Biochemical Characteristics of some edible and non-edible fats and oils of Bangladesh

Abstract

A comparative study was made on some characteristics of edible and non-edible fats and oils available in Bangladesh. Comparison was made between the purified and non-purified forms of the same edible fats and oils. The parameters based on which the nutritional value of all the fats and oils were determined were iodine value, saponification value, acid value and fatty acid composition. In the case of edible oils, soybean (Postman) had the highest iodine value (149.49) whereas coconut (aromatic) had the lowest iodine value (11.32). Coconut (aromatic) had the highest saponification value (268) whereas ghee (home-made) had the lowest saponification value (211). Butter had the highest acid value (12) whereas palm (Dhaka) had the lowest acid value (0.17). Chromatographic analysis of fatty acids showed that soybean (USA) contained the % highest proportion of ω-6 fatty acids (54) whereas ghee of the open market contained the lowest (0.89). It was remarkable that coconut (aromatic), ghee (home-made), butter, dalda, mustard of the open market and mustard of ghani did not contain the ω-6 fatty acids. Palm from Chapai Nawabganj, palm from Dhaka, coconut (open market), coconut (aromatic), ghee(open market), ghee (home-made) butter and dalda did not contain any kind of ω-6 fatty acids. In the case of non-edible oils, percentage of iodine value was highest in tisi (137.35), whereas chamily had the lowest (1.35). A remarkable feature was that tisi contained such an enourmous proportion of 18:3 (ω-3) fatty acid (38.9) that could not be found normally in any kind of edible oil.