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This study was carried out to clear the effect of addition of pomegranate and lemon peel extracts as natural antioxidant on Feta like cheese quality. These extracts were added to cheese during manufacture at a rate of 0.25 and 0.50% of each extract. Cheese treatments were analyzed for chemical analysis, oxidative stability, microbiological examination and organoleptic properties, when fresh and after 7, 14, 21 and 28 days of storage at refrigerator temperature. Results showed that these extracts have a high content of phenolic compounds, and gave high antioxidant activity. As well as the addition of these extracts to cheese did not significantly affect the chemical composition but affected the oxidative stability, bacteriological and organoleptic properties of cheese samples. A clear reduction in peroxide and acid values of cheese samples containing natural extracts during storage period than control cheese samples where observed. As well as total bacterial, coliform, as well as yeast and mould counts of cheese samples contain natural extracts did not detected during storage compared with control cheese samples. Also, results showed that organoleptic properties of all cheese treatments improved by progressed of storage period until the end of storage. Cheese containing lemon peels extracts showed lowest flavour intensity and body characteristics than other cheese. From the previous results, it could be recommended the use of some natural extracts in feta like cheese manufacture such as pomegranate and lemon peel extracts at a rate of 0.5%, where it improved the sensory and bacteriological characteristics of cheese samples and increased stability against oxidation.

Purpose:The present study investigated AFM 1 contamination in raw milk, kareish cheese and yoghurt and studied the abilities of heating and probiotic bacteria to reduce AFM 1 contamination in both raw milk and yoghurt. Methods: AFM 1 was detected in raw milk in 10 of 12 samples (83.3%) from each season. Two methods were used to assess the toxigenic potential. HPTLC was performed for aflatoxin detection. Aflatoxin M 1 contamination milk and selected dairy products was investigated against heating and Lactobacillus acidophilus La 5 and Bifidobacterium lactis Bb 12 and its combination. Result: Cheese had the highest mean values concentration of AFM 1 (527.4 and 651.3 ng/kg), and yoghurt had the lowest concentration (39.13 and 64.68 ng/kg) while, raw milk samples were (207.0 and 311.8 ng/kg) during summer and winter, respectively. The concentration of toxin in 83.33% of the examined cheese samples exceeded the EU limit (50 ng/kg), and 70.83% of these samples exceeded the Codex limit (500 ng/kg) during both seasons. Boiling degraded 26.71% of the AFM 1. Whereas, pasteurization only degraded 15.45%. In yoghurt, two strains of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium lactis) each gradually reduced the AFM 1 concentration as a function of time in milk contaminated with 25 ng/l, with complete elimination by the end of the refrigerated storage period (3 days), while, the combination of both probiotic bacteria (L. acidophilus and B. lactis) was better able to reduce AFM 1 in milk contaminated with 50.0 ng/kg or 75 ng/kg AFM 1 .Conclusion: The most extensive reductions of the AFM 1 concentration were to 41.80 ng/kg (45.3%), 22.6 ng/kg (69.90%) and 7.12 ng/kg (92.8%), which were achieved using the same concentration of each strain individually and in combination, respectively, after two days in milk contaminated with 75 ng/kg. No AFM 1 was detected after three days using the combined strains.

The present study was carried out to estimate the effect of ginger rhizomes (Zingiber officinale) extracts on the oxidative stability, chemical composition, microbiological and sensory properties of UF-soft cheese being made with aqueous or ethanolic ginger extracts (1%) compared to control cheese and cheese contained 0.02% of butylated hydroxy anisole (BHA). Resultant cheeses were stored in brine solution 6% at 7±1°C up to 90 days. Results showed that, addition of ginger rhizomes extracts had increasing significant effect (P≤0.05) on fat/DM%, soluble nitrogen (SN/TN%) and non protein nitrogen (NPN/TN%). On the other hand, titratable acidity, total protein%, salt in moisture% and total volatile fatty acids (TVFAs) were decreased with addition of aqueous or ethanolic ginger extracts compared to control cheese and cheese treated with BHA as synthetic antioxidant. Cheese containing 1% ethanolic extract showed the highest oxidative stability. Also, ginger extracts reduced the total bacterial count than the control and BHA treatment. However, yeast and mould counts showed opposite trend and they were not detected in all treated samples up to 60 days of storage. Also, results showed that, cheese samples containing ginger ethanolic extract (1%) showed better organoleptic characteristics than other treatments. From the previous it is advanced to use ginger extract in manufacture of white soft cheese at the rate of (1%).

The present study was carried out to determine the vital compounds in the Moringa peregrina leaves ethanolic extract (MPLEE) and estimate the effect of that extract on the oxidative stability, chemical composition, microbiological and sensory properties of UF-soft cheese made with MPLEE at different concentrations (10, 20 and 50 mg/ml) compared to control cheese and cheese contained 0.02% of butylated hydroxy anisole. The results showed that the yield of extract was 35% of dry weight of leaves, Total phenolics (116.6 mg chlorogenic acid equivalents /g extract) and total flavonoids (45.2 quercetin equivalents/g extract). The main components for MPLEE were rutin, narengin, rosmarinic and hisperdin (17412, 1328, 1047 and 984.90 mg/L, respectively). The concentration of the sample that scavenges 50% of the DPPH radicals (SC50) of MPLEE was recorded 500 µg mL-1. Results showed that, addition of MPLEE had increasing significant effect (P≤0.05) on fat%, Nitrogen fractions%, salt% and total volatile fatty acids. On the other hand, titratable acidity was decreased with addition of the ethanolic extract compared to control. Cheese containing MPLEE showed the highest oxidative stability. Also, the extract reduced the total bacterial and coliform count in all samples. However, fungi counts showed opposite trend and they were not detected in all treated samples up to 60 days of storage. Results also showed that cheese samples containing MPLEE showed better organoleptic characteristics than other treatments. It could be recommended to use this extract at level of 20 mg/ml as a useful additive to improve the microbiological quality and shelf life of the product