BackgroundChanges in colostrum composition of Egyptian buffaloes and Holstein cows collected at calving, 6, 12, 24, 48, 72, 96, 120 h and after 14 days of parturition were studied. Total solids, total protein, whey proteins, fat, lactose and ash contents were determined. Macro- and micro-elements, IgG, IgM, IGF-1, lactoferrin and vitamins (A and E) were also estimated.ResultsAt calving, the total protein and whey proteins concentration did not differ between buffalo and cow colostrum, while total solids, fat, lactose and ash concentrations were higher in buffalo than in cow colostrum. All components decreased gradually as the transition period advanced except lactose which conversely increased. On the fifth day post-partum, concentration of total protein, whey proteins, fat, ash and total solids decreased by 69.39, 91.53, 36.91, 45.58 and 43.85% for buffalo and by 75.99, 94.12, 53.36, 33.59 and 52.26% for cow colostrum. However, lactose concentration increased by 42.45% for buffalo and 57.39% for cow colostrum. The macro-and micro-elements concentration of both colostrums tended to decline slightly toward normality on the fifth day of parturition. Buffalo colostrum had a higher concentration of vitamin E than cow colostrum during the experimental period. At calving, the concentration of vitamin A in buffalo colostrum was found to be approximately 1.50 times lower than in cow colostrum. The concentrations of IgG, IgM, IGF-1 and lactoferrin decreased by 97.90, 97.50, 96.25 and 96.70% for buffalo and 76.96, 74.92, 76.00 and 77.44% for cow colostrum, respectively after five days of parturition.ConclusionsThere is a dramatic change in buffalo and cow colostrum composition from the first milking until the fifth day of parturition. There are differences between buffalo and cow colostrum composition during the five days after calving. The composition of both colostrums approaches to those of normal milk within five days after parturition.

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In this study, milk was hydrolyzed using protease (Asperigillus oryzae), trypsin, pepsin, or papain at concentrations of 0.001, 0.005, or 0.01 g/100 g milk for 30 or 60 min to produce angiotensin-converting enzyme inhibitory and antioxidant peptides. Results showed that the proteolysis, antioxidant, and ACE-I activity gradually increased with the increase in the enzyme concentration and hydrolysis time. The protease-treated milk had the highest proteolytic and ACE-I activity, while the papain-treated milk had the lowest. The papain-treated milk exhibited the greatest Fe 2+ chelating activity. The use of trypsin at concentration of 0.001 g/100 g milk for 60 min produced ACE-I and antioxidant activity without changes in the technological properties of milk.

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The objective of the current work was to evaluate the effect of three different commercial proteinbased fat replacers Prolo®11(PR), Simplesse®100 (SM) and Dairy Lo TM (DL) on the physicochemical, microstructural, and sensory characteristics of low-fat Edam cheese (LFEC) made from buffalo's milk during a specific ripening period. LFEC treatments were prepared using different ratios (0.3%, 0.6%, and 0.9% w/w marked I, II and III respectively) for each PR, SM and DL. Cheese without fat replacer was prepared as the control (C). Cheese containing fat replacers had a higher significant moisture content than C. Proteolysis significantly increased in LFEC containing Fat replacers more than C. Firmness decreased gradually with increasing the concentration of the fat replacers. PRIII and SMIII had less firmness. The addition of SM and PR improved texture, flavour and acceptability of the LFEC on the 60 th day of ripening. DL treatments achieved the best total scores for sensory characteristics on the 90 th day of ripening. Fat replacers affected the microstructure of LFEC especially SM which imparts a desirable texture to cheese, compared to other treatments.

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In this study, skim milk was fermented using 14 strains for 16 h at 42 °C or for 48 h at 25 °C. On conclusion of fermentation, the proteolytic, angiotensin converting enzyme-inhibitory (ACE-I), and antioxidant activities as well as the inhibition of thrombin and cholesterol micellar solubility were determined. The results revealed that B-4564 exhibited the highest ACE-I activity (68.11%) under the 42 °C for 16 h condition, while B-1445 demonstrated the highest ACE-I activity (92.23%) under the 25 °C for 48 h condition. B-4564 exhibited the highest inhibition rate of thrombin (42.43 and 48.10%) and cholesterol (68.60 and 87.01%) under the 42 °C for 16 h and 25 °C for 48 h conditions, receptively. B-442 exhibited the highest DPPH radical scavenging activity of 95.63 and 62.89% under the 42 °C for 16 h and 25 °C for 48 h conditions, receptively. B-1445 demonstrated the highest Fe chelating activity and reducing power under both the tested fermentation conditions.