Rectified concentrates, also termed 'musts' in the case of grapes, are partially purified fruit sugar syrups. Acids and colour are removed prior to concentration, with resulting rectified concentrates composed almost entirely of sugar syrup. Rectified concentrates are used as a source of fruit sugar in the manufacture of food products such as preserves, juices and ice creams as filling liquids in the packaging of fresh-cut fruit pieces and as blending stocks for carbonated drinks. Rectified grape must and apple and pear juice concentrates can potentially serve as a source of sugars to adulterate fruit juices.
Significant economic advantage can be gained by the fraudulent adulteration of pure fruit juices either by diluting or extending with cheaper ingredients. This type of fraud is illegal in the EU but can be difficult to enforce as the adulteration techniques used are designed to mimic the authentic product.
This project proposes two complimentary analytical approaches for determining marker compounds useful in verifying the presence of rectified concentrates in fruit juice.
CSL previously identified oligosaccharide marker compounds ( project Q01041), thought to be formed during the rectifying process, in apple and grape rectified juice concentrates that are not present in other fruit juices. Oligosaccharide profiles will be recorded for a range of authentic rectified and other fruit juice concentrates. The amount of adulterant that can be detected will be determined by mixing proposed adulterants with authentic materials. The method will be tested by blind analysis of mixtures. It is intended a number of commercial products will be examined to test the applicability of the method to real samples.
The second approach involves method development for chemical profiling of juices to detect unexpected or unpredicted changes. The aim of this pilot study is to determine chemical differences between rectified juice concentrate and the fruit juice in the natural state without any preconception of what compounds should be targeted and then to locate and identify the component responsible for the difference(s).
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.