【作者】 张波；

【导师】 魏益民；

【作者基本信息】 西北农林科技大学 ， 粮食、油脂及植物蛋白工程， 2003， 硕士

【摘要】 随着人们对健康、天然、绿色食品需求的不断增加，含有极高营养价值的苜蓿在食品中的应用逐渐受到人们的重视。加之西部大开发，退耕还草进程的不断推进，探讨苜蓿在食品中的应用，拓宽其应用领域有着非常现实的意义。 论文以关中紫花苜蓿为研究对象，分析了苜蓿、面粉、苜蓿面条及苜蓿膨化食品的营养成分，测定苜蓿面团的流变学及烘焙特性，苜蓿面条的蒸煮和感官品质，观察苜蓿面条、膨化食品的微观形态以及比较前人研究成果，得出以下结论： 1．第一茬返青后分枝期前苜蓿粗蛋白含量为35.21％，赖氨酸含量为1.59％，粗纤维含量为15.17％，均高于面粉；苜蓿第一限制氨基酸为蛋氨酸；矿质元素中铁含量为237mg·kg^-1，钙含量为17690mg·kg^-1，锌含量为36.8mg·kg^-1，硒含量为0.043mg·kg^-1；苜蓿粉中水溶性蛋白、盐溶性蛋白含量分别为10.93％、0.27％，占到苜蓿总蛋白的31.05％、0.76％； 2．随着苜蓿粉添加比例的增加，面团的吸水率增加，面团形成时间、稳定时间缩短，弱化度增加，面粉质量值降低；面团最大拉伸阻力、拉伸能量减少；所制面包比容下降。面筋含量高和面筋质量好的小麦面粉对苜蓿的添加耐受程度优于面筋含量低、质量差的小麦面粉。不同面粉的苜蓿添加范围应通过具体实验确定。 3．苜蓿粉可以提高面条和膨化食品的粗蛋白、粗纤维和矿质元素含量；面条和膨化食品中的粗纤维和粗蛋白含量与理论计算值的差距存在随加工温度和压力增加而增大的趋势。 4．面条的最佳煮制时间和蒸煮吸水率随着苜蓿粉添加量的增加而减小；面条的干物质失落率和蛋白质失落率随着苜蓿粉添加量的增加而增加。食盐对面条的干物质失落率的影响最大，其次为最佳煮制时间，食盐对蒸煮吸水率和蛋白质失落率的影响不大。 5．苜蓿添加量对于面条食味的影响达显著水平（a=0.05）。苜蓿粒度对于面条色泽的影响达极显著水平（a=0.01），对于面条食味、总评分的影响达显著水平（a=0.05）。在设定水平范围内，呈现苜蓿颗粒越细，面条总评分越高的趋势。加水量对面条感官指标的影响没有达到显著水平。除了韧性外，对各感官指标的影响顺序均为苜蓿粒度、添加量、加水量。对于韧性的影响顺序为苜蓿添加量、加水量、粒度。当添加量为7％，粒度为100目，加水量为吸水率的47％时，面条接受性最好。 6．在对淀粉糊化特性的影响中，挤压前苜蓿不增加也不减少粘度，主要减少淀粉糊的浓度并不影响原淀粉的糊化特性；挤压后膨化食品既出现冷水可溶，升温粘度下降等与预糊化淀粉特性相似的现象，也出现样品糊粘度低于水的粘度，峰值粘度升高等不同现象，原因有待于进一步研究。 7.通过电镜观察，能比较直观的观察到随首稽粉添加量的增加，面筋网络弱化度增加，面条内部结构疏松度增加等变化;在挤压面条和膨化食品中能观察到首蓓纤维，它有随加工温度和压力增加而减少的趋势，其他成分则无法分辨。 8要得到既营养又能接受的首稽面制食品，应选择筋性优于该面制食品要求的原料面粉，从而在添加一定量的首稽粉后，使其达到对原料面粉的要求，品质劣化在接受范围内，这条途径是完全可行的。更多还原

【Abstract】 After analyzing the nutrition of alfalfa, flour, spaghetti and extrudates, the rhoelogy and baking properties of dough, the pasta properties of starch, the cooking quality of spaghetti and describing the ultrastructure of spaghetti and extrudates, the application of alfalfa (Guanzhong variety) on cereal food was studied.The result was as follow:1.the protein content of fresh alfalfa which was harvested during middle April was 35.21%, the lysine, the fibre, the iron, the calcium, the zinc and the selenium content was 1.59%, 15.17%, 237 mg/kg, 17690 mg/kg, 36.8 mg/kg and 0.043 mg/kg separately. The nutrition which was mentioned above of alfalfa were higher than that of flour. The first limited amino acid of alfalfa was methionine whose content was 0.27%. The alfalfa contained 10.93% water soluble protein which was equal to 31.05% of total protein and 0.27% salt soluble protein which equaled to 0.76% of total protein.2. With increasing of alfalfa added, the capacity of water absorption and dough soften degree increased, while the dough developing time and stabilization time shortened, the maximum extension resistance and extension energy of the dough decreased, and the volum-to-weight of the bread dropped. The wheat flour containing more and finer gluten had more capacity for the alfalfa adding than the flour with less and poorer gluten. The range of alfalfa addition to a certain kind of flour should be determined by experiments.3. alfalfa had the ability to improve the nutritive value of spaghetti and extrudates by increasing their protein, fibre and mineral element content. The extent of protein and fibre content increasing was dropping with the temperature and pressure of extruding rising.4. With the increase of alfalfa added, the optimum cooking time and cooking absorption of fresh noodle shortened; cooking loss and cooking protein loss increased. The sodium content could increase the cooking loss and decrease the optimum cooking time and have a little influence on the cooking loss and cooking protein loss.5.The alfalfa addition significantly influence on the flavor of noodle(p=0. 05); the influence of alfalfa granularity on the noodle flavor and total grade was significant(p=0. 05), while on the noodle color was highly significant(p=0. 01). the water addition had no significant influence on the noodle sensory evaluation. The noodle was getting better when the alfalfa became smaller. The sequence of influence on the noodlesensory was the granularity, the alfalfa addition and the water addition with the exception of the noodle chewness whose sequence was the alfalfa addition, the water addition and the granularity of alfalfa. With the 7% alfalfa addtion, 100 mush alfalfa and 47% water absorption water addtion, the best noodle was obtained.6.the alfalfa decreased the maximum viscosity, the viscosity of holding period and cooling period, the final viscosity, the breakdown and the setback by diluting the starch concentration before extruding. After extruded, however, the extrudates was similar to the pregelatinized starch that was able to dissolve hi cool water and viscosity of which dropped when the temperature rising.7. With the increase of alfalfa added, through the scan eletron microscope, the fiber and the loosen of the interior structure of spaghetti could be observed directly, which could support some of the results such as the fibre content and the cooking loss was increasing.更多还原