Red pepper–driven microbial and chemical shifts in feta cheese from a sheep and goat milk blend

Feta cheese is globally appreciated for its unique sensory profile, yet its high susceptibility to microbial contamination during handling poses significant preservation challenges. Incorporating natural plant-based additives represents a promising approach to extending shelf life without using synthetic chemical preservatives. This study aimed to develop a feta cheese matrix from a sheep and goat milk blend (70:30 ratio) fortified with crushed red pepper at varying concentrations (0%, 0.10%, 0.30%, 0.50%, and 1%). Cheese samples were manufactured under controlled pilot conditions and evaluated for biochemical and microbiological changes during refrigerated storage at 4 °C for 21 days. The control sample exhibited a gradual decline in protein, fat, and pH values over time. Conversely, red pepper fortification significantly minimized these changes (p < 0.05), particularly at 0.5% and 1% concentrations. Moreover, while counts of potentially contaminating bacteria (Salmonella spp., Escherichia coli, Staphylococcus aureus, Bacillus spp., and Pseudomonas spp.) and fungi increased progressively in the control, pepper-fortified treatments significantly reduced microbial loads to below detection limits (<10 CFU/g). Lactic acid bacteria counts were concurrently maintained, enhancing the functional quality. These findings demonstrate the high utility of crushed red pepper as an effective, natural bio-preservative to enhance the microbiological safety and quality retention of artisan cheese.