Bioactive components in mold-ripened Civil cheese: Profiling peptides, gamma-aminobutyric acid (GABA), and biogenic amines

Civil cheese, produced in Türkiye, particularly in the Eastern Anatolia Region, is a distinctive cheese variety characterized by spontaneous mold growth during ripening. This spontaneous mold development, together with its complex microbial ecosystem, makes Civil cheese a remarkable model for investigating the bioactive compounds formed throughout the ripening process. In this study, twenty-five moldy Civil cheese samples were comprehensively evaluated for their bioactive component profiles (bioactive peptides, γ-aminobutyric acid-GABA, and biogenic amines), as well as their physicochemical and microbiological characteristics. The cheeses exhibited a diverse microbiota, with high counts of lactic acid bacteria, yeasts, and molds. The chemical composition showed moderate variability, particularly in pH (4.57–7.25) and titratable acidity (0.23–0.83 %). The ripening index ranged from 6.08 to 18.91 %, reflecting varying levels of proteolysis. Electrophoresis analysis revealed that αs1-casein and β-casein were significantly hydrolyzed in most samples. The peptide extracts exhibited strong angiotensin-I-converting enzyme (ACE) inhibitory activity (>80 % in most samples), whereas their antioxidant capacity was relatively lower (15.36–20.42 % and 18.11–33.26 % by DPPH and ABTS assays, respectively). Among the tested microorganisms, the strongest antibacterial effect was observed against Listeria monocytogenes ATCC 7644. High GABA concentrations were detected in most cheeses, with 17 out of 25 samples exceeding 1000 mg/kg. Among the biogenic amines, tyramine, putrescine, cadaverine were predominant in the cheeses. Cheeses contained total biogenic amines at levels ranging from 16.74 mg/kg to 253.39 mg/kg. Overall, the findings indicate that moldy Civil cheeses exhibit noteworthy functional food potential, mainly attributed to their elevated GABA and bioactive peptide contents.