Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Food Science and Technology

This study aimed to extract the high methoxyl pectin from the orange peels of shamouti variety by using two different methods of extraction. The first method was applied by using sodium hexametaphosphate (SHMP) at pH 4.5 at 95{u00B0}C for 60 min. Meanwhile, in the second method nitric acid (NA) was used at pH 1.6 at 80 - 90{u00B0}C for 60 min. The Shamouti orange fruit was chosen because it contains thick albedo layer which constituted about 35.7% from fruit weight. The gross chemical composition of orange peels of Shamouti variety indicated that total sugars, total ash, crude protein, ether extract were 2.75, 2.11, 3.52 and 1.50 % (on dry wt. basis), respectively. Meanwhile, moisture and total indigestible carbohydrates constituted 9.86% and 61.22%, respectively. Moreover, the content of total pectic substances reached 28.90%, on dry wt. basis. Results showed that the superiority was belonged to NA pectin of the characteristics concerning pectin yield, pectin recovery, equivalent weight, methoxyl content, degree of esterification, acetyl value and molecular weight which were 27.95, 96.70, 618.51, 7.60%, 59.70%, 0.16% and 940.10 kDa, respectively compared with SHMP pectin

Issued also as CD