Limonoids occur naturally only in plant species of the Rutaceae and Meliaceae plant families (Manners, 2007). Limonoids are highly oxygenated modified triterpenes that are biosynthesized from the acetate–mevalonate pathway in citrus fruits (Roy & Saraf, 2006). They occur in significant amounts as aglycones and glycosides in seeds and fruit tissues. Citrus fruits contain approximately 36 limonoid aglycones and 17 limonoid glucosides (Hasegawa & Miyake, 1996). Major citrus species accumulate limonin, nomilin, obacunone, and deacetylnomilin. Limonoid aglycones that cause bitterness in numerous citrus fruits are converted into tasteless limonoid glucosides during fruit maturation (Endo et al., 2002). Soluble limonin glucoside is the predominant limonoid glucoside present in citrus juices, and it occurs at an amount twice that of the other limonoid glucosides combined (Herman, Fong Chi, Ou, & Hasegawa, 1990). In contrast, citrus seeds constitute the only natural repository of limonoid aglycones (Vikram, Jayaprakasha, & Patil, 2007). The seeds contain limonoid aglycones in amounts up to 1% of their fresh weight (Hasegawa, Bennett, & Verdon, 1980). In citrus seeds, nomilin glucoside occurs at a higher concentration than that of limonin glucoside