PRODUCTION OF WHITE SOFT CHEESE FORTIFIED WITH NATURAL ANTIOXIDANTS AS A FUNCTIONAL DAIRY FOOD

This study was carried out to estimate the antioxidant activity and phenolic compounds of peanut skin, potato peels and rice bran extracts and to study the effect of addition of these natural extracts on soft cheese quality, each extract was added to cheese milk during manufacture at a rate of 0.5 to 1%. Cheese chemical composition, oxidative stability, microbiological examination and organoleptic properties of cheese, when fresh and after 30, 60 and 90 days storage at room temperature were done. Results showed that these extracts have a high content of phenolic compounds, and gave high antioxidtion activity. The addition of these extracts to cheese milk did not significantly affect on the chemical composition but affected the oxidative stability, bacteriological and organoleptic properties of cheese samples. A clear reduction was observed in peroxide value (PV), acid value (AV) and Thiobarbituric acids (TBA) content of cheese samples containing natural extracts during storage period than control cheese samples without antioxidant (control A) and those containing 0.02% Butylated hydroxyanisole (BHA) (as positive control B). Total bacterial, coliform and yeast and mould counts of cheese samples containing natural extracts did not detected during storage compared with control (A) cheese samples and those containing BHA as control (B). Also, results showed that organoleptic properties of all cheese treatments improved by progressed of storage period until the end of storage. Cheese containing potato peels and rice bran extracts at ratio of 1% showed better appearance, flavour intensity and body characteristics than other cheeses. From the previous results, some natural extracts could be used in white soft cheese manufacture such as potato peels, rice bran and peanut skin extracts at a rate of 1%, where it improved the sensory and bacteriological characteristics of cheese samples and increased stability against oxidation.