Chemical and Antioxidant Properties of Rayeb Milk Fortified with Thyme and Almond Oils,

The effect of fortification of Rayeb milk quality with thyme and almond oils was investigated. ControlRayeb milk was made using Leuconostoc cremoris and Streptococcus lactis subsp. diaceteylactis culture.Eight Rayeb milk treatments were made fortified with 0.1%, 0.2%, 0.3% and 0.4% thyme and almond oils.Changes in chemical, antioxidant, viability of bacteria and organoleptic properties of Rayeb milk weremonitored during storage at 4º±1 for 7 days. The data indicated that essential oils had a slight effect on thetotal solids and fat %. The values of acidity showed significant (P< 0.05) increase and decrease in pH werenoticed in Rayeb milk samples during storage at 4º±1 for 7 days. Total free fatty acids content increased asincreasing essential oil ratios in all treated samples. All samples exhibited good radical scavenging activitywith varied degrees, However the highest values were shown with almond oil samples on the first day. Thegreatest antioxidant capacity was found in Rayeb milk samples enhanced with essential oils, as indicated bya significant increase (P<0.05) in total flavonoids (TF), total phenolic and (DPPH) radical scavenging.Meanwhile, the addition of essential oils improved the viability of lactic acid bacteria (LAB). The treatedsamples fortified with 0.1% and 0.2% of essential oil and the control of Rayeb milk gained the highestscore for organoleptic properties.