Ensuring yogurt quality

29 November 2021

X-ray inspection technology has enabled a Greek dairy processor to maximise product safety and brand protection for its range of yogurts.

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X-ray technology works on the principle of producing X-ray wavelengths from a generator tube which traverse through a product to be inspected onto a line sensor. The line sensor system converts the incident X-rays into a greyscale image that is further processed and ultimately displayed on the screen. The darker the area of the image, the higher the density and in this way foreign bodies which are denser than the product can be detected.

As part of a range of enhanced quality control procedures Tyras S.A - Hellenic Dairies has installed three Ishida IX-GA-4075 X-ray inspection systems to check individual pots of yogurts.

While the automated filling lines operate to the highest hygiene standards, it is vital that the company remains vigilant against the ingress of any foreign bodies such as metal, glass or other unwanted items that could contaminate the yogurt during production.

“The introduction of X-ray inspection technology has given us that extra degree of reassurance that product quality has not been compromised in any way,” said Ioannis Balodimos, plant manager at Tyras.

The sensitivity of Ishida X-ray machines means it is able to detect impurities down to 0.3mm in size, while the place of contamination can also be accurately pinpointed. In particular, the machine’s self-learning Genetic Algorithm (GA) technology delivers maximum detection sensitivity and reliability. The technology focuses the machine to identify difficult to detect contaminants with a high degree of accuracy, even at high throughput rates, using image data analysis over a number of trial runs.

Because it is common in food production for similar contamination problems to recur, data logging can help build up a more precise calibration protocol with each trial. This enables permanent or recurring defects to be easily identified during the inspection process.

The Ishida IX-GA models were supplied by Ishida’s Greek agent, Europack. “We have a close working relationship with Europack and so we trusted their recommendation of the Ishida X-ray as being one of the best in the market,” continued Balodimos “We were very pleased with the first unit we installed, and this led to the order of two more machines.”

Tyras is using the X-ray systems to check individual yoghurt pots that are running through the inspection chambers in a twin lane configuration at around 300 packs per minute.

At present, one Ishida X-ray machine is in operation 16-hours each day while the other two are working 10-hours daily.

Set up and product changeovers can be carried out quickly thanks to a simple to use touch screen on the equipment. Features such as the sensitivity of the inspection process can be adjusted at the touch of a button while up to 100 product settings allows for fast changeovers. The stainless-steel design means the machines are easily cleaned, and the belt conveyors can be removed without the need for any tools.

“The Ishida X-rays are very straightforward to operate and maintain,” confirmed Balodimos “We received training from Europack to help ensure we maximise all the benefits of the machines. Above all, the IX-GAs are reliable; and it is for this reason in particular that we will continue to invest in Ishida for our X-ray inspection requirements, as we have done at our Larissa plant with a new Ishida X-ray for inspecting packs of butter.”