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Glucose was completely removed from egg white in g h by using Sfreplococcus lacfis and 0.2% yeast extract a t pH 6.0 and 30 "C. A distinct objectionable odour was developed accompanied by a change in the appearance of egg white. Using Aerobacfer aerogenes at pH 7.0 and 37 "C, glucose depletion was completed after 3 to 4 h depending on the initial number of bacteria used. The undesirable changes in odour and appearance of egg white were not observed. Saccharomyces cercvtsiae succeeded, in presence of 0.2% yeast extract, in depleting sugar in egg white in g h. The optimum pH for the reaction was in the range of 6.0 to 7.5 at 32 'C. Glucose oxidase powder of fungal origin was also used for glucose depletion. Glucose was completely removed after 8 h by adding 3.8 glucose oxidase units/roo ml egg white at pH 7.3 and 14.5 "C. I .g and 0.95 glucose oxidase units per IOO ml egg white were not enough for complete glucose removal. No objectionable odour or undesirable changes in egg white were observed.Dehydration of liquid egg white without removal of glucose results in poor storage stability of dried product [I]. The aldehydic group of glucqse reacts with the amino groups of protein resulting in browning and insolubility of the dried product (MAILLARD reaction). It was recommended that glucose must be removed prior to drying to retard this reaction [2. 31.Formerly sugar was depleted from egg white by permitting a spontaneous fermentation to take place. STUART et al. [4] found that the bacteria present in this case were usually of the genera Aerobacfei and Eschcrzchia. The experimental results of AYRES [5] indicated that glucose could be removed from egg albumen by using Saccharomyces cerevisiae, Streptococcus lacfis and Aerobacfer aerogenes.The experiments of CARLIN et al. [6] on the effect of removal of glucose by glucose oxidase revealed that treated dried albumen rehydrated readily and had no off flavour or odour.HAMED et al. [7], trying to prepare dried egg white as a new ihdustry in Egypt, used a crude enzyme complex prepared from Penicillium notatum for depleting glucose from chicken egg white before drying. I t was found during their work that natural fermentation of egg white was unsuccessful in removing glucose, which contradicts the results of STEWART et al. [8].The authors explained the difference to be due to the difference in both chemical and bacteriological composition of eggs in different countries. So it was the purpose of the present study to try several methods for depleting glucose in Egyptian egg white before dehydration. This was done in an attempt to establish the best method for glucose depletion that would give dried egg white of high quality. However the evaluation of the final dried products will come next.Glucose removal from egg white was done using both active dry yeast (Saccharomyces cerevisiae) and bacteria (Sfreptococcus lacfis and Aerobacfer aevogenes). Besides, another experiment, similar to that of HAMED et al. [7], was carried out in which the source of enzyme was changed, to find out...

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Egg white was dehydrated (pan drying, spray drying) without and with glucose removal (using bacteria, yeast and enzyme). Although, moisture, protein and ether extract percentage in spray dried samples were, in general, in the same range as the imported Swiss made spray dried sample (as standard), yet the least moisture percentage was found in samples in which sugar was removed by yeast. The standard sample had the best solubility (99.79%). followed by the spray dried sample desugarized by yeast (99.677;). Samples in which Stvepfococcus lacfis was used gave the highest percentage of insoluble matter (4.z4X). Pan dried and spray dried samples were similar in solubility.The total microbial counts were found to decrease in egg white after drying (max. 4.9 x 10 org.in prepared samples, zero in the standard). Salmonella was absent in all dried samples. There are variations in the type of protein fractions of liq'uid egg white when the enzyme treatment or controlled bacterial fermentation were used. When yeast fermentation was used a decrease in some protein fractions was noticed in comparison with the nondesugarized sample. The dehydrated egg ,white proteins indicate that there was no difference between the different techniques applied for glucose removal, between drying methods and between prepared samples and imported one; 5 fractions were obtained in each sample.-411 over the world, the demand for dehydrated egg white began to increase for many industries such as an adhesive for cork in bottles capsules in carbonated beverage plants, for coating of roasted coffee and for use in cake mixes.Dehydration of egg white is carried out mainly by two ways, pan drying or drum drying and spray drying processes. The drying process should permit the retention of certain valuable properties of the fresh egg white such as solubility of the protein, aerating capacity, binding power and palatability.Dehydration 758DARWISH/SHEHAB/SADEK countries. They succeeded in depleting glucose in Egyptian egg white by using a crude enzyme complex which contained glucose oxidase and catalase and was prepared from penicillium notaturn. DARWISH et al.[6] studied the different methods that could be applied for depleting glucose in Egyptian egg white before dehydration. The present study was done to find out the best method that could be applied for preparing dried egg white in Egypt as a new industry. Egg .white was dehydrated with and without glucose removal.Glucose removal was carried out using bacteria, yeast and enzyme. Both pan drying and spray drying methods were used.Evaluation of the final dried products was done by determining both chemical and microbial composition of prepared dried products in comparison with an imported dried sample.Electrophoretic analysis of protein was carried out on liquid egg white before and after glucose removal and after dehydration. Materials and methodsChicken eggs were obtained from the poultry farm of the Animal Husbandry Dept. Ministry of Agriculture, Cairo, Egypt.The eggs were first washed, then examined b...

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Egg white was spray dried, using Egyptian fresh eggs, with and without glucose removal. Glucose depletion in egg white was carried out using bacteria, yeast and enzyme. Foam capacity and stability of liquid egg white was found to decrease after glucose was removed by the different methods used. Foam capacity was also decreased by dehydration, except for egg white in which enzyme was used for glucose removal. Foam was more stable in samples desugared by yeast and least stable in enzyme treated egg white. Both pan drying and spray drying methods had the same effect on foam capacity and stability of egg white. The pH value of liquid egg white was found to decrease by removing glucose and to increase by dehydration. The specific volume data and organoleptic evaluation of angel food cakes in which dehydrated egg white, imported dried egg white and fresh egg white were used, showed that the best method to prepare dehydrated egg white is by using enzymatic treatment for glucose removal before dehydration.Dehydration of egg white is carried out mainly by two ways, pan drying and spray drying processes. The drying process should permit the retention of certain valuable properties of the fresh egg white such as solubility, foaming capacity and palatability. I t was recommended that glucose must be removed prior to drying tq avoid MAILLARD reaction which results in browning and poor storage stability of products [ I , 23. Natural fermentation of Egyptian egg white was unsuccessful in removing glucose [3]. DARWISH et al. [4] studied the different methods that could be applied for preparing dried egg white as a new industry in Egypt. Egg white was dehydrated, with and without glucose removal. Glucose was removed by different methods including the use of bacteria, yeast and enzyme.The present study is concerned with the technological evaluation of dried egg white, prepared by the different techniques mentioned before. I t includes : -Effect of drying on the foaming capacity and foam stability of egg white.-As the hydrogen ion concentration is known to be an important factor in determining the foaming capacity of egg white, it was decided to study the effect of removing glucose and dehydration on the pH value of egg white.-Effect of the drying process on the palatability of egg white. Materials and methodsChicken eggs were obtained from the poultry farm of the Animal Husbandry Dept., Ministry of Agriculture. Cairo, Egypt. They were washed, then examined by candling [ 5 ] . Egg white was separated, blended and strained. The imported egg white powder that was used for comparison was spray dried, Swiss made.-Bacterial fermentation using Stv. Iactis in presence of 0 . 2 % yeast extract a t pH (3.0 and 30 OC [ 6 ] .-Bacterial fernientation using Aer. aerogenes a t pH 7.0 and 37 'C [ 6 ] .The methods used for glucose depletion in liquid egg white were:

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