IMPACT OF GEOGRAPHICAL LOCALIZATION ON SEED MORPHOLOGY, OIL CONTENT AND FATTY ACID COMPOSITION OF MADHUCA LONGIFOLIA GROWN IN SRI LANKA

Abstract

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M. longifolia (Sapotaceae) is a locally available plant in Sri Lanka which is valued for its seeds as a source of edible oil. Past studies revealed that the quantity of oil in seed is over 50% of its weight, yet ; this remains as an under-utilized source of oil. The aim of this study was to identify the variation in ‘ morphology of seeds, variation in fatty acid profile and in oil content of M. longifolia seeds from different agro-ecological zones in Sri Lanka. Simultaneously, to determine the relationship of;dil content and fatty acid profile with some geographical factors. Dried, fallen seeds were collected from . 1 randomly selected 16 plants (4 from each zone) representing four agro-ecological zones in Sri Lanka based on the availability of plant. They were low country dry zone (LD), low country wet zone (LW),‘ ‘ low country intermediate zone (LI) and mid country intermediate zone (MI). The length, width and; the weight of seeds were determined as morphological characteristics. Oil from seed kernel was;; • extracted using Soxhlet method (AOAC, 1990) using n-Hexane (bp. 65-70° C). Fatty acid meth^J |; esters were prepared and identified using GC-MS. Significant differences (P<0.05) were obseivei;:^ within agro-ecological zones on seed morphology (in terms of all 3 tested characteristics). Results; ranged from 2.73-3.43 cm for length, 1.06-1.30 cm for width and 0.93-1.40 g for weight..Significant-, differences were resulted (P<0.05) in oil content also (50.07-53.85%) among agro-ecological zones." As the major fatty acids, Oleic, Stearic, Palmitic and Linoleic were resulted in all four agro-chmatic;;,;---: zones. The total saturated fatty acid content (C18:0, C16:0, C14:0, C17:0, C19:0, C22:0, 024^0,? . ; j C26:0, C20:0 and C8:0) varied from 40.87-47.20%. However the total unsaturated fatty acid content! , (C l6:1, C l8:1, C l8:2, C20:l) was observed in the range of 49.6-53.86% (TMXJFA+TPUFA).^Tt^^;;. highest total fatty acid content was recorded in low country intermediate zone and the lowest in mid ’■, country intermediate zone. A considerable variation was shown among the individual fatty acid,^ ■ contents obtained from different agro-climatic zones. Oil content and the fatty acid com position were ^, . not correlated with the studied geographical parameters (altitude, longitude and latitude)