title: [Water activity and food stability. I. Effects on viability of Saccharomyces cerevisiae cells (author's transl)].
abstract: Biological activity of microorganism is related to water activity (aw). In this paper the effect of glicerol as humectant on Saccharomyces cerevisiae viability was considered. The irreversible loss of viability was observed only for values inferior than 0,75. The K+ presence promoted an increasing of cell viability and growth. We have evaluated the changes of the most important components of cell poll; the increasing of glicerol amount of the system induced a drastic fall of aminoacids, purines and K ions content, but it increased the Na ions content. The exposure of cells to increasing glicerol concentrations, caused an aminoacids and purines excretion related to contact time; after a few hours this material was readsorbed by cells.
mesh_terms: D003890:Desiccation; D005516:Food Microbiology; D005519:Food Preservation; D005612:Freeze Drying; D005990:Glycerol / Q000494:pharmacology; D012441:Saccharomyces cerevisiae; D014867:Water
chemical_list: D014867:Water; D005990:Glycerol
vernacular_title: Stabilità degli alimenti in funzione dell'attività dell'acqua. I. Disattivazione delle cellule di Saccharomyces cerevisiae