Pectin yield was determined as weight of dry pectin against the weight of initial residues multiplied by 100%.
Y=100(P/Bi)
Where Y is the extracted pectin yield (%), P is the amount of extracted pectin in grams and Bi is the initial amount of sweet potato residues used to extract pectin. Equivalent weight and Degree of methoxylation
The equivalent weight was determined according to the method by Barretina et al., (Barretina et al. 2012). 0.25g pectin was wetted with 5ml ethanol and topped to 100mL mark in a with deionized water, thereafter six drops of phenolphthalein was added and the content stirred on a plate stirrer with magnet to fully solubilize pectin.. The solution was titrated against 0.1M NaOH solution till PH 7.5 was attained (when the colour just started to turn pink). The following equation was applied to establish equivalent weight:
Equivalent weight (EW)=(weight of pectin sample x 1000)/(volume of alakali (〖cm〗^3 )x Normality of Alkali)
The …show more content…
Dilution range was made between 2mg/ml-300mg/ml of pectin in deionized water. FeSO4 standard consisting of 0.2, 0.4, 0.6, 0.8 and 1mM in deionized water was used to plot a standard curve, the activity of pectin was determined relative to 1mM of the standard. The stock solutions include 300mM acetate buffer, pH 3.6, 10mM TPTZ (2, 4, 6-tripyridyl-S-triazine) solution in 40 mM HCl and 20 mM Fecl3.6H2O. The working solution was prepared fresh by mixing 25 ml acetate buffer, 2.5 ml TPTZ and 2.5 ml FeCl3.6H2O, and its temperature raised to 37ºC before use. 150µL of pectin solution was mixed with 2850µL of FRAP solution for 30 min in the dark condition. The absorbance of the reaction mixture (Ferrous-tripyridyltriazine complex) was read at 593 nm. The standard curve displayed a linear trend between 200 and 1000 µM Feso4. Results was expressed relative to µM (Fe
Y=100(P/Bi)
Where Y is the extracted pectin yield (%), P is the amount of extracted pectin in grams and Bi is the initial amount of sweet potato residues used to extract pectin. Equivalent weight and Degree of methoxylation
The equivalent weight was determined according to the method by Barretina et al., (Barretina et al. 2012). 0.25g pectin was wetted with 5ml ethanol and topped to 100mL mark in a with deionized water, thereafter six drops of phenolphthalein was added and the content stirred on a plate stirrer with magnet to fully solubilize pectin.. The solution was titrated against 0.1M NaOH solution till PH 7.5 was attained (when the colour just started to turn pink). The following equation was applied to establish equivalent weight:
Equivalent weight (EW)=(weight of pectin sample x 1000)/(volume of alakali (〖cm〗^3 )x Normality of Alkali)
The …show more content…
Dilution range was made between 2mg/ml-300mg/ml of pectin in deionized water. FeSO4 standard consisting of 0.2, 0.4, 0.6, 0.8 and 1mM in deionized water was used to plot a standard curve, the activity of pectin was determined relative to 1mM of the standard. The stock solutions include 300mM acetate buffer, pH 3.6, 10mM TPTZ (2, 4, 6-tripyridyl-S-triazine) solution in 40 mM HCl and 20 mM Fecl3.6H2O. The working solution was prepared fresh by mixing 25 ml acetate buffer, 2.5 ml TPTZ and 2.5 ml FeCl3.6H2O, and its temperature raised to 37ºC before use. 150µL of pectin solution was mixed with 2850µL of FRAP solution for 30 min in the dark condition. The absorbance of the reaction mixture (Ferrous-tripyridyltriazine complex) was read at 593 nm. The standard curve displayed a linear trend between 200 and 1000 µM Feso4. Results was expressed relative to µM (Fe