Rice sorting on the Sortex S UltraVision involves identifying very subtle yellow or grey grains g

contaminated maize can’t be detected under visible light. However, the toxin does fluoresce green or yellow under UV light. LumoVision uses UV lights to illuminate maize grains flowing down a chute at 3.5m/s; cameras detect any fluorescence and air jets blow out the contaminated grains. In this way the system can process 10 to 15 tonnes of maize per hour; it can eliminate 90 per cent of contaminated maize with a yield loss of less than 5 per cent. Te challenge with fluorescence imaging,

Kelf said, is that it requires much higher power density from the lights, and all the LED profiles have to be stable and flat. Fluorescence as a biological process is only about one per cent efficient, so requires 100 times more light than imaging techniques based on reflection. ‘Food safety is one of the structural pillars of Bühler,’ said Kelf. Along with tackling aflatoxin in maize, Bühler has built its Sortex A machine that can reduce vomitoxin in wheat. Te system can remove 50 per cent or more of vomitoxin with only a 10 per cent loss of product. ‘Tis can turn a harvest from being

unfit for human consumption to one that is safe to eat,’ Kelf said. ‘Tat can have an enormous benefit, not only to the yield the customer gets because it’s gone from effectively nothing to 90 per cent of the total, but it increases the amount of food for the planet, which is good for everyone. It also makes everything we’re eating safer. Making sure the food grown is processed to a high degree in terms of food safety and food quality benefits everyone.’ Te system identifies wheat grains

contaminated with vomitoxin based on a spectral signature. It uses a number of specific wavelengths in the infrared.

Advanced sensing Bühler has also developed an online Colour and Specks Measurement Unit, which includes a digital camera with built-in optical reference tiles. It measures the colour of flour or semolina in the CIELAB colour space that corresponds to the human eye’s response to colour. A traditional approach to checking the quality of flour or semolina would be for the head miller to inspect the product in the palm of his hand.


Te camera is designed to mimic what the miller would see. Te unit gives a colour measurement in

real-time as the product flows past. Te camera can also count and classify unwanted black or brown specks – 80µm or larger – in the flour and semolina, which indicates processing deviations. Te information is then used by the miller to adjust the process to meet the required specification, Hahne explained. A quality specification may allow a maximum of 25 black specks per squared decimetre for high-quality semolina for pasta production. ‘Bühler is always looking for incremental

improvements through R&D, either reducing cost or improving quality,’ Kelf said. ‘Can you improve the image quality with a lens without adding too much to the cost, for example.’ Looking further ahead, the company is

investigating ways of using near-infrared spectroscopy to measure and sort single grains, according to properties such as protein content or moisture, but doing so at high industrial capacities. ‘Tat’s an exciting prospect for the future,’ Kelf said. O

@imveurope |


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42