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Gelatine is a protein product derived from collagen, which is made from either from animal bones or skin. Gelatine is an extremely versatile low cost food ingredient, which is used as a thickener, stabiliser and gelling agent in many food products, and also a clarifying agent in fruit juices and beer. Gelatine, along with other animal products cannot be used in food items described as ‘suitable for vegetarians’.
The current method of measuring gelatine relies on the determination of hydroxyproline as a marker for gelatine. However, this amino acid is also present in the cell wall of some plant foods and therefore the current methodology is unsuitable for accurate determination of gelatine in plant food matrices. <P>
This research project developed an improved selective extraction method to extract gelatine in plant based products, and forms part of a programme of work to enable the detection of animal ingredients in vegetarian foods
Research Approach: Plant cell wall glycoproteins and gelatine differ in their water solubility properties. The method developed in this project will utilise this difference and use a hot dilute acid extraction followed by a tannic acid precipitation of the gelatine. Recoveries using authentic gelatines and different plant food matrices will be checked to validate the method and produce a SOP (standard operating procedure).
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Results and findings: A method to selectively extract gelatine from other hydroxyproline-containing compounds has been developed. The method involves extracting gelatine from food matrices using hot acid, and precipitating gelatine using tannic acid. The method is very sensitive and has a limit of detection of 0.19% gelatine. The final report with results is available on Foodbase. A SOP has been produced which we plan to make available on the website.
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Plant cell wall glycoproteins and gelatine differ in their water solubility properties. The method developed in this project utilise this difference by selectively extracting gelatine from other hydroxyproline-containing compounds. The method involves extracting gelatine from food matrices using hot acid, and precipitating gelatine using tannic acid. The method is very sensitive and has a limit of detection of 0.19% gelatine. Recoveries using authentic gelatines and different plant food matrices were checked to validate the method and a standard operating procedure (SOP) has been produced which we plan to make available on Foodbase.
<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>.