- 1Université
de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et Ecologie
Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané,
France.
- 2STLO, UMR1253, INRA, Agrocampus Ouest, 65 rue de Saint Brieuc, 35000 Rennes, France.
- 3Université
de Brest, EA 3882 Laboratoire Universitaire de Biodiversité et Ecologie
Microbienne, IBSAM ESIAB, Technopôle Brest-Iroise, 29280 Plouzané,
France. Electronic address: monika.coton@univ-brest.fr.
Abstract
Penicillium roqueforti
is used as a ripening culture for blue cheeses and largely contributes
to their organoleptic quality and typical characteristics. Different
types of blue cheeses are manufactured and consumed worldwide and have
distinct aspects, textures, flavors and colors. These features are well
accepted to be due to the different manufacturing methods but also to
the specific P. roqueforti strains used. Indeed, inoculated P. roqueforti
strains, via their proteolytic and lipolytic activities, have an effect
on both blue cheese texture and flavor. In particular, P. roqueforti
produces a wide range of flavor compounds and variations in their
proportions influence the flavor profiles of this type of cheese.
Moreover, P. roqueforti
is also characterized by substantial morphological and genetic
diversity thus raising the question about the functional diversity of
this species. In this context, 55 representative strains were screened
for key metabolic properties including proteolytic activity (by
determining free NH2 amino groups) and secondary metabolite
production (aroma compounds using HS-Trap GC-MS and mycotoxins via
LC-MS/Q-TOF). Mini model cheeses were used for aroma production and
proteolysis analyses, whereas Yeast Extract Sucrose (YES) agar medium
was used for mycotoxin production. Overall, this study highlighted high
functional diversity among isolates. Noteworthy, when only P. roqueforti
strains isolated from Protected Designation of Origin (PDO) or
Protected Geographical Indication (PGI) blue cheeses were considered, a
clear relationship between genetic diversity, population structure and
the assessed functional traits was shown.
Copyright © 2016 Elsevier B.V. All rights reserved.
KEYWORDS:
Cheese; Mycotoxins; Penicillium roqueforti; Proteolysis; Secondary metabolites; Volatilome
