Vanilla extract, HPLC analysis

The high demand for authentic vanilla extract as a flavoring agent has resulted in frequent attempts at adulteration. An HPLC method for the quantitation of coumarins as an adulterant in a variety of vanilla flavorings, using a 10-yu.m /xBondapak Cl8 column with MeOH-HzO (40 60, v/v) as the mobile phase, was proposed (156). Phenolic analysis could be used further for the detection of mixtures of fruits in jams (157). The phenolics present in different commercial jams of apricot, plum, peach, strawberry, sour orange, apple, and pear have been compared and the characteristic compounds for each different jam identified for potential use as marker compounds. 

Waliszewski et al. (2007b) described a simple and rapid HPLC technique for vanillin determination in alcohol vanilla extract, and the method has been applied successfully for the determination of vanillin in some commercial extracts for routine analysis. de Jager et al. (2007) developed a LC-MS method for the determination of vanillin, coumarin and ethyl vanillin in vanilla products using LC-electrospray ionization in the positive ionization mode. The limits of detection for the method ranged from 0.051 to 0.073 pg/ml. 

Lamprecht, G., Pichlmayer, F. and Schmid, E.R. (1994) Determination of the authenticity of vanilla extracts by stable isotope ratio analysis and component analysis by HPLC. Journal of Agricultural and Food Chemistry 42, 1722-1 72 7. 

These detectors are commonly used in HPLC analysis. The absorption of the substances in the eluate by a specific wavelength normally between 190 and 700 nm is proportional to their concentration. This technique is widely used for quality control of flavourings, e.g. for the quantification of the vanillin/p-hydroxybenzaldehyde ratio for natural vanilla products, for the determination of caffeine in extracts and drinks, or for the detection and quantification of restricted ingredients such as quassine, coumarin or p-asarone in natural extracts [11-12[. 

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