Ester of fatty acid and monohydric alcohol with high molecular weight is called wax. Carbon numbers of fatty acids are 14-36 and carbon numbers of alcohols are 16-36. Waxes are insoluble in water, but soluble in organic solvents. It is chemically inert. Remains solid at normal temperature. The stems, leaves, flowers and fruits of plants contain wax. Carnoba wax is produced from the Brazilian palm tree. Different types of wax are – lanolin, beeswax, feather wax, hair wax, bewax, carnoba, sebum, cerumen, suberin etc.
Properties of wax
(i) Wax is colorless and odorless.
(ii) Waxes are insoluble in water, but soluble in organic solvents.
(iii) It is chemically inert.
(iv) Wax remains solid at normal temperature.
(v) It contains saturated fatty acids.
(vi) It is water repellent.
(vii) Its melting point is higher than fat.
Functions/importance of wax
(i) Wax acts as a water resistant layer on the stem, leaves, fruits and flowers of plants.
(ii) Wax acts as a preservative in plant organs.
(iii) Candles are made from wax.
(iv) It is used in cosmetic industry.
(v) Waxy feathers and feathers are water resistant.
(vi) Reduces waxy sensation on leaves and young stems.
(vii) Cutin and suberin coat are formed in the cell wall. Cutin and suberin are waxy substances.
(viii) It is used in fruit preservation.