Research On Isolation, Phosphorylation And Related Properties Of Pork Hemoglobin From Pig Blood

In pig blood, there are abundant pork hemoglobins (PHb), which are cheap but valuable protein resource. In this paper, PHb is extracted from fresh pig blood, and then phosphorylated with STP. The best condition of phosphorylation is discussed and further study of the proterties of the PHb is made.In this paper, the methord of isolating PHb from fresh pig blood is determined. To compare the result of salting separation and that of membrane separation, related physical and chemical characters are tested. It shows that the PHb extracted by the two methods are similer in any aspect, with the salting separation more suitable for experiment in lab while the membrane separation more suitable for industrial ways.In this paper, the optimal condition of phosphorylation is discussed. Through the separated factors experiments and orthogonal experiments, the optimal condition of phosphorylation is set as follows: the content of PHb 8%, pH 9.0, STP content 10%, and time 1h. The influence of STP content and PHb content is significant(P<0.05), while the influence of time and pH otherwise(P>0.05). The level of influence of the four factors is desided as: STPcontent >PHb content >pH >time. The further study of optimal condition of phosphorylation with the aid of ultrasonic is discussed. The optimal condition of phosphorylation is set as follows: the temperature 30℃, pH 8.5, STP content 10%, and time 45min. The influence of STP content and temperature is significant(P<0.05), while the influence of time and pH otherwise(P>0.05). Under that condition, the phosphorylation level is 79.2mg/g.In this paper, the properties of PHb both before being phosphorylated and after that are studied, like how the solubility, emulsifying and the stability of emulsifying, foaming and stability of foaming and so on, change according to the different conditions in which pH and NaCl content vary. It turns out that, the properties of PHb phosphrylated change to some degree. In most cases, the characteristics of the PHb phosphylated such as the solubility, the emulsying and the stability of emulsifying, foaming and stability of foaming are superior to those of the PHb without being phosphylated. This phenomenom attributes to enlarge the range in the food industry.In this paper, through the infrared absorption spectrs, it shows thatε-NH₂ of lysine reacts to phosphate. Through the SDS-PAGE, it shows that the PHb phosphylated does not change, whose molecular weight is 64000D.In this paper, the effect on the texture of sausage which contains PHb phosphylated is studied. SPI, PHb and PHb phosphylated are separately added to the sausage with different content of 0.5%, 1.0%, 1.5%, and 2.0%. When tha storage time continued to ten to fifteen days, the texture of the sausage changed evidently.