Utilization of Propolis Extract as A Natural Preservative in Raw Milk

Abstract

Natural antimicrobials have been considered of more importance due to their increase concerns among chemical preservatives among consumers. The effect on the quality of raw milk sample by different concentrations of propolis (5, 10 and20%) in water extract (WEP), stored at 30°C and 5±1°C was evaluated. pH value, titratable acidity and microbiological examination were detected. The addition of 2% water extract of propolis (20% extract) to raw milk resulted in acceptability of the milk up to 12 and 48 hours at 30 and5±1oC, respectively. Total bacterial count, coliform, molds and yeasts gradually decreased with the addition of more concentration of water extract of propolis (5, 10 and20%), compared with the control. The effect of 1,2 and 3% of water extract of propolis on the characteristics of yoghurt during storage(14 day) at 5±1°C were studied. Titratable acidity of T1 and T2 treatments increased, compared with the control. T3(3% water extract of propolis) resulted in the highest value of total phenolic compounds, flavonoids and antioxidant activity .Sensory evaluation revealed that yoghurt samples fortified with 1 and 2% of water extract of propolis resulted in the best treatments until the end of storage period.