鱼骨纳米化加工过程中钙的释放机制研究

Superfine milling is one kind of important techniques which can be applied to process fish bone as high value-added products. In our previous studies, it was found that fish bone particle was downsized to nanometer range using high-energy wet milling and calcium release obviously increased. Furthermore, calcium release kept increasing with the milling time after the fish bone particle size reached a limit. So far mechanism on release of calcium from fish bone during the nano-milling process is unclear. In this study, nano fish bone (NFB) will be prepared from backbone of different fish species (silver carp, grass carp, catfish, tilapia, pollock, tuna and shark). Techniques such as energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, Fourier transform infrared spectrometer, reversed-phase high performance liquid chromatography, liquid chromatography/electrospray ionization tandem mass spectrometer will be applied for analyzing. Hierarchical structure of fish bone and kinetic of calcium release as affected by high-temperature treatment will be investigated. Effects of high-temperature treatment and nano-milling on collagen degradation and its molecular properties will be studied. The way of the collagen peptides chelating calcium released from the fish bone during the nano-milling process will be explored. And properties of the calcium-chelating peptides will be characterized. Finally the mechanism on release of calcium from fish bone during the nano-milling process will be concluded based on the results obtained from the studies above. The objective of this project is proposed to provide a scentific basis for development and application of fish bone products with high economic value.

超微细化是一种将鱼骨加工为高附加值制品的重要方法。前期研究证明采用高能湿法球磨可将鱼骨加工至纳米尺度并显著提高鱼骨钙的释放量，且发现鱼骨钙释放量在其粒径稳定后还会随着球磨时间延长而显著增加，鱼骨在纳米化加工过程中钙的释放机制尚不清楚。本项目拟以七种鱼骨（白鲢、草鱼、鮰鱼、罗非鱼、鳕鱼、金枪鱼和鲨鱼）为对象，采用X射线光电子能谱、场发射扫描电镜、傅立叶红外光谱、反相高效液相色谱和液相色谱/电喷雾电离/串联质谱等技术手段，研究高温预处理对鱼骨层级结构和钙释放动力学的影响，探明在纳米化加工过程中高温预处理和高能湿法球磨对鱼骨胶原蛋白降解和分子特性的影响，在此基础上探究鱼骨加工过程中生成的胶原肽与释放的钙离子之间螯合的作用方式及螯合产物的特性，从而阐明纳米化加工过程中钙的释放机制，以期为高附加值鱼骨制品的开发应用提供理论依据。

在鱼类加工过程中，约产生50%-70%的副产物。目前这些副产物主要是作为原料加工饲料或肥料等低附加值产品，部分副产物被厂家直接丢弃，不仅浪费原料，处理不当还会造成严重的环境污染问题。如何合理利用鱼骨等副产物成为水产品加工亟须解决的技术问题。本团队前期采用高能湿法球磨的方法制备出新型鱼骨制品-纳米鱼骨，该纳米鱼骨液为牛奶状乳白色液体，可直接加工成补钙制品或者广泛地添加于不同食品原料中，用于补充人体所需的钙。纳米鱼骨中钙的释放影响其生物利用价值和功能特性，因此深入了解球磨过程中鱼骨钙的释机制就显得尤为重要。因此，本项目研究了不同物种类骨（鱼骨、猪骨、牛骨和鸡骨）、不同鱼种类骨（白鲢、草鱼、鮰鱼、罗非鱼、鳕鱼、鲨鱼）和不同部位鱼骨（头骨、脊骨和肋骨）原料差异；预热对不同骨组成、力学特性、层级结构等特性的影响；采用高能湿法球磨制备纳米鱼骨，研究了预热处理方式、原料差异对纳米骨液的理化特性的影响；建立了鱼骨破碎动力学模型和球磨过程中钙离子释放动力学模型；进一步地，采用羟基磷灰石/胶原蛋白/氨基酸的模拟体系，研究了球磨过程中钙离子释放机制。纳米球磨通过促进羟基磷灰石（HAP）中钙的释放和新形成的钙化合物在水中的溶解来提高鱼骨中可溶性钙的含量。一方面，纳米球磨大大减小了鱼骨的粒径，增加了比表面积，使得HAP与水的接触面积大大增加。纳米球磨过程中，羟基磷灰石的晶体结构逐渐被破坏，钙通过水、氨基酸和肽的质子交换，有助于释放更多的钙。另一方面，鱼骨胶原被降解成肽和氨基酸，螯合释放的钙离子，导致可溶性钙含量增加。课题研究结果可为加工鱼骨为功能性钙制剂或者添加物等高附加值的产品提供了理论支撑。.在项目执行期间，发表学术论文6篇，其中SCI收录论文3篇，EI收录论文1篇，中文核心期刊论文2篇。参加国际学术会议3次、国内学术会议3次，并作分会场报告1次。培养博士研究生毕业1人，硕士研究生毕业2人，本科毕业生1人。