PHYSICOCHEMICAL PROPERTIES OF CUCUMIS MELO VAR. INODORUS (HONEYDEW MELON) SEED AND SEED OIL

ABSTRACT

Cucumis melo var. inodorus seeds were found to contain 4.5% moisture, 25.0% crude fat, 25.0% crude protein, 23.3% crude fiber, 2.4% ash and 19.8% carbohydrate. The iodine and saponification values, and unsaponifiable matter and free fatty acid contents of freshly extracted honeydew melon seed oil were 153.4 g I₂/100 g oil, 210.2 mg KOH/g oil, 0.9 and 2.5%, respectively. The oil had a color index of 1.6Y + 0.4R, and had 10 fatty acids, of which 86.1% were unsaturated. Linoleic acid predominated with 69.0% followed by oleic acid (16.8%) and palmitic acid (8.4%). LLL (24.9%), OLL (21.5%), PLL (15.9%) and POL (12.4%) (where L, O, P and S denote linoleic, oleic, palmitic and stearic acids, respectively) were the major triacylglycerols present. The melting and crystallization temperatures were −5.12 and −59.01C, respectively. Electronic nose analysis showed the presence of more volatile compounds compared to refined sunflower oil, an oil rich also in linoleic acid.

PRACTICAL APPLICATIONS

In Malaysia, honeydew melon (Cucumis melo var. inodorus) seeds are normally treated as waste products. In this study, honeydew melon seed oil was found to have a potential to become a new edible oil source as it contained a level high in polyunsaturated fatty acids.