Vanillin

Chemical Properties

Colorless to pale yellow liquid with lemon, citronella, and rose aroma. Exists in three optical isomers: d-, l-, and dl-. D-Citronellal is abundant in essential oils and is a major component of citronella oil and eucalyptus oil, with a boiling point of 203–204°C, relative density (d₄²⁰) 0.8510, optical rotation [α]D¹⁸ +10°18′, and refractive index (D²⁰) 1.4467. L-Citronellal is found in lemongrass oil, with a boiling point of 206°C, relative density (d₂₅²⁵) 0.8567, refractive index (nD²⁰) 1.4491, and optical rotation [α]D -3°. It readily cyclizes to form menthol in acidic media. Flash point 77°C. Soluble in ethanol and most non-volatile oils, slightly soluble in volatile oils and propylene glycol, insoluble in glycerol.

Uses

GB2760—96 stipulates it as an permitted edible flavor. Mainly used in the formulation of citrus and cherry-type flavors.

Uses

Primarily used as a raw material for the synthesis of citronellol, hydroxycitronellal, menthol, etc. It can be used in small amounts in low-grade lemon, cologne, magnolia, lily of the valley, honey, and fern-type flavors, mainly for its prominent grassy-green effect.