Study of Preservative Effect of 'Propolis' on the Storage Quality of Mashed Potatoes

摘要

In this study, the possibility of natural antimicrobial compounds, Jordanian propolis as food preservatives is investigated. The experiment was conducted in the laboratories of basic science-allied medical science, at applied science university during April –July 2013 to optimize the preservative for safe storage of mashed potatoes preparing from fresh boiled potatoes. Approved chemical preservatives have been widely used to preserve foods and increase their shelf life. There are increasing demands of the partial or complete removal of chemical preservatives from foods because of adverse health effect of chemicals. Propolis sample was collected from naour region. The antimicrobial activities of propolis against several food spoilage microorganisms were examined. Escherichia coli, Bacillus cereus, Candida albicans, and Staphylococcus aurous, as food poisoning microorganisms were chosen. The post-processing development of contaminating microorganisms present in stored mashed potatoes was controlled effectively with 100, 200, and 400ppm of Jordanian propolis. Among these preservatives, 400ppm honey gum showed better sensory quality attributes in respect of color, flavor, texture and taste during four months of storage at room temperature, which is better than 400 ppm of sodium benzoate preservatives. Antimicrobial effect was tested during storage at 25℃. When the microorganisms were treated with propolis, the population of food spoilage microorganisms decreased by 2.6-3.7 log cycles. The inhibitory effect was increased in more acidic condition. Propolis was effective at preventing microbial growth and extending shelf-life.