Extraction and Concentration of Glutathione from Yeast

Abstract

Glutathione is a tripeptide present in most mammalian tissue. It has a great variety of significant physiological functions, such as regulating cell growth and division; helping DNA synthesis and repair. Glutathione can be used in food additive and cosmetic industries at present. This study aimed to extract glutathione from yeast using hot-water and to concentrate glutathione by membrane separation processes, including ultrafiltration and nanofiltration. Glutathione recovery efficiency by hot-water extraction was 73.8%. Supernatant obtained by hot water extraction was first passed through a ultrafiltration membrane to remove macromolecules, and then glutathione in this permeate was concentrated using a nanofiltration membrane. Glutathione recovery efficiency in nanofiltration step was 99.7%. In addition, the performance of the membranes used in this study was tested, including the permeation flux of supernatant and aqueous glutathione solution by ultrafiltration and nanofiltration and the rejection of glutathione by these two processes. This study also investigated the effect of hot water extraction time and temperature on the glutathione yield, and exposure to light on the stability of glutathione extracted was also studied.