Physicochemical, Microbiological, Sensory and Microstructure Properties of Camel Milk Cheese with Added Gum Arabic

Abstract

This study was conducted to evaluate the effect of addition of gum Arabic to the manufacture of cheese from camel milk and storage period on the physicochemical, microbiological properties, microstructure, syneresis and sensory properties of cheese. Camel milk cheese was formulated using calcium phosphate ( 0.3%), and gum Arabic at levels of 0.5%, 1%, 1.5% and 2%. Cow milk cheese was manufactured by the traditional method. Physiochemical, microbiological, syneresis and microstructure of cheese were determined. The study showed an increase in the moisture content by increasing storage time and decrease in moisture content by increasing the percentage of gum Arabic .The highest moisture content was 43.42% recorded for blank sample in the third month, while the lowest one was 28.99% which was recorded for camel milk cheese with 2% gum Arabic added in zero time. The lowest protein content was in the sample of camel milk cheese without gum Arabic in the third month which was 18.96 % .The highest protein content was in the sample of camel milk with 2% gum Arabic at the first month which was 25.25%, The highest percentage of fat content was in the sample of camel milk cheese with 2% gum Arabic at zero time which was 35.40% and the lowest one was in the blank sample in the third month, 29.52%. The highest percentage of ash content in camel milk cheese with 2% gum Arabic at zero time which was 10.79% and the lowest percentage in the blank sample in the third month which was7.98%. Total soluble solid decreased by increasing the storage period and increased by increasing the amount of gum Arabic. Lactose appeared only in a blank sample and a sample of cow milk. pH-value decreased by increasing the storage period and by increasing the amount of gum Arabic. Titratable acidity of cheese increased by increasing the storage period and amount of gum Arabic. The total bacterial count (log10cfu/ml) of raw milk for cow and camel was 3.64 and 5.63 respectively, while coliforms (MPN/ml) were 21.67 and 19.4 respectively, Staphylococcus (log10cfu/ml) was 2.13 and 3.4 respectively, and E. coli bacteria were found in the camel milk sample 5.5, whereas Brucella, Salmonella, Shigella and yeasts and moulds were not detected in all samples of raw milk. The average total viable bacterial count (log10cfu/g) was 3.5, the average number of Staphylococcus aureus (log10cfu/g) in cheese was 3.1 . Yeasts and moulds, E. coli, Salmonella, Shigella and Brucella were not detected in cheese samples. The colour of camel milk cheese containing 1% and 2% gum Arabic was less acceptable, camel milk cheese without gum Arabic obtained moderate acceptance and cow milk cheese obtained the highest acceptance. Taste of sample containing 1% gum Arabic found the acceptance of the panelists while the sample containing 2% gum Arabic was not accepted by the panelists. Flavour of cheese contained 0.5% gum Arabic was moderately bland while that of sample containing 1% gum Arabic was moderately intense. Texture of the camel milk cheese with 1% gum Arabic was soft, camel milk cheese without gum Arabic was to some extent hard. The general acceptance of camel milk cheese containing 1% gum Arabic was more acceptable than the sample containing 2% gum Arabic and cow milk cheese. Syneresis of cheese increased by increasing the storage period and amount of gum Arabic, the highest ratio of whey was in camel milk cheese without gum Arabic sample which was 56% when the lowest one was in the sample with 1% gum Arabic 49.33%. The use of gum Arabic in the manufacture of camel milk cheese at1% gum Arabic led to an improvement in some sensory and physicochemical properties of cheese. Making cheese from camel milk with added gum Arabic helps to get rid of some pathogenic microbes such as E. coli. Porosity of camel milk cheese was decreased by increasing the ratio of gum Arabic.