EXTENDING THE SHELF LIFE OF SOFT CHEESE USING ACTIVE RICE FLOUR/CARRAGEENAN FILMS FORTIFIED WITH DATE KERNEL EXTRACT

Abstract

This study aims to evaluate the biopreservative efficiency of active carrageenan rice flour films enriched with date kernel extract and to verify their applicability in extending the shelf life of soft cheese and ensuring its microbial integrity during refrigerated storage at 4°C for 21 days. Disc diffusion tests in agar revealed excellent inhibitory efficiency of the active films against bacterial strains contaminating cheese, including Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium. Cumulative release studies in fatty and acidic food mimics showed a gradual and controlled release of the active phenolic compounds, reaching its peak by day 21. This directly contributed to reducing the total number of microorganisms in the soft cheese and keeping it below the standard spoilage limit of 7 logarithms of colony-forming units per gram in the samples coated with the active films until the end of the storage period, compared to the uncoated control sample, which spoiled by day 17. In conjunction with microbial preservation, the active films successfully and significantly inhibited lipid oxidation reactions, and the diacid test values stabilized The thiobarbital content was below 1.5 mg/kg compared to the control sample, which positively impacted the stability of color indicators, sensory characteristics, and overall acceptability of the soft cheese, as well as protecting it from deterioration. These vital outputs demonstrate the success of the developed films as an active and sustainable packaging system capable of extending shelf life and ensuring the health and safety of high-moisture food products.