【作者】 魏明英；

【导师】 邬应龙；

【作者基本信息】 四川农业大学 ， 农产品加工与贮藏工程， 2004， 硕士

【摘要】 本论文分为两大部分：第一部分对压热处理早籼米淀粉制备抗性淀粉的方法进行了研究，初步确立了制备早籼米抗性淀粉的最佳工艺条件；第二部分研究了抗性淀粉对紫红曲产糖化酶的影响。 首先研究了压热处理生产抗性淀粉时，淀粉浓度、压热冷却回生循环次数、压热时间和回生温度对抗性淀粉得率的影响。结果表明，淀粉浓度和压热冷却回生循环次数对抗性淀粉得率的影响均显著，回生温度也较大程度地影响了抗性淀粉的得率，压热时间的影响最小。压热处理制备抗性淀粉的最佳参数是：淀粉浓度为25％，压热冷却回生循环次数为11次，压热时间为60min，回生温度为80℃。基于采用直接压热处理早籼米淀粉所得制品抗性淀粉含量较低的试验事实，本研究进一步对原料淀粉进行了酶法改性预处理。结果表明，经普鲁兰酶脱支预处理获得的高直链淀粉原料样品有利于淀粉回生，脱支样品的直链淀粉含量与抗性淀粉的得率成正相关；用表观直链淀粉含量为49.30％的改性早籼米淀粉为原料，采用上述最佳参数可制备得到抗性淀粉含量达16.90％的制品。 以早籼米淀粉为对照，对直接压热处理制备到的抗性淀粉和采用脱支酶法制得的抗性淀粉进行了体外消化试验和微生物降解试验。结果表明，抗性淀粉的体外胰α-淀粉酶消化速度明显慢于早籼米淀粉；以紫红曲为接种源研究微生物降解特性时，抗性淀粉的降解速度也明显慢于早籼米淀粉。这说明该抗性淀粉具有明显的抗消化作用。 采用单因素试验和三因素二次回归通用旋转组合试验，以早籼米淀粉为碳源，对培养紫红曲产生糖化酶的液体发酵培养基进行了优化。结果表明，早籼米淀粉、NANO₃、KH₂PO₄三种培养基主要成分的浓度均对发酵液糖化酶活力产生显著影响。在此基础上，分别以上述抗性淀粉和早籼米淀粉为碳源，对比研究了紫红曲在液体发酵过程中糖化酶活力的变化规律。结果表明，对比以早籼米淀粉为碳源的培养基，紫红曲在抗性淀粉培养基中的生长速度明显加快，产糖化酶的时间明显提早且糖化酶的活力明显增大，而发酵液中的还原糖浓度明显降低。这说明以抗性淀粉为碳源时，紫红曲糖化酶的产酶过程发生了明显变化。更多还原

【Abstract】 The optimum processing parameters for preparation of Resistant starch (RS) from early indica rice starch or from the high amylose rice starch by autoclaving treatment was established . The prepared RS was also used as sole carbon source for the liquid culture of Monascus purpureus to investigate the effect of RS on production of glucoamylase.The concentration of starch slurry, repeated autoclaving/cooling cycles, autoclaving time for the autoclaving treatment were optimized by orthogonal experiment design, the experimental results showed that optimized parameters for autoclaving treatment were 25% concentration of starch slurry, 11 repeated autoclaving/cooling cycles, retrogradation temperature at 80 C, respectively.The early indica rice starch was pretreated with pullulanase for enhancement of amylose. As high as 49.30% of amylose content in rice starch was achieved by pretreated rice starch with optimum concentration of pullulanase in suitable condition. The effect of the amylose content in rice starch on RS formation by autoclaving treatment was also investigated, the RS formation from the pretreated high amylose rice starch by autoclaving treatment was significantly higher than that from raw early indica rice starch. The more content of amylose, the more yield of RS was achieved.The test for enzymatic digestion of the prepared RS by porcine pancreatic -amylase (PPA) in vitro and biodegradability by M purpureus were conducted respectively. The results showed that the digestion rate for the prepared RS by PPA in vitro was apparently slower than that for raw rice starch, and the degradation rate of the prepared RS was also much slower by M. purpureus fermentation than that of raw rice starch. The results indicated the prepared RS have been achieved both enzymatic resistance and digestion resistance in a certain degree.Selected the early indica rice starch as carbon source, A rotational composite design of quadratic regression experiments was conducted for the optimization of carborn source , inorganic nitrogen source, phosphates in the liquid culture of M. purpureus for theproduction of glucoamylase.Based on the optimized culture medium, the difference in growth and glucoamylase activity between the RS and the rice starch as sole carbon source in liquid culture was investigated comparatively. The result showed that M. purpureus growed at a quicker rate in the RS medium than that in rice starch medium, and also the glucoamylase activity in RS medium is appeared quicker and significantly higher for the whole fermentation process, but the concentration of reduction sugar is much lower in RS medium in early stage of fermentation. The result revealed that the significant difference existed in growth and glucoamylase activity between the prepared RS and the raw rice starch in liquid culture of M purpureus.更多还原