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Food Safety Application Notebook


The Dionex Food Safety Application Notebook, a 170-page plus compilation of food safety applications in an easy-to-use PDF, is available on the Dionex website. Concerns about food safety have risen to the forefront with the frequent exposés of dangerous and, sometimes, deadly contamination in the global food supply chain in the last few years. Products are grown and processed in widely differing environments under a variety of regulatory frameworks, travel thousands of miles, are kept in various storage conditions, experience temperature fluctuations that may affect shelf life, and are handled by many different people. At any point in this process, products can be contaminated or may become unfit for consumption. Dionex has been working with industry and regulatory agencies to develop numerous extraction, sample preparation, IC, and HPLC solutions for the determination of a broad range of food contaminants so that many of these food contaminants can be isolated and identified reliably and quickly before they reach the table.


The Dionex Food Safety Application Notebook lists and describes food safety applications grouped by contaminant type: agricultural, chemical, environmental, food additive, and food processing. Applications include pesticides through acrylamide in foodstuff. The notebook combines applications notes on extraction and analysis by HPLC or IC and includes a Column Selection Guide.


Circle no. 549 Help Rather than Hype to those with Food Allergy


When it comes to food allergies and intolerance, the advice available to the public ranges from the dependable to the downright dangerous. Recognising the need to ensure that the public receive consistent and reliable advice, The British Dietetic Association (BDA) has collaborated with the Food Standards Agency and five other allergy and nutrition organisations (Allergy UK, the Anaphylaxis Campaign, the British Nutrition Foundation, Coeliac UK and Foods Matter) on a just published advice leaflet for people who have been newly diagnosed with a food allergy.


The leaflet, ‘Buying food when you have a food allergy or intolerance’, guides people with a food allergy or intolerance, including coeliac disease, through the steps to remember when buying food and when eating out. The topics covered include checking the label on pre-packed food; what to look out for when foods aren't pre-packed; talking to restaurant staff about your allergy; what to watch out for when using self-service restaurants.


The leaflet also reassures people that there is no need to worry that being unable to eat a particular food will harm health and reminds them that it is the overall balance of their diet that matters. Dietitian Heidi Ball who contributed to the leaflet said ‘If you can’t eat certain foods it’s a good idea to choose other foods you can eat to give you the nutrients you need. For example if you are cutting out dairy, you’ll need to make sure you include other sources of calcium. Remember, don’t cut major food groups out of your diet without medical advice.’


Circle no. 550


Food Safety Agency Praise Novel Blender Smasher®


Consumers encounter beverages packaged in plastic (polyethylene terephthalate) bottles daily. The launch of the new packaging material provision clearly influenced the further purpose of the plastic bottles after their use as packaging. The waste manager is now confronted with the task of processing these materials. For this purpose plastic bottles are shredded. This process creates pieces (so called flecks) of an average size of 3 x 12mm and also a very fine dust. With a suitable cleaning process, the shredded product is washed absolutely clean.


, the novel food sample paddle blender from AES Chemunex, has been evaluated by the French agency for food


safety (AFSSA) in a comprehensive study on 150 samples with two main objectives: test the contamination homogeneity of a chicken carcass in order to validate its use as a sample to make the comparative study between conventional and Smasher® blenders; and test the Smasher® contaminated samples.


at different blending durations vs. conventional blending device with homogeneously


The conclusion underlines Smasher's outstanding efficiency for the food sample microbial analysis preparation: “The results obtained from 150 samples for each condition showed that the Smasher®


of the conventional blender tested at a 60 second blending time. The statistical analyses made showed that the differences between the three blending times were not significant."


Circle no. 551 Cranberry Juice Fails to cut it


Current clinical evidence for using cranberry juice to combat urinary tract infections is 'unsatisfactory and inconclusive', according to Raul Raz. "An apple a day..." Not all medical problems require a state-of-the-art solution, and it would be nice to think that products from the corner shop could treat a widespread and uncomfortable ailment. Cranberry juice and related products have been touted as a simple solution for urinary tract infections, but Raul Raz, a member of F1000 Medicine, finds little to support this claim.


Urinary tract infections (UTIs) are a common complaint. Between 10% and 20% of women will suffer a UTI at least once, and a third of these will experience it recurrently. Some recent studies support the use of cranberry as a preventative, but Dr Raz, Director of Infectious Diseases at the Technion School of Medicine in Israel, and his associate Faculty Member, Hana Edelstein, advise the medical community that ‘cranberry should no longer be considered as an effective [preventative] for recurrent UTIs’.


Cranberry contains hundreds of compounds, and it has been difficult to determine which might be responsible for any therapeutic effect, hindering its adoption. Raz and Edelstein point to differences in clinical trial design and the lack of standardisation for doses and formulation. There is a range of potential side effects including stomach upsets and weight gain. Cranberry can also interact badly with other medicines such as Warfarin, commonly used to treat heart disease. In any event, up to 55% of patients discontinue cranberry therapy after a short time. It would seem that the public have already voted with their feet.


Circle no. 552 Multi-Residue Analysis of Pesticides in Rice


Thermo Fisher Scientific, Inc announced a new method that enables rapid and accurate identification and quantification of pesticides in rice. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method takes advantage of the Thermo Scientific ITQ 700 GC-ion trap mass spectrometer and the Thermo Scientific FOCUS GC gas chromatograph to increase speed and improve sample preparation. The application note describing the method, entitled ‘Multi-residue Pesticide Analysis in Rice by a Modified QuEChERS Extraction and Ion Trap GC/MSn Analysis’.


Recently formulated pesticides are smaller in molecular weight than their predecessors and are designed to break down rapidly in the environment. As a result, more careful consideration must be placed on the sample preparation for extraction and the instrument parameters for analysis in order to successfully identify and quantify these compounds in foods. The QuEChERS sample preparation method, which is already shown to simplify the determination of pesticides in fruits, vegetable, grains and herbs, can now be used to successfully prepare rice extracts before ion trap GC/MSn analysis.


The study was performed by pairing the ITQ 700 with the Thermo Scientific FOCUS GC gas chromatograph to establish the linear ranges, quantitation limits and detection limits for a list of pesticides that are commonly used on rice crops. Samples were prepared in matrix using the QuEChERS sample preparation method, which involves extraction, clean up and solvent exchange processes. The ITQ 700 GC-ion trap MS demonstrated excellent accuracy at low concentrations of 33 pesticide residues analysed in rice. The optional MSn mode was shown to offer enhanced selectivity over scanning modes such as full scan and selected ion monitoring (SIM). This enables users to identify, confirm and quantify the existence of pesticides in a single analytical run. In addition, the daily analysis of endrin, DDT and their breakdown products confirmed the system’s ability to analyse active compounds without the need for continual, expensive and time-consuming maintenance.


Circle no. 553 tested at 15 and 30 seconds blending times made it possible to obtain results similar to those


The separation from other plastics, for example PP (polypropylene) or PE (polyethylene) from which mostly the screw tops are made, is accomplished in the sink and suspension method with a density separation. After the drying process the paper labels may also be removed by the blowing off process. The flecks are sold in this state by the recycling firms. For further processing the fine share must be extruded and the emerging granulates are then also sold.


The production of higher quality products from this recycled material requires a broad analytical evaluation. For this purpose a comminution of the flecks as well as the granules is necessary. The evaluated parameters are among other factors - the degree of polymerisation and the colour. A statement about the degree of polymerisation and therefore a mechanical or thermal damage is obtained via the determination of the melt-flow-index.


This determination is a wide spread method in the field of chemical polymers. The measured value depends on the particle size. The colour is determined via the white level measurement. But the measured data is greatly dependent on the reflected light and therewith also on the particle size. Therefore, prior to the determination of the melt-flow- index and before the measurement of the white level, the samples always must be prepared in a reproducible manner.


Utilised for the defined preparation of the samples is the variable speed rotor mill PULVERISETTE 14 from Fritsch, inclusive the impact rotor with 12 ribs and a sieve with 1mm mesh width. The rotational speed control for the cutting rotor is for the achievement of the reproducible results immensely important.


Mostly with polyethylene terephthalate Fritsch recommend working with 16.000 r/pm. Tests by the users in this concrete case lead to the settings of lower rotational speeds. Dependent on products and testing parameters, the optimum rotational speed was set between 10.000 and 14.000 rpm. These low rotational speeds of the rotors minimise the mechanical, respectively the thermal demands during the comminution. Consequently a lower throughput is to be expected.


Circle no. 554


Plastic Beverage Bottles


Spotlight


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