Extraction of The Major Egg White Proteins- Optimization and Scale-Up

  • Author / Creator
    Kharbanda, Manjot Singh Kuldip Singh
  • Eggs are an excellent source of nutrients. Egg whites are used in food, cosmetic, and biotechnology industries for a plethora of physiological functions that they demonstrate due to their proteins. Although these proteins look promising, they can be utilised only after they have been isolated/extracted from the egg white. The objectives of this study were to develop a procedure for the extraction of the major egg white proteins, lysozyme (LSZ), ovomucin (OVM), ovotransferrin (OVT), and ovalbumin (OVA), and to simplify the developed method in order to execute a step wise scale-up from a lab scale (100 g egg white) to a pilot scale (20 kg egg white). The specific focus of this study was to improve the existing protocols in order to reduce the experimental setup requirement and thus reduce the cost of extraction. This was achieved by optimizing the extraction conditions for LSZ (cation exchange resin based separation), applying the traditional siphon filtration for the separation of resin particle, OVM, and OVT precipitates, and elimination of any heat treatments for OVA purification.

    In case of LSZ, the extraction was achieved in a shorter time (180 min), with lesser resin dosage (2 g/100 g egg white) and without any pH buffers. For OVM, a modification of the 2-step method was performed and for the scale up study, siphon filtration was used. OVT was separated by the ammonium sulfate and citric acid salting out method and OVA was obtained as a supernatant at the end of the process and needed no further purification. The siphon filter used was designed indigenously in the lab using food grade transparent vinyl tubing, stainless steel mesh (100 mesh size for resin separation and 400 mesh size for precipitate separation), and waterproof silicone sealing tape to hold the filter in place with the tube opening and avoid any leakages. The proteins extracted in this study had comparable purities and yields than the previously reported methods. For example, from 100 g egg white, an average yield of 58% for LSZ, 83% for OVM, 75% for OVT, and 99% for OVA were achieved, and the average purities were 92%, 85%, 69%, and 94%, respectively. The process developed in this study is easy to adapt and has a potential for scale-up to an industrial scale as was proven from our stepwise scale up batches of 1kg and 20kg which achieved similar average yields and purities (p>0.05).

  • Subjects / Keywords
  • Graduation date
    Fall 2022
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.