The present study was carried out to evaluate the antimicrobial and antioxidant effects of black tea extract (BTE), green tea extract (GTE) and carob extract (CRE) in buffalo butter during storage at 4±1ºC for 12 weeks and compare to synthetic phenolic compound butylated hydroxytoluene, (BHT). The antibacterial effect and minimal inhibitory concentration (MIC) of extract against Listeria monocytogenes were studied. The effectiveness of these extracts (0.025 -0.05%) in butter made from pasteurized cream were evaluated by incubating (10 5 cfu/g) of Listeria monocytogenes. The GTE had completely inhibited (P≤0.05) the viability growth of Listeria monocytogenes during storage at 4±1ºC (10 -12 weeks) . During storage of butter made from unpasteurized cream, the population of lipolytic bacteria and mould&yeast markedly reduced (P≤0.05) by addition GTE (0.025 -0.05%) compared to other treatments. Also, BHT (0.025%) and GTE had similar inhibitory effect on Staph. aureus. E. coli and total counts. The BTE and GTE had a most antioxidant effect on decreasing the acid value (AV), peroxide value (PV) and thiobarbituric acid value (TBA). While CRE had less effect. Organoleptically, butter with added BTE, GTE and CRE gained the highest acceptance until 8 weeks compared with BHT treatment and control sample. This research has demonstrated that the use of BTE and GTE as a natural antimicrobial and antioxidant is a promising means to provide additional safety and improve the quality of buffalo butter during storage.

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Electron spin resonance (ESR) spectroscopy has been used to assess the free radicals signal in different milk powders, buffalo's, cow's goat, camel, commercial full cream cow's milk powder, buffalo's butter milk and colostrum before and after γray irradiation at does 1 and 2 KGy. Non-irradiated milk samples exhibited weak signal intensity, depending on the type of milk. However, ESR signal intensity of all irradiated milk samples gradually increased as the radiation dose increases from 1 to 2 KGy. The results showed that the radio-stability of milk powder depended on the original free radicals and radiation dose applied. Buffalo's butter milk and camel milk powders had the highest radio-stability, while buffalo's milk powder was the lowest. The results of this study recommended to use ESR as a new technique in evaluation quality control dairy products during processing and storage.

The compositional and functional properties (i.e., solubility ,water-holding and fat-absorption capacity, electroconductivity and emulsification capacity, and stability) as well as digestibility by trypsin of buttermilk solids (BMS) and buttermilk protein preparations (i.e., buttermilk whey protein concentrates, BMWPC ; buttermilk caseinco-precipitate, BMCCP ; total buttermilk protein, TBMP and buttermilk acid casein, BMAC) were studied. The effect of different pH levels on solubility, electroconductivity and emulsification capacity and stability was evaluated. All samples were similar in their chemical composition as they contained protein, lactose, fat and ash. BMS had higher fat, lactose and ash content and lower protein content compared with those of other dried buttermilk protein powders. Except electroconductivity and solubility, BMS showed limited functional properties in fat-absorption capacity (0.66 g fat/g protein) and emulsifying capacity (0.373-0.543, O.D) and stability (34-37 min.) at low pH (pH≤5) while , BMWPC had the highest fat-absorption capacity (2.5 g fat/g protein) and emulsifying capacity(0.400-0.800, O.D) and stability(38-44 min.) at the same pH , furthermore, its high digestibility by trypsin. This could be due to the heat treatment applied during preparation of BMWPC. So, BMWPC appears to be a promising and unique ingredient in the formulation of low pH foods.

The yield, composition, organoleptic, textural and microbiological properties of Egyptian style low-fat white soft cheeses made of skim buffalo's milk (0.1%F) by adding fat replacers (hydrocolloids); 0.07 & 0.1% w/w Xanthan gum (XG), 0.5 & 0.75% w/w Tragacanth gum (TG) and 0.5 & 1% w/w Maltodextrin (MD) were evaluated and compared with their counterpart low & full fat control cheeses (LFC & FFC). All of the low-fat products reduced the yield, F/DM, Ash/DM, M:P and MNFS, whereas the moisture content, P/DM, and pH significantly increased. However, the cheeses containing hydrocolloids had higher moisture and yield values than their control LFC with respect to the type and concentration. The mean values of TPA (texture profile analysis) improved the cheese texture parameters, when the hydrocolloids were included. This was clearly evident by sensory evaluation. The replacement of fat by these hydrocolloids caused a significant increase of the total, proteolytic and lipolytic bacteria counts and moulds & yeasts of cheese. The fresh full-fat white soft cheese was perceived as more elastic, less salty and had higher flavor and odor scores than all low fat variants. It could be concluded that by using hydrocolloids significantly enhanced all organoleptic parameters to gain higher total scores, as compared with control LFC, and to be more close to their corresponding control for XG cheeses (91.04 & 89.06 vs. 91.80).