The response surface optimization on ultrasonic extraction process of porcine hemoglobin and effect of ultrasonic process on its structure

The ultrasonic extraction of hemoglobin from porcine blood was studied in this paper. With the yield of hemoglobin from red blood cell as evaluation index,the influence of amplitude and time of ultrasonic,ratio of quiescent intexal to impuse excitation time and volume ratio of water to red blood cell on the extraction process of hemoglobin were investigated by single-factor tests. The optimum extraction conditions were obtained through the Box-Behnken response surface:Ultrasonic amplitude of 26%,ultrasonic time of 10.15 min,quiescent interval to impulse excitation time ratio of 2∶1,water to red blood cell ratio of 4.25∶1.On this optimum extraction process conditions,the hemoglobin yield reached 91.4763%. In addition,the effect of ultrasonic process on hemoglobin structure was also investigated. The spectrum of UV-Vis,FTIR,Confocal Micro-Raman and circular dichroism were used to research the change of hemoglobin structure especially the structure of porphyrin ring. The main conclusion derived from this study was that ultrasonic extraction had an influence on the secondary structure of hemoglobin,it could cause the exposure of heme center from hydrophobic pocket,but the porphyrin rings remain intact. This research provided the optimal extraction process of porcine hemoglobin and could provide the theory basis for the further study of preparation and structural research of porphyrins compounds.