Study Of Porcine Haemoglobin Enzymolysis Decoloration Technique Optimize

Porcine blood is one of the main by-products of pork slaughter. Over 38% of the porcine blood cell is protein. The main protein of porcine blood is haemoglobin, more then 90% of all the porcine blood cell protein. Because of the color and odor of the haem, it will influence the sensual quality of the food if porcine blood cell is added in. So, the use of haem in food is limited.Till now, the mostly mathod of porcine blood cell protein discoloration are: Organic solvent method, oxide method, mechanical method, macromolecular compound flocculation method etc.. But of all the method, some is costly and difficult for industrialization; some is badly discolored, and badly destroy the odor and nutrition of protein.The technique of porcine blood cell protein decoloration with Alcalase enzymatic hydrolysis is studied in this thesis. Compared with other methods, the method of enzyme hydrolyzing has the following merits: thorough decoloration, low cost, easy to large-scale production and can be absorbed easily etc..1. According to such haemoglobin decoloration technique, a method for judging the effect of the decoloration of porcine blood cell protein was established. The Absorption value of decolored porcine hemo protein atλ=410nm (A410) is used to measure the decoloration effect.2. The method for measuring the degree of enzymolysis was established. The enzymatic hydrolysis final point is judged when 100g blood cell protein consumes 10ml 5mol/L NaOH solution.3. The parameters of decoloration technique were determined. An experiment with a single factor and regression analysis has been conducted to study the influence to decoloration effect from every factor, and the relevant mathematical models were established. Finally, a reasonable preparation technique was determine as follows:Enzymolysis process: fresh blood cell is first mixed with double amount of warm water, then adjust pH to 9.0, temperature to 57℃, then add Alcalase enzyme to such solution (the addition amount is 0.3% of fresh blood cell). During the reaction process, add 5mol/L NaOH solution in order to maintain the pH steadily. The enzymolysis final point is judged when 100g blood cell protein consumes 10ml 5mol/L NaOH solution.Decoloration process: after the enzymolysis, adjust the pH to 4.25 with 5mol/L HCl solution in order to inhibit the enzyme activity thus terminate the reaction. Flocculating the haem with 60 minutes still placement, and then centrifuging for 10min with a 7000r/min rotation rate. The supernatant solution is added with 2% activated carbon and then mixed for 10 minutes, then placed still and absorbed for 60 minutes. Again, centrifuging for 10min with a 7000r/min rotation rate. The light yellow supernatant solution is the needed enzymolysis protein solution. At last, adjust pH to 6.5~7.0 with NaOH solution. The paste of the decolored protein, which can also converted to protein powder by drying, is obtained by process of precipitating.4. Middle-scale experiments have been conducted to validate the reliability of mathematical models. These models can be used to predict the result thus conduct the practical production.