Extending the Shelf-Life of Processed Cheese Spread Using Propolis Extract

Propolis considered a natural product with an antimicrobial effect. Treating processed cheese spread with ethanol extract of propolis (EEP) was investigated by storage time. The treated with 200, 400, 600, 800 and 1000 mg of EEP/kg and control (non-treated) samples were stored at 5ºC /days. The quality of samples with respect to microbial, mycotoxin and sensory analysis every 5 days were evaluated. Gradual decrease of total mesophilic aerobic bacterial count, spore-forming bacteria and fungal count of the treated samples [(7.6 ~ 0.7) x 102 , (9.8 ~ 1.2) x 101 and (8.0 ~ 1.2) x 101 CFU/g)] showing substandard values throughout the storage time compared with the increasing control values [(7.6 ~ 9.3) x 102 , (1.1 ~ 3.0) x 102 and (0.8 ~ 1.3) x 102 CFU/g], respectively. Pathogens (coliform group, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Salmonella sp, Clostridium perfringens, and Listeria monocytoginis) were not detected in any of the samples. Aflatoxin M1 was affected by neither the concentration nor the storage time. Sensory evaluation showed a negative impact regarding propolis effect on color, taste, odor, texture and overall acceptance. EEP is recommended as a natural preservative in processed cheese spread regardless of its sensory effect.