瞬时弹射式蒸汽爆破法制备速溶牦牛骨粉及其理化特性

为解决骨粉的难溶解性及制备耗时问题,该研究采用瞬时弹射式蒸汽爆破(instant catapult steam explosion,ICSE)技术制备速溶牦牛骨粉,并与常规球磨牦牛骨粉进行理化特性比较分析。通过观察不同压力(0.5~1.5 MPa)和不同保压时间(5~30 min)ICSE条件下牦牛骨的液化情况及骨粉得率,以确定牦牛骨粉的制备条件,并通过骨粉化学结构、粒度分布、微观形态、稳定性、蛋白质溶解性和钙离子释放度的测定对比分析了速溶牦牛骨粉和常规球磨骨粉的理化特性。结果显示:1.5 MPa 30 min ICSE条件下制备的骨粉(<500目)得率可达46.16%;与常规球磨牦牛骨粉相比,ICSE牦牛骨粉化学结构无明显变化,但其中值粒径(5.61μm)明显较小(P<0.05),粒度分布均匀并呈正态分布,微观形态均匀规则;ICSE牦牛骨粉的蛋白质溶解度在37、60和100℃条件下分别为97.17%、95.29%和82.07%,均明显高于球磨骨粉(4.07%,6.47%和10.17%)(P<0.05);ICSE牦牛骨粉钙离子释放度为67.42 mg/g,高于常规球磨骨粉(14.25 mg/g);此外,短时间内ICSE骨粉悬浮液在室温条件下无明显沉淀,其溶解性和稳定性优于球磨骨粉。ICSE法制备速溶牦牛骨粉解决了骨粉制备耗时长、溶解性差等问题,为骨粉的制备提供了一种新方法。

Preparation of instant yak bone powder by using instant catapult steam explosion and its physicochemical properties

In order to solve the problem of insolubility of bone powder and improve preparation process,the instant yak bone powder was prepared by liquefying yak bone with instant catapult steam explosion(ICSE),and the elemental nutrients and physicochemical properties of which were also analyzed comparing with the bone powder prepared by traditional ball-milling method.Firstly,according to the liquefaction rates of yak bone and the yields of bone powder under different pressures and maintaining times,the best ICSE condition was selected.The yields were calculated based on dry material after sieving and spray drying.Then,the physicochemical properties including the chemical structure,particle size distribution,micro-morphology,instant solubility,sedimentation,protein solubility and calcium release of yak bone powder were analyzed and compared.The results showed that the highest yield of yak bone powder was 46.16%prepared by ICSE technology under 1.5 MPa for 30 min.Therefore,the instant powder was prepared by this condition,and its nutritional components and physicochemical characteristics were analyzed.By analyzing the molecular weight distribution of peptides in liquefaction under 1.5 MPa for 30 min,it was found that bone collagen was broken into peptides with different molecular weights,and the peptides with molecular weight less than 0.5 kDa accounted for 26.14%.Also,we found that the bone microstructure treated by ICSE was looser and more porous observed by scanning electron microscope.Compared with the ball-milling yak one powder,the chemical structure of ICSE yak bone powder had no obvious change since the peak positions of Fourier infrared spectroscopy were similar.The median particle size of ICSE yak bone powder was 5.61μm,which was significantly smaller(P<0.05)than that of ball-milling yak bone powder,and the particle size distribution was more uniform because of the regular normal distribution while the median particle size of ball-milling yak bone powder was 19.68μm with a skewed distribution.Through the determination of basic ingredients of yak bone powder,it was found that both protein and fat contents of yak bone powder prepared by ICSE were significantly(P<0.05)higher than that of ball-milling yak bone powder while ash was less.Meanwhile,the contents of main minerals such as P,Ca,Mg,K,Zn decreased significantly(P<0.05)in ICSE yak bone powder while that of Na increased significantly.Additionally,the ICSE yak bone powder had better solubility and stability than ball-milling yak bone powder.It is soluble in water at room temperature,and no obvious precipitation occurs within 10 minutes.Comparatively,it gradually became clear and transparent with the extension of time for ball-milling yak bone powder.Besides,the protein solubility of ICSE yak bone powder increased significantly(P<0.01),which were 97.17%,95.29%,82.07%at 37℃,60℃,100℃while the ball-milling yak bone powder were 4.07%,6.47%,10.17%,respectively.In addition,the calcium release of ICSE yak bone powder could reach 67.42 mg/g while that of ball-milling yak bone powder was only 14.25 mg/g.The ICSE method for preparing instant yak bone powder can shorten the preparation time and improve the product quality.Therefore,ICSE technology can be used as a new and efficient method to improve the value of bone byproducts.