Yarok system speeds up pathogen detection in fruit and veg industry

Yarok Technology Transfer will install its pathogen detection system at an Italian producer of fresh‐cut salads next month.

The system can identify the presence of E. coli or Listeria within 40-45 minutes, providing a “presence zero” result in six hours for E. coli or nine hours for Listeria.

Results from traditional testing systems take days and rapid tests 18-32 hours. By then, fresh food has left the production facility for supermarkets, or it's already consumed, said the firm.

Installation at the labs of Agronomia Group means the company will receive regional exclusivity for the system aimed at fresh vegetables.

Time to results versus short shelf life

Yarok said by working with fresh cut salads producers, it saw the problem of time-to-result of current testing methods versus the necessity to deliver fresh product.

“We therefore decided to find a solution, entering microbial testing: together with our CFO, Dr Glukhman, we set up a lab dedicated to development of our system.

“We focused on vegetables, but "along the road" we received a request by a major dairy in Israel for development of a module for fast identification of psychrotrophic bacteria in pasteurized milk.

“Completion of this dairy project helped us also in the development of the vegetables modules we completed now.”

Technology base

Cellular Uptake (endocytosis) is a universal mechanism existing in all active cells. Yarok discovered that the cellular uptake rate is much higher in recoverable microorganisms when recovering and uptake are activated by inducers specific for microbial type. The technology identifies the type of microbial cells by detecting a cellular uptake rate when increased by specific inducers.

Dr Vladimir Glukhman, Yarok’s CSO, on whose IP the testing system is based, said at the end of more than a year and a half of work, it completed the development stage one of the first two modules aimed at vegetables.

“We are now in the final phase before shipping the first system specifically dedicated to the fresh fruit and vegetables industry.

“After the installation of a first fast testing system in a major dairy in Israel, we focused on fresh vegetables, as this sector is particularly exposed to the risks of dangerous pathogens.

“[A] level of 1,000 CFU of E. coli − that is a very low level − can be individuated within 40-45 minutes.”

Partnership opportunities for system development

In 2014, following requests by clients for fast testing aimed at the fresh food industry, Yarok entered microbiological testing.

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A small portion of one of many images produced by the system for each sample using fluorescent microscopy. The software detects the "bacteria of interest" out of the "noise" in the images by Fluorescent Microscopy (i.e. other bacteria, relevant but dead bacteria, dirt, etc.). The end user is not presented the result as an image, but as a numeric value (the count of 'bacteria of interest"; those pathogens that can spoil the product and/or endanger human health).

The start-up is not currently marketing it as a product, instead partnering with companies for further development and improvement, as it is doing with Agronomia.

After installation of the system it will be submitted to validation (by an independent third party) about a month and a half later.

“We'll probably prefer continuing to improve the system, developing the Salmonella module before launching the system but today we are definitively open to partner and collaborate with other European producers i.e. France, UK, Germany, etc. but not Italy due to the partnership with Agronomia,” said Yarok.

Yarok said it wanted to continue improving before launching it as a commercial product. 

“We partnered with companies (i.e. Agronomia) that supported part of our development. By using our system at the present stage, those companies are interested to improve and upgrade their own internal controls and QA procedures.

“The performance (the short time-to-results) is good, therefore a company with a long term vision doesn't hesitate to invest, try it and keep the competitive advantage given by being among the first to have a pre-release of the system.”

System requirements

It requires the use of a System Kit targeted to small laboratories at production facilities or labs serving distribution centers and large retail chains.

The kit is based on Yarok’s proprietary work protocol and design sample holder for fluorescence microscopy; analytical software and supply of special growing media and reagents.

The main pieces required are a small Stomacher (or similar equipment) and a small incubator and a fluorescence microscope and can be operated by a laboratory technician used to conventional testing procedures.

Jonathan Sierra, in charge of R&D at Agronomia Group, said when it decided to upgrade internal microbiological control system, the firm looked to Israel, as it has done in the past.

“Our support for this project was predicated on our receiving regional exclusive license, and our requirement that Yarok will enable us to have testing responses within the timeframe of a production shift, before delivery of our products.

“The results have definitely exceeded our expectations; therefore we are now contracting with Yarok for development of a third testing module, for fast identification of Salmonella, together with a module for environmental swab tests for our production facilities.”

Producers and the large retail chains (those that test suppliers) will decide which techniques better fit their own specific requirements, said the firm.

“So far the feedback received by the companies and the large retail chains we have been in contact with has been extremely positive.

“We addressed so far Europe and Israel; we are nevertheless receiving expressions of interest from the US now, as the problem of product recalls due to Listeria and E. coli in vegetables has reached dramatic peaks in the US during the last 10-12 months."