitable for making cheese? Protein measurements can provide answers, and Bijay Kafle measures food proteins in a new and better way.

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  Georg Mathisen (freelancer)

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He is doing his PhD at Nofima, on analyses to measure the quality of food, residual raw materials and beverages. “My focus is proteins in food. It takes a lot of time to measure fats, proteins and sugars in food with the conventional methods”, he explains.


Instead, he works with a technique called FTIR spectroscopy. It stands for “Fourier transform infrared spectroscopy”. “It’s a very fast technique. It only takes a few seconds to analyze a sample,” says Kafle.

Infrared spectroscopy means that what is to be analyzed is irradiated with infrared light. Some of the light get through, while some remain in the sample – it is absorbed.

The substances that food contains, such as proteins, fats, and carbohydrates, absorb wavelengths that are completely different from substance to substance. The wavelengths that are absorbed tell you which chemical substances are present in the sample.


“The FTIR analysis provides a chemical fingerprint of a sample. Fat has its fingerprint, sugar has its own, and so do the proteins,” he says.

The measurements say much more than how much protein, fat and sugar a sample contains. It can also provide information about the composition of the proteins and what kind of fat and what kind of sugar it is.

Getting rid of water

What Bijay Kafle has been working on are proteins that are relevant to the food and bioprocess industries. He has managed to measure them easier and faster than what is possible with other instruments. 

“My doctoral thesis is about using FTIR based on so-called dry film analysis,” he says.

This means that he makes a thin, dry film of a sample before the analysis. He places the film on a silicon plate that the infrared light can penetrate. When the protein samples dissolve in water, the water interferes with the measurements, and that is a problem. The water absorbs infrared light in the same wavelength ranges as the substances to be measured. Thus, the results are not accurate. “That’s why we want to dry the samples,” he says.

“In other FTIR analyses, we often measure the liquid and subtract the signals that come from the water. When we analyse dry films, the water is physically removed,” says Kafle. This means that the disturbances from the water are minimal and that the measurements of the proteins are more accurate.

The meter has been nicknamed “Bumble Bee” – bumblebee – and weighs seven kilograms.

Bumblebee Box

He has not only worked with theory. Together with colleagues at Sintef, he has also worked on designing and developing a portable FTIR system based on dryfilm analysis.

The result is a yellow and black box that is no bigger than it can be carried out to where it is to be used. His colleagues call it “Bumble Bee”. “Yes, there were some who thought it looked like a bumblebee. It can fly from industry to industry for sample measurements,” smiles Bijay Kafle.

He has tested “Bumble Bee” on samples from fish, chicken and turkey. We are talking about the turkey carcass and fish bones that are left after the parts that can be turned into food or feed have been utilized. “The industry uses these residual raw materials to obtain valuable substances: peptides, free amino acids and fats. They are used for animal feed and for food. We measure quality so that the quality of the products is stable and it is possible to find new markets in the future,” he says.

The measurements are better

The dry film analysis gives more reliable results than other FTIR methods, both when the samples come from poultry and salmon. For example, they show how there is more collagen – a protein that is so important for the body that it is sold as a dietary supplement – in the residual raw material from turkey than in the corresponding residue from chicken.

In milk, the measurements not only show what kind of proteins are present and what the compositions are like, but also how healthy the cow is.

“This means that dry film FTIR can be used in the dairy industry, but also on the farm, now that there is a portable instrument,” Kafle states.

Ready for the industry

The plan is to use the “Bumble Bee” in industry, for example to find out which raw materials can be turned into important dietary supplements or even pharmaceuticals. The instrument has been tested thoroughly, and it turns out that it is just as good as today’s large, laboratory-based, expensive instruments.

“This means that it is ready to be used in the industry,” says Bijay Kafle.