Testing
Speedy advice in the hunt for potential pathogens
SGS NZ has been searching for technologies to help food industry manufacturers, especially those in the FMCG markets, to release products earlier with confidence – while keeping costs minimal.
After rigorous validations and evaluations, SGS NZ says it now has the confidence to introduce to the New Zealand food market the highly specific and sensitive VIDAS® technology.
VIDAS uses the enzyme-linked fluorescent assay technology which the company says has been tried and tested worldwide as a leading automated pathogens testing platform.
Over the past year SGS has evaluated this procedure for a wide range of foods and plant hygiene monitoring surfaces for salmonella and listeria monocytogenes/species and had it accredited by IANZ.
The recent US cantaloupe related listeria outbreak, which resulted in 29 deaths and a further 139 cases of infection across 28 American states, and the Spanish-egg related salmonellosis in the UK which affected 262 people, to the need for intensive testing of product for these pathogens before release to the market, SGS says.
Manufacturers however, are under constant pressure to get their finished products to the market quickly, while keeping inventory levels lean.
There is a huge cost to storing the finished product in the warehouse or cold store until clear laboratory results for these pathogens are received.
Due to the high mortality rates associated with listeriosis and salmonellosis, food safety regulations in New Zealand mandate that all ready-to-eat products should be free of salmonella and listeria monocytogenes.
Traditional laboratory culture methods may require between six to 10 days to deliver results and manufacturers may resort to the “ship and pray” approach, which could result in expensive recalls or shortened available shelf life.
Both pathogens are routinely implicated in food poisoning cases from meat, poultry, seafood, processed dairy (including infant formula), delicatessen
products, bread and pastry mixes, fruits and vegetables, animal feeds, herbs and spices and are also commonly detected on manufacturing surfaces.
The new VIDAS technology, exclusive to SGS NZ, offers a significant advantage over traditional culture-based microbiological testing, SGA says.
VIDAS technology for salmonella shows the absence of salmonella within 24 hours and listeria LDUO will provide results for listeria monocytogenes/species within 48 hours.
“MAF Food Safety Authority has a zero tolerance to presence of listeria monocytogenes and salmonella in ready-to-eat foods,” says SGS technical and quality manager Dr Guru Parkar.
“The VIDAS technology was carefully selected, verified and accredited at the SGS NZ lab in response to the constant demand from compliance and quality managers of the food Industry for a rapid yet reliable method that satisfied MAF compliance criteria,’’ he says.
Mr Parkar says that cost was a major consideration as they searched for technologies that would help customers release products to market sooner.
“We didn’t want to be burdening these businesses with a substantial increase in testing costs. VIDAS technology is in keeping with the NZFSA listeria monocytogenes risk management strategy to focus on controls that are practical, feasible and cost effective,” he says.
“Food manufacturers can be confident of results generated by the rapid VIDAS technology both for salmonella and listeria monocytogenes/species while releasing their products to the markets earlier than ever before,” says Mr Parkar.
“During these difficult economic times food manufacturers can take solace in the fact that this advanced technology can vastly reduce storage costs and increase available shelf life for the product.
“In short, food manufacturers can optimise their production and hygiene monitoring, accelerate corrective actions and avoid the risk of costly product recalls,” he says.
Innovative detection system for dangerous foodborne pathogens
3M says its new molecular detection system is a fast, accurate and easy-touse method of detecting dangerous pathogens like Salmonella, E. coli O157 and Listeria, that can shut down businesses and threaten public health.
The 3M molecular detection system is based on a combination of single technologies involving isothermal DNA amplification and bioluminescence
detection. The system was designed with customer testing needs in mind and has resulted in a compact, simple, robust system that offers easy implementation and low maintenance without compromising accuracy and reliability, the company says.
“Leveraging 3M’s record of innovation, including close collaboration with our customers, we believe we’ve found a transformational solution that makes for a faster and simpler way of accurately detecting pathogens,” says vice president and general manager of 3M Food Safety Francine Savage.
“Just as 3M petrifilm plates succeeded by melding sophistication with simplicity, the 3M molecular detection system optimises technicians’ time and productivity, improving bottom lines, protecting brands and ensuring public health.”
Sensitive, uncompromised results in a compact unit
The new system delivers highly sensitive results by targeting and amplifying nucleic acid in enriched samples. The automated technology has been evaluated with a variety of food types including produce, meats, processed foods, pet food and food-processing related environmental samples. The instrument is sleek and compact – taking up less counter space than a laptop computer, making it portable and adaptable to various lab environments.
“Pathogen testing has now been made simple and affordable”, says Food Safety global marketing development manager Niki Montgomery.
“Food processors will benefit greatly from the system’s affordable accuracy and fast time to results, minimising downtime in the lab. Numerous organisms can be tested in a single run and it was designed to help our customers perform fewer repeat tests and make critical decisions faster.”
Three assays available, validation efforts underway
The molecular detection system uses simplified handling steps and reduces the time to result. Each type of assay uses the same software interface and same DNA extraction protocol for testing between one and 96 samples per run. Assays for Salmonella, E. coli O157 (including H7) and Listeria are available immediately, while a test for Listeria monocytogenes is expected early this year. 3M is continuing to develop a full portfolio of pathogen
testing solutions.
Independent laboratory studies with the 3M Molecular Detection System are currently underway to pursue global method recognitions.
“In our evaluation of the Listeria species assay, we liked the small footprint of the system as well as the quick delivery of results after sample enrichment,” says Dr Martin Wiedmann, a professor in Cornell University’s Department of Food Science who studied the system’s analyses of samples taken from meat-packing, seafood processing and retail locations.
“This system definitely illustrates the potential of isothermal methods for rapid detection of foodborne pathogens.”
For more information:
Tel: 0800 808 182
Visit: www.3m.co.nz/foodsafety
Fruitful study into health benefits of golden kiwifruit
Carbohydrate chemists from crown research institute Industrial Research Ltd (IRL) have uncovered the secrets behind the cell wall of Zespri’s patented variety of gold kiwifruit, opening the door to new understandings about the fruit’s digestive benefits.
Kiwifruit marketer Zespri, which owns the plant variety rights for ZESPRI®GOLD Kiwifruit (Actinidia chinensis var.Hort16A), commissioned the research to find out more about its potential health benefits.
IRL chemist Dr Simon Hinkley says a number of studies have shown kiwifruit to be beneficial for the digestive system because they are high in fibre and contain bioactive agents that promote the growth of beneficial intestinal bacteria. Among these agents are the polysaccharides or complex carbohydrates.
But, says Dr Hinkley, most research published to date has focused on the original, green variety with a gap in knowledge about the newer gold kiwifruit.
The IRL team found little difference between the types and total levels of complex carbohydrates in the two varieties although ZESPRI®GOLD Kiwifruit has higher amounts of a compound known to break down more easily in the stomach.
Zespri health science manager Lynley Drummond says the research has provided the tools needed to study whether there are different health benefits from eating a gold or a green kiwifruit.
“Now we know the structure of the components in each variety, we can follow them through the digestive process.”
She says that research is being carried out through a collaborative project involving IRL, Plant and Food Research, AgResearch and the Riddet Institute.
“We’ve been able to track the fate of fibre from both green and gold kiwifruit as it passes through the digestive system, helping us understand how
and why kiwifruit are good for people.
“It’s no longer good enough to say a product must be good for you - consumers are rightly demanding robust science that proves the efficacy of foods that make claims about their health benefits.”
The original, analytical work by IRL’s carbohydrate chemistry team has been published in Carbohydrate Polymers, a peer-reviewed journal focusing on carbohydrate polymers with industrial uses.
Lynley Drummond says findings from the very successful collaborative, followup research, will be published in the near future.
Choice of probiotic feed supplements for livestock
By Grant Bennett, Janette Busch and Malik Hussain
Faculty of Agriculture and Life Sciences, Lincoln University
The use of probiotics as feed supplements is becoming an increasingly popular way to improve the health and productivity of livestock.
Probiotic feed supplements are difficult to use in agricultural settings mainly because of a lack of refrigeration facilities across the length of the supply chain.
This situation causes challenges in storing, retailing, delivering and administering probiotics as animal feed supplements.
As a result, it is important to understand the stability and viability of the probiotic microorganisms within them to successfully use probiotics as feed supplements.
The food microbiology group at Lincoln University investigated the status of the viability of probiotics in four products currently used on dairy farms in New Zealand.
The viability of cells in each product was assessed using live, dead, staining and total plate counts.
The total number of cells was measured using the qNanoTM technology of Izon, originally designed to count nano-particles.
The group used it to count the numbers of microbial sized objects or cells in each product.
The use of qNano technology showed its potential to measure microbial cells in the fermented products. Further investigation is needed to optimise conditions for applying qNanoTM technology in this area.
Interestingly, all probiotic feed supplements were found to have very similar numbers of total microbial cells.
However, million fold (106 cfu/mL) differences were observed in the numbers of live cells able to be recovered on culture plates from the four products tested.
Our findings showed that these probiotic feed supplements had huge differences in the number of live cells present in each product.
No tests on the efficacy of the probiotic feed supplements were made.
Some companies claim that the microbial metabolites produced during fermentation were responsible for health improvements of the livestock and, by implication, the probiotic microbes may not necessarily have to be viable to have a beneficial effect.
Our study shows that it is imperative for farmers to choose a specific product for a particular application within their farming system.
Food radiation detected in seconds
By Iain MacIntyre
Released for sale in August, the device can test about 200 cardboard boxes filled with food in just one hour. Tokyo-based Fuji Electric has unveiled a device which can detect radiation in foodstuff within 12 seconds and without the need to prepare samples or even remove the subject matter from its packaging.
The unit can test foods placed on its conveyor belt to dimensions of 500mm x 500mm x 1000mm. Its highly-sensitive gamma-ray detector tests for such elements as radioactive iodine and cesium.
Given the continuous nature of the operation and the avoidance of time-consuming and labour-intensive pre-testing preparations, Fuji Electric claims it has removed tens of minutes from the previous best testing process.
It is understood the device can test about 200 cardboard boxes filled with food in just one hour.
Released this August, with shipment scheduled to commence in early September, the ¥4.3 million (about NZ$66,000) unit is targeted to achieve 500 sales during the rest of this year.
The development has been necessitated by the fear of radiation contamination in Japanese food following damage to nuclear reactors during the recent earthquake and tsunami disaster. Fuji Electric says its ideal use is for testing grains, vegetables and meat at food production, handling and distribution centres.
Rugby World Cup pests
New Zealand’s commercial fruit and vegetable growers are concerned we’ve welcomed a variety of new pests into the country, along with rugby fans.
An investigation by TV3’s Firstline has revealed what all growers feared – that the Rugby World Cup has been used as a reason to significantly reduce New Zealand’s border protection.
More than 270,000 passengers have walked straight out of our international airports without having their bags x-rayed. Last month, half of the Trans-Tasman arrivals were not x-rayed.
“If we are simply doing this to save 15 minutes for rugby fans, then I really hope they’ve got this right,” HortNZ president Andrew Fenton says.
“Because the risk is enormous - $800 million alone, just in the Bay of Plenty, not to mention upwards of 5000 jobs lost.
“All it takes is one Queensland Fruit Fly, found in one monitoring trap, on one orchard. International markets will close to us, for at least a year, if not longer.
“This government initiative could turn out to be a very expensive decision.”
