Chitosan and Lemon Extract Applied during Giuncata Cheese Production to Improve the Microbiological Stability

In this study, lemon extract and chitosan were used as antimicrobial agents during Giuncata cheese production in order to assess whether the natural compounds would improve the cheese’s microbial quality. In particular, the viable cell concentration of the main spoilage microbial growth (Pseudomonas spp. and total coliforms) was monitored during refrigerated storage at 4 °C. A central composite design (CCD) was adopted to highlight a possible synergic effect of the two selected compounds. The results showed that a decrease in the cell growth rate of the monitored spoilage microorganisms was observed for all cheese samples added with active agents, when compared with the control cheese. Despite the recorded antimicrobial activity, an antagonist effect was detected when the two compounds were combined at the highest concentrations. In fact, the best performance was obtained when the lemon and the chitosan were used individually at concentrations of 500 and 60 ppm, respectively.