Changes in Acyl Lipids of Food

The role of waxes is to protect the surface of plant leaves, stems and seeds from dehydration and infections by microorganisms. Waxes are removed together with oils by solvent extraction of nondehulled seeds. Waxes are oil-soluble at elevated temperatures but crystalhze at room temperature, causing undesired oil turbidity. Ceryl cerotate (ceryl alcohol esterified with cerotic acid, C25H51COOH) 

Waxes are also components of the mass used to cover fruit to protect it from drying out. 

Waxes are present in fish oils, especially in sperm whale blubber and whale head oil, which contain a reservoir of spermaceti wax. 

Plant epidermal cells are protected by a suberized or waxy cuticle. An additional layer of epicuticu-lar waxes is deposited above the cuticle in many plants. The waxy cuticle consists of cutin. This is a complex, high molecular weight polyester which is readily solubilized in alkali. The structural units of the polymer are hydroxy fatty acids. The latter are similar in structure to the compounds given in 3.7.2.4.I. A segment of the postulated structure of cutin is presented in Fig. 3.16. 

The higher alcohols, 16 0, 18 0 and 18 1 (9), form mono- and diethers with glycerol. Such alkoxy-lipids are widely distributed in small amounts in mammals and sea animals. Examples of confirmed structures are shown in Formula 3.48. 

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