Research round-up: Norovirus and synthetic dye screening method

30-May-2016 - Last updated on 31-May-2016 at 08:08 GMT

Food safety research round-up - Tell us what you are working on!

Before we head to the production line we must do the background work. Here, FQN takes a look at recent examples of research relevant to food safety and quality control.

We start with work that estimated norovirus costs $64bn a year worldwide, mostly through productivity losses.

The highly contagious stomach bug sickens nearly 700 million globally every year and results in roughly $4.2bn in health care costs and $60.3bn in societal costs annually, suggested Johns Hopkins Bloomberg School of Public Health research.

Researchers suggested that much more attention and education are needed to combat a disease that also kills 219,000 a year around the world.

They said norovirus is not routinely tested for and the number of cases may be an underestimate. There is not yet a vaccine or a treatment for it.

The team developed a computer model to estimate the costs of the medical burden (such as clinic visits and hospitalizations) and the other economic costs, most notably loss of productivity.

The model estimated the cost for 233 countries, regions and territories in the world for which the United Nations has population data.

Bruce Y. Lee, the study’s senior author and associate professor in the Department of International Health at the Bloomberg School, said: “The costs associated with norovirus are high - higher than for many diseases, including rotavirus, that have gotten a lot more attention. Our study presents an economic argument for greater consideration of norovirus. It has been flying under the radar for too long.”

Onion freshness for longer

Next, advances in packaging at Michigan State University claim to help produce stay fresh longer.

Eva Almenar, with MSU's School of Packaging, focused on onions and results show that improvements can enhance safety and improve quality.

Controlling the package's atmosphere and sanitizing vegetables are not new techniques. However, finding the optimum combination of existing methods had not been tested.

The best packages helped maintain an atmosphere of elevated carbon dioxide and reduced oxygen.

When combined with a sanitizing treatment of sodium hypochlorite, a common bleaching agent, onions could endure two weeks in a package yet still satisfy a panel of trained consumers

Almenar said they found a package and sanitizer combination that led to diced onions being acceptable for purchase after two weeks of storage.

"Of all the variations that we tested, this one reduced microbial growth, respiration and discoloration, and preserved the desired aroma."

Almenar is researching gas composition packaging and containers made from renewable resources and others from egg whites and whey protein isolate, byproducts from the egg and cheese food industry.

Synthetic dye screening method

In other work, a general screening method for the detection of 19 synthetic dyes in five different food products is described. The use of most synthetic dyes in such products is forbidden in Europe.

It expands the LC-UV/Visible method developed and validated by the Government Chemist in 2006 for seven illegal dyes in one matrix, chilli powder.

Both methods apply 90:10 acetonitrile:acetone extraction at 40 degrees Celsius and reverse phase gradient elution liquid chromatography (LC) with UV/Visible detection.

No clean-up, other than filtration, and no concentration stage is required, they said.

Of the 23 dyes investigated for the new screening method in chilli powder, canned chicken in a curry sauce, fennel, palm oil, paprika and turmeric, 19 are adequately dealt with.

Researchers found poor sensitivity for Orange G, Naphthol Yellow, Congo Red and Acid Red 73.

Turmeric proved to be a very challenging matrix so the proposed general screening method in its present format is not applicable, they added.

Detecting E. coli in water

Meanwhile, researchers at York University in Canada have created a device that can detect E. coli in drinking water early.

The technology has cut down the time taken to detect E. coli from a few days to a couple of hours and is an inexpensive way to test drinking water (C$3 per test estimated).

“We have developed a hydrogel based rapid E. coli detection system that will turn red when E. coli is present,” said Professor Sushanta Mitra, Lassonde School of Engineering.

“It will detect the bacteria right at the water source before people start drinking contaminated water.”

It uses the porous hydrogel matrix, developed by Mitra’s team that cages specific enzymatic substrates that release certain enzymes in E. coli cells.

These enzymes then chemically react with the substrates to change colour. If there is no E. coli, the colour of the hydrogel won’t change, as there is no chemical reaction.

It has resulted in forming of Glacierclean Technologies, an Innovation York spinoff company, in partnership with York U.