【作者】 张波；

【导师】 李文浩；

【作者基本信息】 西北农林科技大学 ， 工程硕士（专业学位）， 2021， 硕士

【摘要】 辣椒红素和叶黄素是两种重要的类胡萝卜素,颜色鲜艳、安全性高、具有极大的生物学功能优势。辣椒红素被联合国粮农组织和世界卫生组织列为A类色素,在使用中不加以限量;叶黄素是存在于人眼视网膜黄斑区的主要色素。但由于结构中的多个共轭双键,导致水溶性和稳定性差,限制在工业上的应用。微胶囊技术利用天然或合成的材料（壁材）把气、液或固体材料（芯材）包覆成微小颗粒,可减少环境的干扰、减弱对机体的直接刺激、掩盖或延缓风味物质释放、提高芯材稳定性、转化为易处理的固体物质等功能。本研究用三种酯化改性方式（辛烯基琥珀酸酐、醋酸和柠檬酸酯化）处理淀粉,不同比例复配乳清蛋白和酪蛋白酸钠为乳化剂（蛋白质与酯化淀粉的比例分别为:10:0、9:1、7:3、5:5、3:7、1:9、0:10）,制备水包油型的辣椒红素/叶黄素乳液,利用喷雾干燥技术构建微胶囊。研究调控蛋白质和淀粉酯组分比例对微胶囊微观结构、理化性质和贮藏稳定性的影响。为拓展辣椒红素/叶黄素在食品、生物、制药等工业上的应用,提高其他脂溶性活性成分的稳定性、水分散性等提供参考。研究主要结果如下:（1）单一改性淀粉做乳化剂乳化效果较差,水包油型乳液体系呈现出较大液滴和聚集体;大部分微胶囊颗粒表面较光滑,相对完整,改性淀粉含量高的微胶囊产品表面出现孔洞和破损,蛋白质含量高的体系中无明显裂纹或孔隙。（2）微胶囊得率最高可达82.18%,随着壁材中蛋白质含量的减少而降低;水分含量均低于应用在食品领域干粉的最大含水量值3.00%～4.00%,达到较低水平;辣椒红素和叶黄素经微胶囊化后,溶解度显著提高至49.71%以上,且随着壁材中改性淀粉含量的减少,溶解度逐渐增大;本研究中三种壁材浸润于水的时间长短:酪蛋白酸钠>改性淀粉>乳清蛋白;微胶囊中改性淀粉含量最高的产品负载率较低,蛋白质的添加有助于提高微胶囊整体的负载率,改善包埋效果;负载率较高的微胶囊粉末产品的明度L*值也较高;辣椒红素微胶囊和叶黄素微胶囊的粒径分布范围分别为1～60μm和1～180μm,壁材中蛋白质含量较高的微胶囊的平均粒径较小,d_（4,3）和d_（3,2）值较为接近;微胶囊的玻璃化转变温度均高于室温,在一般的贮存条件下可以保持较稳定状态,且蛋白质的添加有助于提高微胶囊的热力学稳定性;乳液体系均是典型的非牛顿流体,稠度系数K（25°C）>K（50°C）,流体指数n（25°C）<n（50°C）。（3）光照和高温均可显著影响辣椒红素和叶黄素微胶囊的稳定性。三种辣椒红素微胶囊中,以乳清蛋白复配OSA马铃薯淀粉构建形成的微胶囊的保留率较高,贮藏稳定性较好;在三种叶黄素微胶囊中,以酪蛋白酸钠和醋酸绿豆淀粉复合作为壁材的叶黄素微胶囊贮藏稳定性较好,贮藏15天后保留率较高。更多还原

【Abstract】 Capsaicin and lutein are two important carotenoids with bright color,high safety and great advantages in biological functions.There are many functions in the capsaicin,such as weight loss,beauty,anti-aging and radiation protection.Capsaicin is listed as class A pigment by the Food and Agriculture Organization of the United Nations（FAO）and the World Health Organization（WHO）and there is no limit in use;Lutein is the main pigment in the macular area of the retina of eyes,which could reduce the incidence of cataracts and night blindness.However,the multiple conjugated double bonds in the structure resulted in the poor water solubility and stability of capsaicin and lutein,which limited the application in industry.Microencapsulation technology could use natural or synthetic materials as wall materials,and encapsulate gas,liquid or solid materials（core material）into small particles,which could reduce environmental interference,weaken the direct stimulation of the body,cover or delay the release of flavor substances,improve the stability of the core material and transform into easy-to-handle solid materials.In our study,starches were modified using three esterification methods（octenyl succinic anhydride,acetic acid and citric acid esterification）.Different ratios of proteins（whey protein and sodium caseinate）to esterified starch（10:0,9:1,7:3,5:5,3:7,1:9 and 0:10）were used as emulsifiers to prepare oil-in-water capsaicin/lutein emulsions,then microcapsules were prepared by spray drying technology.The effects of the protein and esterified starch ratios on microcapsule microstructure,physicochemical properties and storage stability were investigated.It provided reference for expanding the application of capsaicin/lutein in food,biological,pharmaceutical and other industries,and improved the stability and water dispersion of other lipid-soluble active ingredients.All results are as follows:（1）The emulsifying effect of single modified starch as emulsifier was poor,and the oil-in-water emulsion system presented larger droplets and aggregates.The surface of most microcapsule particles was smooth and relatively complete.The surface of microcapsules with high modified starch content appeared holes and damage,while the system with high protein content had no obvious cracks or pores.（2）The yield of microcapsules was up to 82.18%,which decreased with the decrease of protein content in the wall material;the water content was lower than the maximum water content of dry powder applied in the food field of 3.00%-4.00%,reaching a low level.After microencapsulation of capsaicin and lutein,the solubility of capsaicin and lutein increased significantly to more than 49.71%,and the solubility increased gradually with the decrease of modified starch content in the wall material.In our study,the soaking time of the three wall materials in water was:sodium caseinate>modified starch>whey protein.The product with the highest modified starch content in microcapsules presented lower load rates,and the addition of protein was helpful to improve the overall load rate of microcapsules and improve the embedding effect.The lightness L*value of microcapsule powder products with higher load rate was also higher.The average particle size of capsaicin microcapsules and lutein microcapsules ranged from 1-60μm and 1-180μm,respectively.The average particle size of microcapsules with higher protein content in the wall material was smaller,and the values of d_（4,3）and d_（3,2）were closer.The glass transition temperatures of microcapsules were all higher than room temperature,thus the microcapsules could be kept in a relatively stable state under general storage conditions.Moreover,the addition of protein was helpful to improve the thermodynamic stability of microcapsules.The emulsion systems were typical non-Newtonian fluids,K（25°C）>K（50°C）and n（25°C）<n（50°C）.（3）Light and high temperature could significantly affect the stability of capsaicin and lutein microcapsules.Among the three capsaicin microcapsules,the microcapsules constructed by combining whey protein with OSA potato starch had higher retention rate and better storage stability.Among the three kinds of lutein microcapsules,the lutein microcapsules using sodium caseinate and acetate mung bean starch composite as wall material processed better storage stability and higher retention rate after 15 days of storage.更多还原