Researchers from the Department of Food Science (FOOD) at the University of Copenhagen and the Department of Chemistry at Aarhus University have announced that they are the first in the world to analyze whole grains with long near-infrared wavelengths using the supercontinuum laser. The research may lead to better bread and beer, according to the University of Copenhagen.

Technologically, the supercontinuum laser has undergone extensive development since the turn of the century due to the development of the photonic crystal fibers on which the laser is based. The Innovation Fund Denmark project Light & Food, which aims to develop a new type of light source for near-infrared spectroscopy – the so-called supercontinuum laser – investigates, among other things, how to use this super-powerful laser to analyze food.

“The research shows a potential for commercial applications in single seed measurements,” Tine Ringsted, a postdoctoral scholar at the Department of Food Science at the University of Copenhagen, tells journalist. “It also shows that the dietary fiber beta-glucan can be measured on single barley seeds in a fast and non-destructive manner and this information can potentially be used to sort seeds according to low and high beta-glucan content.”

“The supercontinuum laser has made it possible to measure very small objects rapidly and with high energy. A supercontinuum instrument can therefore potentially be used to measure wholegrains and thus find grains with, for example, fungal or insect attacks, or to sort grains by baking, health or quality parameters,” says Ringsted.

More accurate observation
By measuring each grain, it is possible to more accurately observe the variation that naturally exists among grains from the same field and even from the same straw. The non-destructive and rapid measurement of individual grains can, therefore, be used in plant breeding to find desirable properties or in industrial grain sorting to increase quality.

“It could be very interesting to study the supercontinuum laser instrument applied to oats because they also contain beta-glucan. The instrument could also be investigated for its use of wheat, rye, corn and other seeds,” says Ringsted.

Beta-glucan in barley and especially oats has health-promoting properties such as lowering of serum cholesterol, increased satiety and stabilization of blood sugar and insulin levels after meals. Conversely, the brewing industry is not interested in high concentrations of beta-glucan, as it can clog filters and create a cloudy precipitate in the finished beer called “grandmothers cough.”

Measurements on barley flour and barley discs have previously shown some information-rich wavelengths, but it has not been possible to measure through the barley grains at these long near-infrared wavelengths due to not having enough energy from the traditional spectrometer lamp.

Laser-based sorting increases value
“A seed sorting will mean that you can obtain some grains that have health-promoting properties for use in bread, for example, and some grains that are extra good for beer. This will give both products a higher value without doing anything, but sorting the grains,” explains Ringsted, who believes that food analysis with supercontinuum lasers will become a new breakthrough in the food industry, but that it will take some years because the development is based to a high degree on interdisciplinary research, wher needs and technology have to fit together.

“It is one thing, for example, to have an instrument that can measure very rapidly and provide accurate answers, but in order for it to be practical, you must also have a sample holder that allows you to measure a large number of grains in a short time,” notes Ringsted, adding that a Swedish company (BoMill) has already developed a sample holder that can handle three tons of grains per hour, but it measures the grains at shorter and less informative wavelengths.

The technology is still new, so researchers need to find out more about the possibilities of the instrument by – for instance – measuring a larger amount of seeds, Tine Ringsted says of potential future research. She adds that studying different chemical constituents in different seeds would also be useful.

Potential for improving food
The measurement of beta-glucan in barley grains is just one example of how a supercontinuum laser can be used. In addition to single grain measurements, the Light & Food project has also examined the supercontinuum laser used in a new robust spectrometer that can potentially measure many places in a food production system. For example, this could be used in the dairy or brewing industry to follow a product from start to finish.

In addition, there is a theoretical potential for using the supercontinuum laser for the rapid measurements of gases – for example, aroma compounds or ethylene which act as a gaseous plant hormone from ripening fruits.

Overall, near-infrared spectroscopy allows for measuring more often and non-destructively compared to traditional wet chemical analyses.

“A supercontinuum laser provides, even more, options for food measurements, so it offers great potential for improving the quality of our food in the future,” finalizes Ringsted.