ALDEHYDE GLYCOSIDES

Vanilla

B.O. Vanilla panifolia (Mexican or Bourbon Vanilla)

Vanilla tahitensis (Tahiti vanilla)

Family Orchidaceae.

P.O. Vanilla beans (carefully cured fully grown but unripe fruits).

Production and Commerce: -

The plants are perennial climbing epiphytes which arise from soil roots by means of a fleshy dark green sucklent stem that reaches it self to the trunk and branches of trees by means of aerial rootlets.

The plant is indigenous to Eastern Mexico and cultivated in tropical countries like Mauritius, Sri Lanka, Indonesia, Java and Thailand, where temperature does not fall below 18 C and where humidity is great. Plant is usually propagated by means of cuttings and after 2-3 years reaches the flowering stage and continues to produce fruit for 30-40 years.

The fruits are collected as they are ripened to a yellow colour, 6-10 months after pollination and are cured by dipping them in warm water and repeatedly sweating them between woolen blankets in the sun during the day and packing them in wool covered boxes at night. This requires about two months during which the fruit loses 70-80 % of their original weight and takes on the characteristic colour and odour of the commercial drug. The fruits are then graded, tied into bundles of about 50-75 and sealed in tin container for shipment.

Characteristics: -

Vanilla pods are 15-25 cm in length, 8-10cm in diameter and somewhat flattened.

The surface is longitudinally wrinkled dark brown to violet black in colour and frequently covered with needle like crystals of vanillin. The odour and taste is characteristically aromatic.

Constituents: -

Before curing, green vanilla contain two glycosides

Glucovanillin (vaniloside)

Glucovanillic alcohol

During curing these two compounds are acted upon by an oxidizing and a hydrolyzing enzyme, which occur through out the plant. Glucovanillin upon hydrolysis yield glucose and vanillin where as glucovanillic alcohol yield on hydrolysis glucose and vanillic alcohol.

Vanillic alcohol by oxidation converted into vanillic aldehyde (vanillin).

Vanillin: -

Vanillin consists of fine white or light yellow crystals having aromatic odour and taste. It is slightly soluble in water and glycerin but freely soluble in alcohol chloroform and ether.

Uses: -

It is mainly used as flavouring agent. Vanilla pods are widely used in confectionery and perfumery.