Study On The Sake Made From Rice And Lotus Seeds

With the enhancement of people’s living standards and people’s health awareness, people pay more attention to health care function of wine. Rice and lotus seeds are rich in resource in china. Sake can prevent cancer, heart disease, hypertension, diabetes, amnesia and osteoporosis, etc. So it has a broad development space for brewing rice-lotus sake which has lighter taste and local characteristics. This thesis study the raw material of wine and bacteria, combined with a single factor and orthogonal experiments, detected the basic physical and chemical indicators of fermented wine in order to optimize the fermentation process of rice-lotus seeds sake, study the clarification and sterilization process of wine, analyzed the quality of the sake at last, Flavor substances of aged wine were detected by GC-MS, sensory evaluation, physical and chemical detection and microbiological detection was carried out when the sake finished, so it can provide a certain theoretical basis for brewing rice-lotus seeds sake. The main results were as follows: 1. In the brewing process, ingredients of raw materials and processing methods of raw materials were closely related to the quality of wine. Therefore, the detection of physical and chemical composition of rice and lotus seeds and the study of ingredients after soaking and cooking may provide the scientific basis for developing the rice and lotus seeds fermentation products. The experimental results showed that water absorption increased and the pH of the impregnating solution decreased in the soaking process of raw materials. Crude protein, crude fat, total sugar and reducing sugar in raw materials showed a downward trend in the soaking process. As the soaking temperature increased, the loss of nutrients is more powerful. In order to achieve the effect of soaking without making excessive loss of nutrients, experiment may select soaking temperature at20℃for one day. The content of raw protein decreased slightly, the content of crude fat increased and the content of starch has a small amount of increased trends after cooking. The experiment can use ratio of material to water of1:1.4when cooked raw materials, it can obtain a higher alcohol content, more appropriate sugar content and acidity.2. Yeast plays a very important role in wine brewing process. Temperature, pH is an important environmental factors that affect microbial growth and reproduction. The study of yeast growth characteristics discovered that the optimum growth temperature of yeast in the medium between25-30℃, the optimum growth pH of yeast in the medium between5-6. The yeast has a good tolerance for sugar, salt and alcohol. With the increase of sugar, salt and alcohol, the growth of yeast reduced. Amylase and glucoamylase in Koji affect the decomposition of the starch compositions. They have a significant impact on the entire brewing process of the wine. The moisture of Clinker, the incubation temperature of Aspergillus oryzae, the addition of Aspergillus oryzae will affect the enzyme activity of Koji. The experiment showed that the suitable water content of clinker between40-50%, suitable temperature of Aspergillus oryzae between30-35℃, optimal addition of Aspergillus oryzae is1%.3. The experiment mainly research brewing process of sake, fermentation temperature, yeast addition, Koji addition, material to water ratio, initial pH as single factor were researched in the fermentation process. According to the results of single factor experiments, the orthogonal test was designed, the optimum conditions for brewing rice wine were as follows:fermentation temperature:20℃, yeast addition:5%, Koji addition:0.2%, material to water ratio:1:1.5, initial pH:5.0. The optimum conditions for brewing lotus wine were as follows: fermentation temperature:21℃, yeast addition:5%, Koji addition:0.3%, material to water ratio:1:1.8, initial pH:5.0. In order to play the of the health functions of the lotus effectively and cost savings as much as possible, Combined with alcohol factors, lotus seeds wine and rice wine can take the blending ratio of1:7. Alcohol, production costs, and health functions of lotus as considerations, lotus seeds and rice can take the blending ratio of1:6. The optimum conditions of brewing rice-lotus wine were as follows:fermentation temperature:20℃, yeast addition:6%, Koji addition:0.3%, material to water ratio:1:1.8, initial pH:5.0. The experimental results may provide a reference for industrial brewing rice-lotus sake and promote the rational use of resources.4. Gelatin, chitosan, PVPP, egg white, papain, activated carbon as the clarifying agent is used to clarify original wine. The experimental results showed that the clarification effect of gelatin-chitosan is best, and its clarification rate reached95.2%. In addition, the clarification effect of chitosan, gelatin and PVPP used separately is quite good. The optimum clarification process of Gelatin-chitosan were as follows: gelatin addition:0.15%, chitosan addition:0.01%, clarification temperature:30℃, clarification time:9h. Gelatin-chitosan association has a synergistic effect, and the samples treated by gelatin-chitosan association have better hot and cold stability. Experiment select heat sterilization, UV sterilization and ozone sterilization. The best sterilization effect is UV sterilization, followed by ozone sterilization, their sterilization rate can reach more than93%, sterilization effect of heat sterilization is far from satisfactory. The physical and chemical indicators of sake have not changed significantly and still maintained original flavor of the sake after clarification and sterilization process.5. The44aroma components in aged wine had been detected by GC-MS. The experiment measured the relative content of the flavor substances:ester compounds>alcohols>acids. They were made up of Diisobuty lphthalate,Diethylsuccinate,EthylAcetate,1,3-Propanediol-1,3-diacetate,Ethy lbutyrate,Butyrolactone,1-Nonen-4-ol,3-Ethoxy-1-propano1,BenzylAlcohol,Hexanol,1-Pentanol,Hexanoicacid,2-methylpropioricaci d,3-HydroxybutyricAcid,3-Hydroxy-2-butanone,2-methylbutene,Octade cane,n-Hexanal,etc.The important flavor compounds of sake is mainly esters, alcohols and acids, In addition, other compounds such as aldehydes, ketones, heterocyclic compounds, alkenes, alkanes also Constitute the aroma ingredients of sake.