提高微量营养素混合均匀度的方法研究

发布时间：2018-07-22 10:04

【摘要】：将单体营养强化剂或预混的多种营养强化剂按要求加入到某种食物载体中即为食物强化。食物强化是营养干预的主要手段。粉粒体状食物的强化要求营养强化剂在食物载体中应均匀分布。粉粒体状强化食品的生产是一个基于多种不同物性颗粒粉体混合的复杂过程,明晰粉粒体混合的基本原理及易造成粉粒体混合物分级的主要原因,能够为生产合格的粉粒体状强化食品奠定重要技术基础。于是我们基于粉粒体物性开展了一系列实验。 1.营养素强化剂单体、辅料、食物载体的物性指标测定目的明晰影响粉粒体混合的物性因素,对实验粉体的各项物性指标逐一测定,完成营养素单体物性数据查询软件。方法以GB14880-2012及行业使用习惯为依据,全面收集粉粒体状营养素强化剂单体、预混料生产常用辅料、法规允许使用的食物强化载体。使用相应方法对所涉粉体的介观图片、电镜图片、粒度分布、有效密度、Carr流动性指数、Carr喷流性指数、吸湿性进行逐一测定。结果课题共收集各类样品126个,通过对各样品所涉物性指标的测试比较,营养素预混料和强化食品生产中所涉的各类粉体在微观形貌、流动性、喷流性、吸湿性等方面均表现了较为明显差异。以此数据为基础,分类整理后开发了营养素物性数据查询软件。结论不同粉体的物性差异应是影响混匀度的根本原因。 2.粉体混合均匀度预估经验公式的建立目的建立粉体分形维数与粉体中目标物含量变异系数间的数量依存关系,以期形成混合均匀度经验预测公式。方法以分形维数表征粉体粒度分布数据,通过对相似性质粉体的筛分,按照不同配比得到不同分形维数的两相混合粉体,使用原子吸收法测定不同实验组中目标物含量变异系数,进而建立分形维数与变异系数间的量化关系,数据拟合后得到计算公式。结果分形维数与变异系数的数据拟合结果显示,二者间有高度的相关性(p0.05),得到了混匀度预测经验公式,但该公式的使用范围受限,需进一步修正。结论初步实现通过粒度分布数据预测混合均匀度的目的。 3.物理包覆法改善预混料混合均匀度目的通过干法包覆实验实现营养素在预混料及强化食品中的均匀分布。方法使用气流磨在不同参数条件下对部分营养素进行超细粉碎实验,通过粉碎前后粒度分布数据评价粉碎效果并探讨不同颗粒粉碎特性。将经超细粉碎的营养素强化剂单体作为子颗粒,麦芽糊精作为母颗粒,分别在不同条件下投入高速气流冲击式粒子复合化系统中进行物理包覆实验,通过包覆前后的电镜图片及粒度分布数据评价不同营养素包覆效果,并进一步通过混合操作对子母颗粒包覆强度进行考察。最后,通过比较添加营养素原料及营养素包覆颗粒后强化面粉中目标营养素含量的变异系数,评价物理包覆技术对改善强化食品中微量营养素混合均匀度的有效性。结果通过对NaFeEDTA的超细粉碎实验,选定了气流磨的气流压力为8Mpa时粉碎效果最佳。通过对超细粉碎后的NaFeEDTA进行包覆实验,确定了子颗粒15%添加量、叶片转速45hz、包覆时间10min的包覆条件。在选定条件下,对CaCO3、 ZnO、VB(硝酸硫胺素)、VB2、烟酰胺、叶酸分别进行超细粉碎及包覆实验,结果显示,矿物质类颗粒的包覆效果要优于维生素类颗粒。经NaFeEDTA、CaCO3、ZnO包覆后的颗粒具有较好的子母颗粒结合强度,微量营养素在包覆过程中损失较小,回收率都在90%以上。使用包覆超细NaFeEDTA、CaCO3后的粒子对面粉进行强化后,较之使用未处理营养素的强化方法,微量营养素含量变异系数都有了较为显著的降低,降低程度都在50%以上。结论使用气流磨对营养素强化剂单体进行超细粉碎,超细营养素通过物理包覆方法能产生较为稳定的新粒子,以此新粒子进行食物强化的方法能较为有效改善强化食品中微量营养素的混合均匀度。
[Abstract]:Food intensification is the main means of nutrition intervention by adding a variety of nutritional fortifier or premixed fortifier to a certain food carrier. Food strengthening is the main means of nutrition intervention. The strengthening of the silt like food requires that the nutritional fortifier should be evenly distributed in the food carrier. The complex process of the mixing of the homogeneous particle powders, clarifying the basic principle of the mixing of the particles and the main cause of the classification of the powder mixture, can lay an important technical basis for the production of qualified silt shaped fortified foods.
1. determination of physical properties of nutrient enhancer monomers, excipients and food carriers
Objective to clarify the physical factors affecting the mixture of powder particles, to determine the physical properties of the experimental powder one by one, to complete the data query software of the nutrient monomer, based on the GB14880-2012 and industry usage habits, to collect the silt nutrient fortifier monomers, the premixture to produce common excipients, and the laws allowed to be used. Use the corresponding methods to determine the mesoscopic pictures, electron microscope pictures, particle size distribution, effective density, Carr fluidity index, Carr jet index and hygroscopicity of the particles involved. Results 126 samples of various samples are collected, and the nutrient premixture and fortified food are compared by the test and comparison of the physical indexes involved in the samples. The various kinds of powder involved in the production showed obvious differences in micromorphology, fluidity, jet and hygroscopicity. Based on this data, the data query software of nutrient substance was developed after sorting and sorting. Conclusion the difference in physical properties of different powders should be the fundamental cause of mixing degree.
The establishment of an empirical formula for predicting the mixing uniformity of 2. powders
Objective to establish the dependence relationship between the fractal dimension of powder and the coefficient of variation of object content in powder, in order to form the empirical prediction formula of mixing uniformity. The coefficient of variation of target content in different experimental groups was measured by atomic absorption spectrometry, and then the quantitative relation between the fractal dimension and the coefficient of variation was established. The calculation formula was obtained after the fitting of the data. The results of data fitting between the fractal dimension and the coefficient of variation showed that there was a high correlation between the two (P0.05), and the empirical formula of mixing degree prediction was obtained. This formula is limited in scope of use and needs further correction. Conclusion the initial goal is to predict the mixing uniformity through particle size distribution data.
3. physical coating method to improve mixing uniformity of premixture
Objective to realize the uniform distribution of nutrients in the premixture and the fortified food by the dry coating experiment. The method used air mill to carry out ultrafine crushing experiment on some nutrients under different parameters, and evaluated the crushing effect by the particle size distribution data before and after comminution and discussed the comminution characteristics of different grains. As the seed particles and malt dextrin as the parent particle, the physical encapsulation experiment was carried out in the high-speed airflow impact particle composite system under different conditions. The effects of different nutrients were evaluated by the electron microscope pictures and particle size distribution data before and after the coating, and the sub parent particles were coated further through the mixing operation. In the end, the effect of physical coating technology on improving the uniformity of micronutrients in the fortified food was evaluated by comparing the coefficient of variation of nutrient raw materials and nutrients coated particles, and the effect of physical coating technology on improving the uniformity of micronutrients in the fortified foods was evaluated. The air flow mill gas was selected through the ultrafine grinding experiment of NaFeEDTA. The crushing effect is the best when the flow pressure is 8Mpa. By coating the NaFeEDTA after superfine comminution, the addition of 15% subparticles, the speed of the blade 45Hz, the coating time of the coating time 10min are determined. Under selected conditions, the experiments of ultra-fine comminution and encapsulation of CaCO3, ZnO, VB (Thiamine nitrate), VB2, smog amide and folic acid are carried out respectively. The results show that The encapsulation effect of mineral particles is better than that of vitamins. After NaFeEDTA, CaCO3, ZnO coated particles have good bonding strength, micronutrients have less loss in coating process and the recovery rate is above 90%. The use of superfine NaFeEDTA coated particles after CaCO3 is not used. The variation coefficient of micronutrient content has been significantly reduced and the degree of reduction is all above 50%. Conclusion the use of air flow grinding to the superfine grinding of nutrient enhancer monomer, superfine nutrients can produce more stable new particles through the physical coating method, and the new particle can be fortified by the new particle. The method can effectively improve the mixing uniformity of micronutrients in fortified foods.
【学位授予单位】：中国疾病预防控制中心
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R151

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