| Titles |
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English :
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Utilization of cheese industry fluid wastes to produce microbial emulsifying agents
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Arabic :
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الاستفادة من المخلفات السائلة لصناعة الجبن لانتاج مواد استحلاب ميكروبية
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| Abstract |
The main objective of this study was to test fifteen yeast strains for the production of extracellular emulsifiers when it grown in malt extract medium or in milk permeate for potential use food industry. The extracellular bioemulsifier production was very low in malt extract medium compared with milk permeate.
Candida utilis EMCCI02 and Torulaspora delbrueckii DSMZ 70607 recorded the superior results for bioemulsifier production in comparison with the other strains. When effect of nutritional requirements on bioemulsifier produced by C. utilis and T. delbrueckii from milk permeate ,it was found that the highest production and emulsifier activity level was obtained by C. utilis in milk permeate containing ammonium sulfate 800mg N/ L with 6.5 initial pH for 48h. incubation period.
On the other hand, the second strain T. delbrueckii in milk permeate contain ammonium citrate ( 400mg N / L ) with 6.5 initial pH for 48h. incubation period. The study examined the effect of different proportions of sodium chloride, pH value and some heat treatments on all free culture permeate of both Candida uti/is EMCCI02 and Torulaspora delbrueckii DSMZ 70607 stability and activity emulsifier. It was observed that C. utilis in the presence of 2 to 8 % ( w / v ) sodium chloride, there was no loss of emulsion stability compared to loss in the presence of salt concentration above 10 % , there was a loss of 12 %, the best pH values that gave the highest relative emulsifier activity was 4 - 6 and the relative emulsifier activity was decreased at 72 °C /15sec while relative emulsifier activity was increased at other heat treatments. On the other hand ,it was noticed that, the relative emulsifier activity in T. delbrueckii was stable at 8 - 12 % (w / v) sodium chloride on cell free culture permeate. It was found that when the level of pH value increased, the relative emulsifier activity increase is much higher at 8 pH value (180 % ), as well as , there was 10 % loss of relative emulsifier activity at 3 pH and the relative emulsifier activity was gradually declined when the heat treatment was increased
Therefore it was recommended that C. utilis could be used in dairy production, while T.delbrueckii strains is not recommended to be used in dairy production but i can be used successfully in other industries.
Separation of the bioemulsifier from milk permeate culture by C. utilis and examiniI1 of the properties of Candida emulsifier was carried out. The relative emulsifier stability was decreased after incubation as the temperature increase. Thus, the broad range of pH stability, thermo stability and salt tolerance suggested that, th, isolated bioemulsifier could be useful in the dairy industry.
The Candida emulsifier yield was 1.1g/L under given optimum conditio] Chemical analysis of this Candida emulsifier revealed that Candida emulsifier contained 0.57 % proteins, 0.93 % lipids and 98.5 % carbohydrates. About 25.4 % of the total carbohydrates was glucose The analytical tools used for investigation of the prepared compound, included IR spectra, IH NMR and GC/MS and these studies indicate the presence of some groups present in the tested compound such as OH, C=O and methylene groups which enabled to elucidate the structure of the Candida emulsifier.
Ice milk was chosen as an application model to be made using different ratios the microbial emulsifier produced by C. utilis. No obvious changes were recorded f gravity and weight / gallon of the mix but little increases were observed in the ovem and decreases in the melting rate of the resulting ice milk. Generally, the use of the microbial emulsifier produced by this yeast strain for making ice milk improved whipping qualities of the mixes and gave smoother body and texture.
Key words: milk permeate. - Yeast- Extracellular bioemulsifier - IR
spectra H NMR - GC/MS- Emulsion stability- Ice milk.
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| Publication year |
2006
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| Pages |
pp. 113
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| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
958
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| Organization Name |
Rabbit, Turkey and Water Fowl Research Department
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| Country |
Egypt
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| Author(s) from ARC |
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| Agris Categories |
Veterinary science and hygiene - General aspects
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AGROVOC
TERMS |
Yeasts.
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| Proposed Agrovoc |
milk permeate;Extracellular bioemulsifier;Emulsion stability;ice milk;
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| Publication Type |
PhD Thesis
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