Limonoid Aglycone Analysis

A variety of methods have been proposed for the detection and quantification of bitter limonoids in citrus. Most methods were developed specifically for the quantification of limonin in citrus juices. The early techniques included colorimetry, fluorimetry, and gas chromatography. 

The colorimetric method (Wilson and Crutchfield 1968) and the fluorometric method (Fisher 1973) involve the chemical derivation of the limonoids. However, the reactions are not specific for limonin, and these techniques depend on isolating limonin from interfering compounds. Kruger and Colter (1972) developed a derivitization procedure to allow for the non-volatile limonin in citrus juices to be analyzed by gas chromatography. 

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In the food industry, high-performance liquid chromatography (HPLC) is the most widely used technique for the determination of limonin levels in citrus juices, since it is accurate and reliable. Most of the HPLC methods developed are for the analysis of limonin in citrus juices. These methods may not work for other bitter limonoid aglycones and/or tissues. 

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