ash using standard methods of the Association of Official Analytical Chemists [14]. The carbohydrate content was obtained by difference. Potassium and sodium were determined using the modified method of Bonire et al. [15] by digesting the ash of the pulp with perchloric acid and nitric acid and taking the readings on Jenway digital flame photometer/spectronic20. Phosphorus was determined by vanado-molybdate colorimetric method. Calcium, magnesium, iron, zinc and manganese were determined spectophotometrically by using Buck 200 Atomic Absorption Spectrophotometer (Buck scientific, Norwalk) [16]; and their absorption compared with absorption of standards of these minerals. The ascorbic acid content of the leaf was determined by titration with 2, 6-dichlorophenolindophenol solution, while riboflavin was extracted using 5ml of 5M HCl and 5ml of dichloroethene and measurement made with fluorometer. Standard solution of riboflavin was prepared and readings taken; then the leaf riboflavin obtained through calculation. The leaf’s beta-carotene was extracted with chloroform and determined through ultraviolet absorption measurement at 328nm. Calibration curve of standard β-carotene solutions absorption was made and the leaf β-carotene concentration estimated as microgram (μg) of β-carotene/100g sample. Oxalate was determined by extraction with water for about three hours. The absorbance of the leaf extract was read on spectrophotometer (Spectronic 20) at 420nm. Standard solutions of oxalic acid were prepared and their absorption was also read at 420nm to obtain a standard curve from which the amount of oxalate was estimated. Phytate was determined by titration method using ferric chloride solution [17]; while tannin content was determined by extracting the leaf with a mixture of acetone and acetic acid for five hours. Their absorbance was measured and compared with that of standard solutions of tannic acid at 500nm on spectronic 20 [18]. Saponin of the extract was determined by measuring its absorbance and comparing with that of standard solutions at 380nm [19]. Nitrates were determined by using EDTA solution, and nitrites with sulphanilamide/N-1naphthylethelene diamine dihydrochloride solution, and absorbance measured at 538nm [20]. The results of the analyses were subjected to Chi square test and level of significance taken at 95% confidence level.
ash using standard methods of the Association of Official Analytical Chemists [14]. The carbohydrate content was obtained by difference. Potassium and sodium were determined using the modified method of Bonire et al. [15] by digesting the ash of the pulp with perchloric acid and nitric acid and taking the readings on Jenway digital flame photometer/spectronic20. Phosphorus was determined by vanado-molybdate colorimetric method. Calcium, magnesium, iron, zinc and manganese were determined spectophotometrically by using Buck 200 Atomic Absorption Spectrophotometer (Buck scientific, Norwalk) [16]; and their absorption compared with absorption of standards of these minerals. The ascorbic acid content of the leaf was determined by titration with 2, 6-dichlorophenolindophenol solution, while riboflavin was extracted using 5ml of 5M HCl and 5ml of dichloroethene and measurement made with fluorometer. Standard solution of riboflavin was prepared and readings taken; then the leaf riboflavin obtained through calculation. The leaf’s beta-carotene was extracted with chloroform and determined through ultraviolet absorption measurement at 328nm. Calibration curve of standard β-carotene solutions absorption was made and the leaf β-carotene concentration estimated as microgram (μg) of β-carotene/100g sample. Oxalate was determined by extraction with water for about three hours. The absorbance of the leaf extract was read on spectrophotometer (Spectronic 20) at 420nm. Standard solutions of oxalic acid were prepared and their absorption was also read at 420nm to obtain a standard curve from which the amount of oxalate was estimated. Phytate was determined by titration method using ferric chloride solution [17]; while tannin content was determined by extracting the leaf with a mixture of acetone and acetic acid for five hours. Their absorbance was measured and compared with that of standard solutions of tannic acid at 500nm on spectronic 20 [18]. Saponin of the extract was determined by measuring its absorbance and comparing with that of standard solutions at 380nm [19]. Nitrates were determined by using EDTA solution, and nitrites with sulphanilamide/N-1naphthylethelene diamine dihydrochloride solution, and absorbance measured at 538nm [20]. The results of the analyses were subjected to Chi square test and level of significance taken at 95% confidence level.
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