December 2014

  Monthly archive

Nanotechnology in the food industry

Craig Duckham FIFST reviews the impact of nanotechnology on the food industry and identifies current and future application areas.

In-pack ozone sterilisation

Extending the shelf life of packaged food products is an effective way of reducing food waste. Hugh Potts, founder and Chief Scientific Officer of Anacail, a spin-out company from Glasgow University, describes the advantages and applications of the company’s new in-pack ozone sterilisation technology.

Microwaves for safer, more nutritious food and drink

Douglas Armstrong and Sue Gordon of Advanced Microwave Technologies describe the benefits of Microwave Volumetric Heating in food processing.

Stable isotope analysis for authenticating food origin

Kim Matthews, Head of R&D for EBLEX (the Division of the Agriculture and Horticulture Development Board responsible for beef and sheep in England) explains how stable isotope analysis can be used to verify the origin of pork and a wide range of other food products.

Strategies for food traceability

Richard Tipper, chairman of Ecometrica, outlines the current strategies for food traceability and considers the potential for using geospatial information to improve understanding of changes in the supply chain.

Regulatory challenges for food authenticity

Preventing fraudulent practices is an important and challenging issue facing regulators, enforcers and the food industry. Michelle McQuillan, Andy Furmage and Lucy Foster of the Food Science Evidence Team, Food Policy Unit, Department for Environment, Food and Rural Affairs (Defra), discuss the challenges faced by Defra’s Food Authenticity Programme.

Food Authenticity Programme
Food fraud is high on the Government’s agenda, particularly in the wake of the horsemeat incident of 2013 and the recent publication of the Elliott Review into the Integrity and Assurance of Food Supply Networks.[1] Maintaining the integrity of the food chain and ensuring its resilience are key drivers for Ministers. Following the horsemeat incident there was a loss of consumer confidence in food and the Government is committed to restoring and improving confidence and ensuring a level playing field for legitimate businesses. Defra’s Food Authenticity Programme plays a key role in safeguarding our food by ensuring consumers are not misled. This Programme has been in existence for over 20 years and prides itself on using cutting edge science and technology to tackle food misdescription and to verify the accuracy of food labelling.

The Programme is centred on the development of enabling methodology to detect fraud, helping transfer these methods for use in UK food law enforcement and the provision of a sound scientific evidence base to support Government policy on composition and labelling. The Programme is supported by two independent expert groups: the Authenticity Steering Group (ASG), which advises Defra and the FSA on the overarching research priorities, and the Analytical Methods Working Group (AMWG), which advises on the science and methodology and provides a quality assurance function to ensure methods being developed are fit for purpose. Both groups comprise representatives from the food industry, enforcement bodies, consumer organisations and academia to ensure balance and focus.

Food fraud drivers and challenges
Food fraud is mainly economically motivated for financial gain. It can have significant negative effects on both consumers and legitimate businesses. It is also driven by factors such as volatility in food prices, the availability of raw materials and ingredients, the economic climate, regulatory developments and wider environmental impacts.

The main Government policy drivers are focused on ensuring that consumers are not being misled, making sure that businesses have a level playing field and that enforcers are equipped with the tools needed to ensure compliance with the law. To achieve this the Food Authenticity Programme needs to keep one step ahead of the fraudsters by looking at new and innovative means to detect and prevent food fraud by the use of cutting edge research and technology.

Types of misdescription
Food fraud covers a broad spectrum of labelling misdescription issues including misleading claims or false declaration about a product, adulteration with a different ingredient and false declaration about the origin, treatment or method of production of a product. Examples of misdescription include undeclared addition of water in chicken, hazelnut in olive oil, water or colours in fruit juices, passing off cheaper versions of a food for those that command a premium, e.g. specific breeds, basmati rice, durum wheat, fish (cod, haddock). False declaration could be passing off previously frozen poultry as fresh or ‘farmed’ for wild fish or ‘organic’ for conventional produce. Detecting such misdescription presents a plethora of technical challenges in terms of the analytical tools needed to verify food description. Ensuring that methods are fit for purpose to support food law enforcement is critical if they are to be used by enforcers to ensure food business operators are complying with food legislation.

Technical challenges
There are many practical difficulties in developing food authenticity methods one of the most fundamental being the ability to find a marker that characterises the food, one of its ingredients, the adulterant(s) or the processing, production or geographic origin. The availability of authentic samples and accessibility to curated references are challenges which can often impinge on the success of a method. Because in many cases the fraudulent practice is linked to a legal requirement, standard or guidance, conclusions must be beyond reasonable doubt. However, data interpretation is made against a background of analytical uncertainty, food matrix effects and natural variation.

DNA methods have undoubtedly proved successful in the Programme but there is still a need to overcome specific challenges around analytical uncertainty, quantitation, matrix complexity and processing conditions. The most pressing of these is probably the need for quantitation at much lower levels than has been previously carried out, reflecting the increase in sensitivity of analytical methods to detect food fraud, resulting in much lower limits of detection.

Following the horsemeat incident, there was a need to be able to accurately quantify the presence of adulterants e.g. meat species at around the 1% level and lower. The Programme has funded work to look at levels of cross contamination of meat species produced according to good manufacturing practice.[2] This work concluded that the presence of a potential adulterant above the level of 1% w/w should be considered as deliberate addition and adventitious contamination cannot be used to account for its presence. The challenge for the future is to be able to develop methods which can
routinely detect adulterants at 1% or lower.

Despite the challenges discussed above, substantial progress has been made in tackling food fraud and misdescription in a number of areas. The Programme has commissioned over 150 projects to date, covering a wide range of techniques (e.g. Stable Isotope Ratio Analysis (SIRA), proteomics, genomics, metabolomics etc.) across a host of food and beverage matrices and production methods. It has successfully developed over 30 methods which have been converted to standard operating procedures and these have been made available for use by analytical laboratories. Details of the projects are available on the Defra R&D website [3] and in over 50 scientific papers in peerreviewed journals.

Methodology – delving into the tool box
Figure 1. The Food Authenticity Analytical ToolboxWell-established techniques can be used for novel applications, such as chemical analysis and microscopy, to identify mechanically separated meat, as well as more cuttingedge technologies like genomics in species identification. Recently there has been a move away from traditional chemical type analysis to making use of a new toolbox of techniques outlined in Figure 1, many of which are employed in forensic science.

The methodology can be broadly divided into four main types: chemical, physical, DNA and proteomic based methods. Chemical methods, such as Stable Isotope Ratio analysis (SIRA), have proved successful in determining the geographic origin of products or the method of production. More traditional physical methods, such as microscopy, are being used to identify mechanically separated meat (MSM) and to screen for durum wheat and basmati rice adulteration.

DNA-based methods have proved to be well suited to species identification i.e. meat, fish and fruit speciation. Some of these DNA methods (eg RT-PCR) have been transferred to simpler platforms, such as microfluidic capillary electrophoresis, known as ‘lab-on-a chip’, which has helped encourage uptake of Figure 2. Lab on a chip technologythese methods by official food control laboratories. The lab on a chip format (see Figure 2 opposite) was initially trialled on fish but has now been extended to more than 100 species, including canned fish, basmati rice, orange juice, durum wheat and potatoes and has made life much easier for public analysts.

More recently, proteomic methods have been used to look at complex and highly processed meat products and identify peptide markers for meat species, offal tissue and the species origin of gelatine in highly degraded samples. These methods have also proved very successful in determining the presence and species of water-retention and chicken plumping agents and are now routinely used by UK public analysts and the European Commission. The Programme is also looking at some more cutting edge methodologies that include metabolomics to detect markers for MSM and the characterisation of microbial communities to indicate origin, for example in oysters.

Meat Speciation
The Programme has developed and optimised methods to detect many different meat species ranging from rare breeds of cattle and pigs to exotic meats (bush meat, wild boar and others). These have largely exploited DNA-based techniques to identify meat species and more recently to achieve better quantitation at lower levels. Over the last 18 months much effort has been focused on improving and quantifying the detection of horsemeat; quantitation by DNA has inherent challenges relating to how the results are expressed (e.g. by copy number or on a weight basis). Work on validating real time PCR method for the quantitation of horse DNA in beef has proved successful and this has been extended to investigate the potential of the method to quantify horsemeat in complex food matrices and to evaluate the measurement uncertainty around the 1% level. [4]

Work has also been funded to evaluate and compare three DNA-based methods used by public analysts for the determination of horse meat in beef samples. Good comparability between the methods was achieved, showing them to be capable of reaching a detection limit of less than 0.1% w/w raw horse-meat in raw beef if quality procedures and Good Laboratory Practice (GLP) were adhered to. This work gives confidence in UK horsemeat detection methods. [5]

DNA testing methods are notably more difficult in highly processed foods due to the impact of heat denaturation on DNA integrity. Consequently work is underway on the development of a proteomics method for meat speciation in heavily processed foodstuffs. The aim is to identify proteins or peptides which can survive heavy processing and which contain amino acid sequences that are unique to different species of meat-producing animals and therefore suitable for meat speciation. Proteomics has the advantage of allowing the simultaneous detection of multiple markers, thus offering scope for untargeted detection of multiple meat species.

Immunological techniques have been used to develop a new method to detect offal species (heart, kidney, liver and lung) in meat products. This is based on ELISA technology using a Western Blotting technique with confirmatory analysis using protein mass spectrometry. Road testing of the method on commercial samples will determine if the method is fit for purpose so that it can be rolled out for use by enforcement authorities.

Geographic Origin Stable Isotope Ratio Analyses (SIRA)
Figure 3. SIRA discrimination of beef origin (reproduced with kind permission from Dr Simon Kelly)Products from a specific origin or produced using a particular production method are often sold at a premium providing an incentive for substitution with a more cheaply produced alternative. Food labelling legislation on country of origin means there is a need to be able to verify origin claims analytically to enforce the law. With this in mind the Programme has funded a number of projects to look at SIRA techniques for the verification of both geographic and method of production origin. Issues that have been addressed using this approach include verification of wild and farmed fish, verification of corn-fed chicken and organic vegetables and verifying the geographic origin of beer. Figure 3 shows the discrimination of British beef from Brazilian beef on the basis of stable isotope analysis, recognising that labelling of beef origin is mandatory.

Figure 4. SIRA discrimination of British beefFurther work to see whether beef from different regions of the UK could be identified to verify labels, such as Scotch, Welsh and Orkney Beef, was more challenging as might be expected. There was more overlap between the authentic samples particularly from England and Wales (Figure 4). The techniques were most useful when applied to specific origin questions such as distinguishing English beef from Scottish beef or Orkney beef from other Scottish beef. There are some limitations in that the method cannot as yet be used to identify unknown samples (of no geographic indication) and mixed or processed meat products.

A recent small scale study by Defra and the FSA used SIRA to verify the UK origin claims of 96 samples across six foods (beef, pork, lamb, apple juice, tomatoes and honey). [6] The study did not identify any cases of food on sale with misleading country of origin claims and showed that the technique was a potentially useful screening method which could be followed up with traceability checks.

Challenges for the future
The Food Authenticity Programme will continue to address the need for practical, transferable, reliable and cost-effective methods for use by enforcers to tackle new food authenticity issues and to ensure its role as a world leader in food authenticity method development. The ultimate aim is to work with industry, enforcers and experts to protect the consumer and the integrity of our food while ensuring a competitive and resilient UK food economy.

The Food and Environment Research Agency (Fera), an executive agency of Defra, is a key partner in the European Commission’s €12m, 5 year, EU Food Integrity Project which began in 2014. It will be working to exert its influence and galvanise Member States and experts to develop more harmonised approaches to method development and testing, drawing on the importance of accessibility to both reference materials and curated reference databases.

Looking ahead, the Food Authenticity Programme will maintain its investment in cutting edge techniques and continue to maximise the impact of science by seeking collaboration and developing new partnerships wherever possible. It will be focusing on more portable, rapid authenticity tools, such as simple and fast screening techniques for use in the field, but these will need to complement tools which are defensible in court to support food law enforcement activity. More resources will also be invested in approaches which use non targeted multi-analyte platforms across a range of foods. The need for better availability and accessibility to authentic reference materials will be key to achieving future success. More work on reducing measurement uncertainty in PCRbased methods and addressing the variability of DNA extraction and amplification will be needed if its use as a rapid tool is to be realised. Furthermore work on the potential use of novel quantification methods, such as digital PCR, quantitative PCR and protein mass spectrometry, is being explored while the use of genomics, proteomics and metabolomics also hold potential for the future.

Michelle McQuillan, Andy Furmage and Lucy Foster are in the Food Science Evidence Team, Food Policy Unit, Department for Environment, Food and Rural Affairs (Defra), Area 3A, Nobel House, c/o 17 Smith Square, London, SW1P 3JR, UK
Tel: +44 (0) 20 7238 4352
Email: michelle.mcquillan@defra.gsi.gov.uk
Web: www.gov.uk/defra

References

1. Elliott review: https://www.gov.uk/government/news/consumer-confidence-to-be-strengthene...

2. Cross-contamination levels in processing plants - FA0137

3. http://randd.defra.gov.uk/

4. Method development for the quantitation of equine DNA and feasibility of establishing objective comparisons between measurement expression units (DNA/DNA compared to w/w tissue) - FA0135

5. Eloise Busby and Malcolm Burns (2014) Method Verification of the LOD Associated with PCR Approaches for the Detection of Horse Meat, Journal of the Association of Public Analysts (Online) 2014 42 001-017

6. Food Standards Agency, Study on geographic origin, July 2014

Delivering a food safety culture

Sterling Crew, Vice President IFST and Head of Technical at Kolak Snack Foods Ltd, explains the importance of developing a positive food safety culture.

Ralph Early, Professor of Food Industry at Harper Adams University, discusses the changing attitudes to food in society and explains the initiatives that Harper Adams is undertaking to raise awareness about the interesting and varied career opportunities in the food industry and to give school pupils hands-on experience.

Culture change

Professor Chris Elliott’s long awaited report on food fraud was published in September 2014. The report identifies eight recommendations or ‘pillars of food integrity’ that are interdependent.

UK food security

The National Farmers’ Union (NFU), the Crop Protection Association (CPA) and the Agricultural Industries Confederation (AIC) have commissioned farm business consultants Andersons to produce an independent report to look at the economic impact of crop protection technologies on UK agriculture and the wider economy.

Making sense of sugar

A new campaign was launched in September by AB Sugar to help inform and educate people about sugar and the role it can play as part of a healthy, balanced diet, and to help people make better informed choices about what they consume.

Sustainability leaders

For the second year running, Unilever has emerged as the sustainability leader in the Tomorrow’s Value Rating 2014



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