Enhancing Kope cheese with phycoerythrin: microbial, physicochemical, sensory, and antioxidant insights

This study assessed the potential of phycoerythrin (PE) extracted from Desmonostoc alborizicum FA1 as a natural preservative in Kope cheese, a traditional dairy product from Kurdistan. The aim was to explore PE's effects on microbial, antioxidant, physicochemical, and sensory properties of cheese as a sustainable alternative to chemical preservatives. After extraction and semi-purification, PE was added to fresh cheese at concentrations of 1%, 1.5%, and 2% (w/w), alongside a control. The cheeses were stored at 4 °C for 60 days and analysed for various properties. PE significantly reduced the total plate count (TPC) over time. All PE-treated samples showed lower microbial counts compared to the control, with the 2% PE treatment showing the most effective reduction. Furthermore, physicochemical characteristics, such as colour (a* and b* values) and water-holding capacity (WHC), improved. Antioxidant activity was also enhanced, indicated by increased FRAP values, higher DPPH radical-scavenging activity, and reduced nitric oxide levels. Sensory evaluation showed no significant changes in taste, aroma, or texture due to PE addition. These effects are likely due to interactions between PE bioactive compounds and cheese proteins. Overall, PE demonstrates promising potential as a natural, bio-based preservative for dairy products, potentially reducing the dependence on chemical preservatives.