超微绿茶粉酸奶的制造工艺研究

【作者】 支明玉；

【导师】 钱俊青；

【作者基本信息】 浙江工业大学 ， 制药工程， 2009， 硕士

【摘要】 酸奶是一种药食两用的食品,有良好的药理作用和营养功能。超微绿茶粉能最大限度地保持茶叶原有的营养成分、药理成分和原料的天然本色,可广泛用于加工各种茶叶食品和添加于各类食品中,以强化其营养保健功效,并赋予各类食品的天然鲜绿色泽和特有的茶叶风味。将超微茶粉作为一种添加剂加入到酸奶中,制作成超微茶粉酸奶,既能保持酸奶原有的营养价值和保健作用,同时又具有茶叶的风味。本论文通过对超微绿茶粉进行显微观察、显微测量以及对其主要化学成分的测定,在研究其理化性质的基础上,寻求一条最佳的超微绿茶粉酸奶生产工艺。研究表明:经过超微粉碎的茶叶的茶多酚、氨基酸、咖啡碱等主要内含成分没有发生明显变化。本文研究超微绿茶粉酸奶的加工工艺,研究杀菌温度和时间对乳酸菌活菌数及酸奶感官品质的影响,确定了杀菌工艺为95℃,5分钟;研究茶粉抑菌阈值,确定了茶粉的最大用量1%;研究鲜奶添加量对酸奶活菌数和凝固时间的影响,得出鲜奶的适宜添加量为85%;研究影响酸奶工艺的主要因子,从正交试验结果中可以看出,A₂B₂C₁D₁为最佳组合,其中A为超微茶粉的添加量,B为砂糖的添加量,C为稳定剂的添加量,D为菌种添加量。对该组合进行酸奶制作,所得酸奶的活菌数为3.10×10⁹个/ml。从试验结果还可看出,在制作超微茶粉酸奶的过程中,砂糖加入量对产品影响最大,其次依次为菌种接种量＞稳定剂添加量＞茶粉添加量。结合正交试验的结果,同时考虑到酸奶的风味及感官品质,试验最后所得结论为:超微绿茶粉的添加量为0.50%,砂糖添加量为7%,变性淀粉的添加量为0.10%,菌种接种量为4%,该条件下进行酸奶制作,所得酸奶的活菌数为3.82×10⁹个/ml。本试验还研究了贮藏期间酸奶的酸度、pH值及乳酸菌的变化,酸奶在贮藏初期酸度略有升高,随后又成下降趋势,没有产生过酸化的现象,贮藏期间超微绿茶粉酸奶的酸度变化与普通酸奶一致。更多还原

【Abstract】 yoghurt is an edible and medical food, which has good pharmacological effects and nutritional function. Keeping its nutritional, pharmic contentand natural green color in the large extent, ultramicro tea powder is widely used asadditive to all kinds of food ,which not only strengthen food’s nutrition but also make the food have the nature color and tea flavor etc. The yoghurt added the tea powdereither have the acidophilus milk nutrition or possess the tea flavor at the same time.Microscopic observation and microdetermination were applied in tea powder. Thechemical components were also invetisgated .On the basis of this work, we aimed to find an appropriate manufacturing technology of adding ultrafine tea powder to theyoghurt.The results indicated that the content of tea component such as teapolyphenol, amino acid ,caffeine etc have little change by attritioning.The technology of tea powder yoghurt was studied in this paper. The research about the effect of sterilization temperature and time on Quantity of Lactic Bacteria and sense Evaluation Results of yoghurt determines the sterilization process which is in 95°C for 5 minutes.The thresholdvalue of antibacterial was invetisgated. The result showed that the maximum dosage oftea powder was 1%. Effect on the amount of lactic acid bacteria and the coagulationtime were studied. The result showed that the optimal additive quantity of milk was 85%. The major factor of influence on the production technology were also researched. The orthogonal experiments result indicated that the A₁B₂C₁D₁ was the optimal combination. Based on this combination, the number of lactic acid bacterial were 3.10×10⁹ mL^-1. With a view tothe yoghurt flavor and sensory quality, The conclusion of the research is: The affixing amount of ultramicro green tea power, granulated sugar, and denaturated starch is 0.50%, 7% and 0.10% respectively, and the strain inoculum concentration is 4 %. Based on this combination, the number of lactic acid bacterial were 3.82×10⁹ mL^-1.The titratable acidity ,the pH and the variety of Lactobacillus amount were also studied. Thacidity value of tea powder yoghurt ascended lightly in early store period, but itdecreases in anaphase. The yoghurt did not appear superacidulation phenomena during storage.更多还原