title: Validation of a predictive model for the growth of chalk yeasts on bread.
abstract: The present study focused on the effects of temperature, T, and water activity, aw, on the growth of Hyphopichia burtonii, Pichia anomala, and Saccharomycopsis fibuligera on Sabouraud Agar Medium. Cardinal values were estimated by means of cardinal models with inflection. All the yeasts were xerophilic, and they exhibited growth at 0.85 aw. The combined effects of T, aw, and pH on the growth of these species were described by the gamma-concept and validated on bread in the range of 15-25 °C, 0.91-0.97 aw, and pH 4.6-6.8. The optimum growth rates on bread were 2.88, 0.259, and 1.06 mm/day for H. burtonii, P. anomala, and S. fibuligera, respectively. The optimal growth rate of S. fibuligera on bread was about 2 fold that obtained on Sabouraud. Due to reproduction by budding, P. anomala exhibited low growth on Sabouraud and bread. However, this species is of major concern in the baker's industry because of the production of ethyl acetate in bread.
authors.affiliation: UMR PAM A 02.102, Laboratoire des Procédés Microbiologiques et Biotechnologiques, Université de Bourgogne, Agro-Sup Dijon, 1 Esplanade Erasme, 21000 Dijon, France.
authors.forename: Anaïs
authors.initials: A
authors.lastname: Burgain
authors.affiliation: UMR PAM A 02.102, Laboratoire des Procédés Microbiologiques et Biotechnologiques, Université de Bourgogne, Agro-Sup Dijon, 1 Esplanade Erasme, 21000 Dijon, France.
authors.forename: Maurice
authors.initials: M
authors.lastname: Bensoussan
authors.affiliation: UMR PAM A 02.102, Laboratoire des Procédés Microbiologiques et Biotechnologiques, Université de Bourgogne, Agro-Sup Dijon, 1 Esplanade Erasme, 21000 Dijon, France; Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France. Electronic address: philippe.dantigny@univ-brest.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Dantigny
mesh_terms: D001939:Bread / Q000382:microbiology*; D003470:Culture Media; D005506:Food Contamination; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D008962:Models, Theoretical; D004718:Saccharomycetales / Q000254:growth & development*; D013696:Temperature; D014867:Water; D015003:Yeasts / Q000254:growth & development*
chemical_list: D003470:Culture Media; D014867:Water
keywords: Bread; Hyphopichia burtonii; Model; Pichia anomala; Predictive mycology; Saccharomycopsis fibuligera