Characterization of Penicillium roqueforti isolates from Turkish blue cheeses: Technological traits, secondary metabolites, and performance in model cheeses

Abstract

Blue cheeses owe their distinctive texture, flavor, and aroma to Penicillium roqueforti. Understanding the technological traits and secondary metabolite production of this species is essential for cheese quality and safety. Here, 20 P. roqueforti isolates from traditional Turkish blue cheeses, including Tulum and Civil, were evaluated for growth at different temperatures, salt tolerance, proteolytic and lipolytic activities, and production of mycophenolic acid (MPA) and roquefortine C (ROQC). Marked strain-level variation was observed. Hierarchical clustering and principal component analysis grouped the isolates into three clusters. Civil cheese isolates showed improved growth under temperature and salt stress and produced lower ROQC than Tulum isolates, suggesting adaptation to distinct cheese environments. Selected isolates were tested in model Tulum cheeses, where all successfully colonized and formed blue veins. Secondary metabolite levels in cheese were low. These results highlight the diversity of Turkish P. roqueforti isolates and support the development of cheese-specific starter cultures.