No 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.

No abstract

The present study describes the effects of modified atmosphere packaging (MAP) on shelf-life extension, chemical, microbiological, and sensory properties of Domiati cheese. Five different MAP were studied [10% CO 2 /90% N 2 (G1), 15% CO 2 /85% N 2 (G2), 25% CO 2 /75% N 2 (G3), 100% CO 2 (G4), and 100% N 2 (G5)]. Control samples were packaged in air (CA) and under vacuum. In both groups of cheeses, chemical analysis was significantly affected by MAP during cold storage. Ripening indexes were significantly affected by MAP during cold storage. Microbiological data showed that G4, followed by G5, were the most effective groups inhibiting the growth of total aerobic mesophilic and psychrotrophic bacteria, and yeasts and molds until the end of storage. Sensory evaluation was significantly affected by MAP and storage period, at 45 d CA cheese samples were judged as unacceptable. The best sensory properties were obtained in G5, G4, and G3 treatments, and recorded a relatively higher sensory evaluation scores. The best shelf-life extension was obtained in G5, G4, and G3 treatments.

In the present study, the brewers spent grain BSG was used to supplement Yoghurt by displacement cow , s milk in ratios 0, 2, 4, 6, 8 and 10%. The proximate chemical composition, polyphenols and total flavonoids in BSG were determined. The resultant yoghurt samples were evaluated chemically, microbiologically and sensory fresh and stored at 4 0 C for 3, 7, 10 and 14 days. Significant differences in chemical, microbiological and sensory evaluation have been shown by increasing of BSG level in yoghurt. The addition of 10% BSG had the highest value of Total solids, Protein, Fat, Fiber, Ash and pH values but it had the lowest in Titratable acidity ,microbical count and sensory properties .