- 无标题文档
国产毛片农村妇女系列bd版,日本wwwhdsex69,精品国产品国语在线不卡,久久影院 网站地图
查看论文信息

论文题名(中文):

 好食脉孢菌发酵醋糟瘤胃降解特性及产类胡萝卜素抗氧化活性的研究    

作者:

 张林    

学号:

 S20162053    

保密级别:

 秘密    

论文语种:

 chi    

学科代码:

 071010    

学科名称:

 理学 - 生物学 - 生物化学与分子生物学    

学生类型:

 硕士    

学位:

 理学硕士    

学校:

 山西农业大学    

院系:

 动物科技学院    

专业:

 生物化学与分子生物学    

研究方向:

 营养生物化学与分子生物学    

第一导师姓名:

 陈书明    

第一导师学校:

 山西农业大学    

论文完成日期:

 2019-06-15    

论文答辩日期:

 2019-05-29    

论文题名(外文):

 Study on the Ruminal Degradation Characteristics of Fermented Vinegar Residues by N. sitophila and the Antioxidant Activity of Carotenoids from the Fermentation    

关键词(中文):

 好食脉孢菌 发酵 醋糟 瘤胃降解率 类胡萝卜素 抗氧化    

关键词(外文):

 N.sitophila fermentation vinegar residues ruminal degradability carotenoids antioxidant    

论文文摘(中文):

  为使排放量大、营养价值低的醋糟转化为高营养功能饲料,首先进行了好食脉孢菌发酵醋糟试验,并对发酵醋糟体外瘤胃及绵羊瘤胃降解特性进行了研究。然后,对上述发酵产类胡萝卜素工艺、提取方法及抗氧化活性进行了系列研究。
1. 与未发酵醋糟组相比,好食脉孢菌发酵醋糟组体外瘤胃降解特性如下:两组累计产气量均表现为GP24h48h72h(P<0.05),发酵醋糟组GP24h、GP48h、GP72h和ME均显著升高(P<0.05),CH4浓度、DMD、NDFD和ADFD均显著降低(P<0.05),VFA、NH3-N、蛋白氮、尿素氮和总氮含量差异均不显著(P>0.05)。
2. 利用尼龙袋法评定了醋糟发酵前后营养价值的变化,结果显示,与未发酵醋糟组相比,好食脉孢菌发酵醋糟组DM有效降解率显著升高(P<0.05),CP和NDF的有效降解率显著降低(P<0.05),而ADF有效降解率差异不显著(P>0.05)。
3.用响应面Box-Behnken设计法,优化了好食脉孢菌发酵醋糟产类胡萝卜素的工艺条件,并研究了几种发酵助剂对好食脉孢菌类胡萝卜素产量的影响。结果显示,最优发酵条件为:接种量8%(100 g醋糟培养基干基中添加8 ml好食脉孢菌种子液,种子液浓度为1.4×106 CFU/ml),含水量58%,29℃发酵85 h,在此条件下类胡萝卜素产量达68.05 mg/kg。在好食脉孢菌发酵醋糟培养基中添加一定量番茄汁、桔子皮、金属离子(Mg2+、Ca2+、Zn+、Fe2+、K+)和维生素(VB1、VB2、VC)等发酵助剂,均可提高类胡萝卜素产量,其中,桔子皮的作用最显著,在1 kg醋糟培养基中添加桔子皮4.2 mg,类胡萝卜素产量最大,达119.85 mg/kg,是对照组(67.01 mg/kg)的1.79倍。
4.用单因素试验对好食脉孢菌孢子破壁方法及类胡萝卜素抽提溶剂进行了筛选,并在此基础上,以乳酸浓度、乳酸用量、振荡时间及沸水浴时间4个主要因素为自变量,以类胡萝卜素提取量为因变量,运用Box-Behnken分析法,对好食脉孢菌中类胡萝卜素提取工艺进行了优化。结果显示:乳酸热破壁法是好食脉孢菌破壁最适宜方法,体积比2:1的乙酸乙酯与无水乙醇混合液是最佳的类胡萝卜素抽提溶剂。好食脉孢菌破壁工艺参数优化组合为乳酸浓度2.8 mol/L,乳酸用量14 ml/g,振荡时间20 min,沸水浴时间8 min;在此条件下,类胡萝卜素提取量为793.75 mg/kg。
5.体外抗氧化试验结果显示,好食脉孢菌发酵醋糟产类胡萝卜素抗氧化能力与其浓度(5~200 μg/ml)呈正相关,其对DPPH、超氧阴离子和羟基自由基的清除能力显著高于同浓度β-胡萝卜素、VC和VE(P<0.05)。此外,该发酵所产类胡萝卜素还具有抑制脂类物质氧化及金属离子螯合能力。
上述试验结果表明,好食脉孢菌发酵不仅可提高醋糟的营养价值,而且可产生具有较强抗氧化活性的类胡萝卜素,本研究为研发醋糟类胡萝卜素功能饲料奠定了基础。
 

文摘(外文):

~In order to convert the vinegar residues with large emissions and low nutritional value into high-nutrition functional feeds, a fermentation experiment of vinegar residues by N.sitophila was conducted, and the degradation characteristics of fermented vinegar residues in sheep rumen were studied in both vitro and vivo experiments. Then, a series of studies were conducted regarding the fermenting production process, extraction methods and antioxidant activities of carotenoids.
1. Compared with those of the unfermented vinegar residues, the rumen degradation characteristics of the fermented vinegar residues were as follows: the cumulative gas production of both groups showed GP24h48h72h (P<0.05), while the fermented vinegar residues group showed significant increase in GP24h, GP48h, GP72h and ME (P<0.05), and significant decrease in CH4 concentration, DMD, NDFD and ADFD (P<0.05). There were no significant differences in VFA, NH3-Nitrogen, protein nitrogen, urea nitrogen and total nitrogen (P>0.05).
2. Nylon bag technique was used to evaluate the nutritional value of vinegar residues before and after fermentation. The results showed that the effective degradability of DM in fermented vinegar residues was increased significantly from the unfermented ones(P<0.05), while the effective degradability of CP and NDF was decreased significantly (P<0.05), and the effective degradability of ADF showed no significant difference (P>0.05).
3.The Box-Behnken Design tests were used to optimize the technological conditions of vinegar residues fermented by N. sitophila, and the effects of several fermentation promoting factors on the carotenoids yield of N. sitophila were studied. The results showed that the optimal fermentation conditions were: inoculation amount at 8% (100 g of vinegar residues solid medium was added with 8 ml of spore suspension of N. sitophila with the spore suspension of concentration at 1.4×106 CFU/ml), moisture content at 58%, and fermentation time at 85 h, under which the carotenoids yield could reach 68.03 mg/kg. The production of carotenoids was increased by adding tomato juice, orange peel, metal ions (Mg2+、Ca2+、Zn2+、Fe2+、K+) and vitamins (VB1、VB2、VC) in the medium. The orange peel showed the most significant effect among these fermentation promotors. When 4.2 mg orange peel was added to 1 kg vinegar residues medium, the carotenoids production reached 119.85 mg/kg, which was more than 1.79 times as large as the production of the control group.
4. The methods of breaking the cell wall of N. sitophila spores and the extracting solvents for carotenoids were both screened by single factor tests. Based on the results of the single factor tests, the Box-Behnken design (BBD) was used to optimize the extraction process of carotenoids in N. sitophila, with lactic acid concentration, lactic acid dosage, oscillating time and boiling water bath time as independent variables and the extraction yield of carotenoids as dependent variable. The results showed that the method of lactic acid-heat assisted was the best to break the cell wall, and the mixed solvent of ethyl acetate and absolute ethanol (2:1) was the most suitable solvent for the extraction of carotenoids. The optimum combination of the parameters of the broken cell wall of the N. sitophila was: lactic acid concentration at 2.8 mol/L, lactic acid dosage at 14 ml/g, oscillating time at 20 min, and boiling water bath time at 8 min. Using the optimized process, the extraction yield of carotenoids was 793.75 mg/kg.
5. The results of in vitro antioxidant test of carotenoids produced by N. sitophila showed that the antioxidant activity of carotenoids was positively correlated with the concentration of extract (5~200 μg/ml). Its scavenging ability against DPPH, superoxide radicals and hydroxyl radicals was significantly stronger than the β-carotene, VC and VE at the same concentration (P<0.05). In addition, carotenoids from N. sitophila fermentation also showed a certain inhibition ability on the oxidation of lipids and metal ion chelating.
The above results indicated that the fermentation of N. sitophila not only improves the nutritional value of vinegar residues, but also produces carotenoids with strong antioxidant activity, which lay a foundation for the development of functional feeds of carotenoids from vinegar residues.
 

中图分类号:

 Q815    

馆藏号:

 Y9751    

开放日期:

 2021-06-20    

无标题文档