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Bovine plasma containing 7.9% proteins, is a valuable protein resource, This study took the bovine plasma as material. Processing technology of plasma proteins powder and processing functionalities of plasma proteins were studied. To study the process of processing conditions on properties of plasma proteins, the effects of heating temperature, protein concentration, pH, ionic strength on rheological properties, cooking loss, water holding capacity, gel strength, hardness, emulsifying capacity, foaming capacity of bovine plasma proteins were measured. The detailed contents and results are shown as follows:1. Spray drying process of bovine plasma proteins powderThe effects of centrifugation speed and time on the plasma separation process were investigated. The results showed that the centrifugation speed of 3000 r/min, centrifugation time was 30 min, the bovine plasma had yield large, high total protein content, and hemoglobin less residue. The effects of the inlet and outlet temperature on plasma spray drying process were investigated. The results showed that the inlet temperature of 180℃-190℃, the outlet temperature was 90℃, drying is better, plasma proteins powder had the lowest moisture content and the highest yield.2. Study on gel properties of bovine plasma proteinsThe effects of protein concentration, heating temperature, pH, ionic strength on bovine plasma proteins gel properties and rheological properties were investigated. The results showed that higher protein concentration would contribute to better protein gel, and the lowest concentration to form gel was 4%.When the heating temperature was 85℃,maintaining 20 min, the gel was smooth and elastic, with ideal gel properties. The gel strength would first increased and then decreased with the increamentof ionic strength,and at the concentration of 0.3M the gel strength reached the peak. When pH was 9.0, the gel properties were comparatively better with stronger gel strength, higher water holding capacity and lower cooking loss. NaCl and pH have significant interaction, and the bovine plasma proteins of 4.8% concentration have fine gel properties with adding 0.5M NaCl and adjusting pH to 9.0. 3. Study on emulsifying and foaming properties of bovine plasma proteinsThe effects of protein concentration, pH, ionic strength on bovine plasma proteins emulsifying and foaming properties were investigated. The results showed that:plasma proteins emulsifying and foaming capacity with protein concentration increased (P<0.05). When the pH9.0,0.3M NaCl, plasma proteins had the maximum emulsifying capacity and high emulsion stability. When the pH 5.0,0.5M NaCl, plasma proteins had the largest foaming capacity (P<0.05).4. Application of bovine plasma proteins in the sausage and the cakeApplication of bovine plasma proteins in the sausage and the cake were investigated. The results showed that:the sausage treatment group with 25% fresh plasma proteins substitution amount had high process yield, less total expressible fluid, high gel strength. The cake treatment group with 25% plasma proteins powder instead of egg protein had large special volume and less water loss during storage.
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