Lipid content and cryotolerance of bakers' yeast in frozen doughs

• Published in: Applied and Environmental Microbiology Vol. 57; no. 2; pp. 463 - 468
• Main Authors: Gelinas, P. (Agriculture Canada, Saint-Hyacinthe, Quebec, Canada), Fiset, G, Willemot, C, Goulet, J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.02.1991
• Subjects: ACIDE GRAS; ACIDOS GRASOS; ALIMENT SURGELE; ALIMENTOS CONGELADOS; AZOTE; Biological and medical sciences; BIOMASA; BIOMASSE; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CONGELACION; CONGELATION; CONTENIDO PROTEICO; ESTEROLES; EXPERIMENTATION EN LABORATOIRE; EXPERIMENTOS EN LABORATORIO; FERMENTACION; FERMENTATION; Food Microbiology; FOSFATOS; FOSFORO; Fundamental and applied biological sciences. Psychology; LIPIDE; LIPIDOS; MASA DE PANADERIA; METHODE; METODOS; Microbiology; NITROGENO; PATE DE CUISSON; PHOSPHATE; PHOSPHORE; PRODUCCION ALIMENTARIA; PRODUCTION ALIMENTAIRE; PROTEINA BRUTA; PROTEINE BRUTE; SACCHAROMYCES CEREVISIAE; STEROL; TENEUR EN PROTEINES; Fungi; Temperature; Yeast; Cryopreservation; Tolerance; Ascomycetes; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.57.2.463-468.1991

The relationship between lipid content and tolerance to freezing at -50 degrees C was studied in Saccharomyces cerevisiae grown under batch or fed-batch mode and various aeration and temperature conditions. A higher free-sterol-to-phospholipid ratio as well as higher free sterol and phospholipid contents correlated with the superior cryoresistance in dough or in water of the fed-batch-grown compared with the batch-grown cells. For both growth modes, the presence of excess dissolved oxygen in the culture medium greatly improved yeast cryoresistance and trehalose content (P. Gelinas, G. Fiset, A. LeDuy, and J. Goulet, Appl. Environ. Microbiol. 26:2453-2459, 1989) without significantly changing the lipid profile. Under the batch or fed-batch modes, no correlation was found between the cryotolerance of bakers' yeast and the total cellular lipid content, the total sterol content, the phospholipid unsaturation index, the phosphate or crude protein content, or the yeast cell morphology (volume and roundness)