Study of chemical composition and quality properties of gum extracted from jujube fruits (Zizyphus sp) and its potential use in food processing

Afraa Mamdoh Masri
General Commission for Scientific Agricultural Research ,Department of Food Technology.
Faculty of Agriculture, Tishreen University.
2017

Abstract

Gum is one of complex carbohydrates that formed in the different parts of plants , it characterized by low cost of production as well as being one of the additives that are currently taking a lot of attention due to the properties collection which is characterized , and it was the purpose of this research to study the chemical composition and some physicochemical and functional properties of the mucilage extracted from the jujube  fruit. And that for the two types normal jujube ( Z. jujube ) and wild jujube ( Z. lotus) , and test the efficiency of products and the statement of its effect on the sensory properties of the studied product. And compared to these properties with one of  imported commercial gums, it has been used this gum Arabic for comparison.
This study was carried out in the framework of joint cooperation between Tishreen university and the General Commission for Sciences ، Faculty of Agriculture Research in the period ( 2015-2017).
The yield of mucilage output of both types were very high. differences between them that, the yield of the Z.lotus increased by (25.23%) estimated on the basis of the dry weight of the fruits, and it fell in Z. jujube to (5.79 %) it seen through the chemical composition of the studied gums thoughtful appreciation . The high content of carbohydrates it was (85.85%) for gum Arabic, used for comparison and (87.57%) for Z.lotus and (89.83 % )for Z .jujube. While the proportion of protein and ash were low, the fat content was non- existent for three types of studied gums.
In terms of physicochemical properties of the tasted gums the/ ph./ value   was  neutral for both of Z .jujube and Z.lotus    ( 6.32) and less than for the  gum Arabic ( 5.59) , specific gravity Bulk density/Tap density refractive index/  Hausner index / swelling index/ and Compressibility index/ of Z.lotus mucilage were higher than Z .jujube mucilage, and were respectively , for Z. lotus mucilage ( 5.59- 1.15- 1.336/ 9/cm , 0.49 , 0.42 – 1.0055 , g /cm ) respectively.

Which are similar to the properties of gum Arabic , while they were in Z .jujube mucilage ( 1.0047- 0.40 g/ cm3 – 0.43 g /cm3 – 1.335- 1.04- 3.947- 4.64% ) respectively.
Differences between the both of Z. jujube and Z. lotus were too high , in items of functional properties the Water holding capacity to the lotus mucilage reached to (34.01 g water / g dry mucilage) and it did not exceed (14.6 g water / g dry mucilage) for Z .jujube mucilage .
The Oil holding capacity and relative viscosity of Z. lotus mucilage also increased more than gum Arabic and Z. jujube mucilage.
For the sensory evaluation won creamy ice cream sample tested by adding Z. lotus mucilage . The highest total, and the sensual properties like shape, textures, color , flavor and resistance to assimilation were the best compared to the addition of the samples tested Z .jujube mucilage and gum Arabic.

These results indicate that the mucilage extracted from both mentioned types of jujube can be used as stabilizer in   the field of food industry.and use it as a substitutes for imported commercial gums.

Key word: gum, jujube fruits, Refractive index , Water holding capacity.