【作者】 刘春燕；

【导师】 邬应龙； 陆胜民；

【作者基本信息】 四川农业大学 ， 食品科学， 2007， 硕士

【摘要】 豆芽不但营养丰富，并具有一定的保健功能；在其生长过程中，豆类中的一些影响风味与营养的不利因子被去除，蛋白质与糖产生转化而更易为人体吸收。但是，豆芽在鲜销过程中容易脆断且货架期短，造成豆芽生产企业利润较低，因此有必要开发以豆芽为原料的加工产品，以提高生产效益，同时丰富市场产品。本论文以新鲜绿豆芽为原料，将其经烫漂、保脆、麦芽糊精混合液浸泡等预处理后，采用热风干燥，加工成具有一定复原率的脱水蔬菜产品；并对豆芽热风干燥后营养成分的保留、变化情况，与绿豆、新鲜豆芽等进行了比较研究；另一方面，采用高效液相色谱（HPLC）分析技术，对豆芽中的糖分变化进行了研究。主要实验结果如下：1．预处理工艺研究以绿豆芽中豆腥味（以己醛含量表示）的去除、过氧化物酶的失活为烫漂品质的主要评价指标，进行了豆芽烫漂条件的选择；以CaCl₂为保脆剂，对豆芽烫漂后的脆性恢复进行了研究；在豆芽烫漂保脆后，采用麦芽糊精、蔗糖、食盐混合液进行浸泡，以提高脱水豆芽的复水性。研究结果表明：绿豆芽在0.15％柠檬酸水溶液中，90℃烫漂2.5min过氧化物酶完全失活、己醛含量明显降低，颜色、脆度与气味综合评分较高；烫漂后在0.4％CaCl₂溶液中浸泡60min，豆芽脆性恢复较好。以复原率为考察指标，比较了麦芽糊精、蔗糖提高脱水豆芽复水性的作用，得出两者均可提高脱水豆芽得复原率，并且两者复合使用效果更好；以复水比与复原率为考查指标，通过L₉（3⁴）正交试验得出麦芽糊精混合液处理工艺：10％(W．V^-1)麦芽糊精、15％(W．V^-1)蔗糖与10％(W．V^-1)食盐混合液室温浸泡30min。2．豆芽脱水工艺研究在热风干燥工艺研究中，以复水比、复原率、白度、干燥时间四个指标按不同权重对脱水豆芽品质进行评分，进行干燥条件的选择。得出风温为60℃、装载量为0.7g／cm²时干燥效果较好；同时，对不同温度、不同装载量条件下豆芽中的水分含量变化，进行动态测定，并绘制了相应的干燥曲线。3．脱水豆芽营养成分测定与糖分研究为方便比较，在对脱水豆芽的营养成分进行测定的同时，还对绿豆、新鲜豆芽中相应的营养成分进行了测定，所测的营养成分包括：蛋白质、粗脂肪、粗纤维、灰分、Fe以及黄酮。研究结果表明脱水豆芽中各营养成分含量均较高，其中蛋白质为20.22％、粗脂肪为3.15％、粗纤维为10.82％，均高于绿豆和新鲜豆芽，其它各营养成分含量也接近或高于绿豆。利用高效液相色谱分析技术，对豆芽在麦芽糊精、蔗糖液中浸泡前后，浸泡清洗后及热风干燥后的糖分进行了研究。在对色谱图的分析中发现，纯蔗糖液中的蔗糖以及麦芽糊精中的少量麦芽糖通过浸泡可以直接进入芽体或附着在豆芽表面，在食盐的作用下，麦芽糊精中的葡萄糖和其它多糖也能渗进芽体或附着在豆芽表面。在提高脱水豆芽复水性方面，贡献最大的是蔗糖，其次是葡萄糖、麦芽糖，多糖也发挥了一定的作用。更多还原

【Abstract】 Bean sprouts are a kind of favorite vegetables. In the processing of sprouting, someingredients which affected the flavor and nutrition are eliminated. In result, proteins andsugars are transformed to the other forms which could be absorbed easily. However, beansprouts are brittle and short in shelf life. This resulted in low profits in the manufactorycorporation. It is necessary to process it into profitable products, as well as provide morekinds of food into market. Utilizing the green bean sprouts as the main material, theprocessing technology of dehydrated bean sprouts were investigated, including ofblanching, crispness-keeping, maltodextrin preparation and hot-air drying. The nutrients ofdehydrated bean sprouts were investigated compared with fresh bean sprouts and greenbean. In the end, the change of sugar ingredients in bean sprouts bean sprouts wasinvestigated by HPLC. Results were shown as bellows:1. The study on techniques of preparation to bean sproutsIn order to eliminate soybean odor and inactivate the activity of peroxidase in beansprout, green bean sprouts were blanched in hot water. After being blanched, bean sproutswere soaked in CaCl₂ solution in order to keep their crispness. Then the bean sprouts weresoaked in maltodextrin, sucrose and NaCl mixture solution to improve the rehydration ofdehydrated bean sprouts. The results indicated that the activity ofperoxidase in bean sproutwas completely lost when it was blanched in 0.15% citric acid solution for 2.5 min at 90℃and the hexanal in it was obviously decreased. The crispness of bean sprouts was keptbetter after being soaked in 0.4% CaCl₂ for 60 min. The rehydration of dried sprouts wasoptimum when soaked in the mixture solution contained 10% maltodextrin, 15% sucroseand 10% NaCl for 30 minutes. 2. The study on technique of hot-air dryingIn this part, the technique of hot-air drying was investigated. The results showed that thequality of dehydrated sprouts was optimum when the air temperature was 60℃and theweight load was 0.7g/cm², based on a comprehensive score of recovery ratio of waterabsorption, rehydration rate, whiteness and drying time. Two drying curves of green beansprouts were made under different drying temperatures and loads.3. The study on the content of some nutrients in dehydrated bean sprouts and the sugaringredients by HPLCThe nutrients of dehydrated bean sprouts, green bean and flesh bean sprouts wereinvestigated, including the content of protein, fat, fibre, mineral, Fe and flavone. Theresults indicated that the contents of protein, fat, fibre in dehydrated bean sprouts were20.22%, 3.15% and 10.82%, more than green bean and fresh bean sprouts, and the contentof other nutrients were close to green bean.The sugar ingredients in bean sprouts after being soaked, being soaked and blanched,and dehydrated bean sprouts were investigated by HPLC. The chromatograms indicatedthat sucrose and maltose could permeate into bean sprouts or stick on it in soaking. Withthe help of NaCl, glucose and some kinds of polysaccharose could permeate into beansprouts or stick on it too. Sucrose took an important part in improving the rehydration ratioof dehydrated bean sprouts, as well as glucose, maltose and polysaccharose.更多还原