Characterization and Functional Properties of Azadirachta indica GUM From Sudan

Abstract

Forty five samples of the gum from Azdirachta indica gum were collected from three locations (15 samples from each location) Khartoum, White Nile and Northern Kordofan states. from Sudan, during seasons 2014-2016; Three composite samples were prepared form the fifteen samples of each location by mixing. Chemical and Physicochemical properties were studies amino acids profile, molecular weight and molecular weight distribution, rheological behavior and emulsification properties of Azadirachta indica gum. The results show the ranges for moisture content 11.2 - 12.2%, Ash content 3.0 – 3.30%, pH 4.2 – 4.8, Specific optical rotation -65.5 – -67, color Gardena (0.1 - 0.9), nitrogen content 4.8– 5.2%, hence protein% 30.2– 31.3%, tannin .04 –.010%, acid equivalent weight 1543 – 1708, total uronic acid% 11.3 – 12.5% and intrinsic viscosity 24 – 36 cm3g-1 .The calorific value was 4.3 kJ/mole. Acid hydrolysis revealed a sugar content Arabinose 14–22%, Galactose 17– 24%, Xylose 3 –4% and Rhammnose 2 –4%. The Cationic composition showed that Mg 57.1–38.9, Na 24.5–13.9, Ca12.6–9.6, K11.9–6.2, Cu 0.11–0.16, Zn 0.06–0.08, and P0.0.2–0.04mg/g. The amino acid results shows the presence of seventeen amino acids namely, Asparagine, Threnine, Serine, Glutamine, Proline, Glysine, Cysteine, Alanine, Valine, Methionine, Isoleucine, Leucine, Tyrosine, Phenylalanine, Histidine, Lysine, and Araginine. Number average molecular weight (Mn) was range in the 6.4×105 –12 ×105 g/mol . The molecular weight determined by gel permeation chromatography (GPC-MALLS) for the three location composite (Khartoum, White Nile and Northern Kordofan states) respectively. The samples have Molar masses of 4.8x105 , 4.00 x105 g/mole, V and 3.6 x105 g/mole. With a radius of gyration ( Rg) in the range of (25.6 – 36.6 – 66 ), respectively. Azadirachta indica gum samples (composite ) collected from Khartoum location show an Arabinogalactan protein (AGP) with total molecular weight 3.8x105 mass% 1.34, and Rg 63.7 . The second and third fractions correspond to an (Arabinogalactan AG + Glycoprotein GP) have molecular weight of 3.292x105 g/mole and mass recovery of 98.13. GPC-MALLS for neem gum samples collected from White Nile shows an AGP with a molecular weight of 4.00x105, mass% 1.77, and Rg 43.2 The second and third fractions are (AG +GP) have a molecular weight of 3.193x105 g/mole , mass% 98.66, GPC-MALLS for Azadirachta indica gum samples collected from Northern Kordofan location shows an AGP with a molecular weight of 3.8x105, mass%.87, and Rg 52.2 The second and third fractions are (AG +GP) have a molecular weight of 3.292x105 g/mole , mass% 99.13. The rheological behavior of Azadirachta indica gum show a Newtonian behavior All emulsions show Low droplets size, exhibit a typical bimodal droplet size distribution with a pronounced shoulder reflecting best formity and stable emulsions. The gum emulsion shows first grade emulsification properties. Azadirachta indica gum shows insignificant differences (were observed) samples collected from the three different locations from Sudan