Tracking shelf-life determinants in soft, semi-hard, and hard cheeses: A quality perspective

Abstract

This study evaluates the physicochemical and microbiological quality indicators of 81 cheese samples (soft, semi-hard, and hard) produced in Iran, Saudi Arabia, and Turkey and marketed in Iraq. Samples were analyzed over storage periods of up to 60 days at 4 °C. Hydroxymethylfurfural (HMF) was quantified using HPLC-DAD, while total viable counts, Staphylococcus aureus, Escherichia coli , and yeasts/molds were determined by plate count methods. Antioxidant activity and reducing power of water-soluble extracts were assessed using DPPH and ferric reducing assays, respectively. Results showed a wide range of HMF content, with higher values generally observed in semi-hard and hard cheeses. Microbial analysis revealed that soft cheeses had the highest total viable counts and yeast/mold counts, though all values were within permissible limits except for some E. coli occurrences. Antioxidant activity and reducing power were highest in hard cheeses, particularly those from Turkey. Storage time significantly influenced moisture content and peroxide values across all cheese types. This study highlights considerable variability in cheese quality across origins and types. Findings support the need for routine quality control and stricter storage guidelines to ensure consumer safety.