【作者】 邵瑜；

【导师】 张燕萍；

【作者基本信息】 江南大学 ， 制糖工程， 2007， 硕士

【摘要】 本论文主要研究了以玉米淀粉为原料,添加氧化玉米淀粉、交联玉米淀粉、氧化-交联玉米淀粉及交联-氧化玉米淀粉后制备玉米淀粉牙签的工艺及性质,同时研究了淀粉性质对玉米淀粉牙签品质的影响。首先对变性淀粉的透明度、流变性、直链淀粉含量等性质进行了分析,发现:氧化玉米淀粉、交联-氧化玉米淀粉的淀粉糊透明度随羧基质量分数的增大而增加,交联玉米淀粉、氧化-交联玉米淀粉的淀粉糊透明度随交联度的增大几乎不变。氧化玉米淀粉、交联玉米淀粉、氧化-交联玉米淀粉及交联-氧化玉米淀粉糊的粘度均随温度的降低而上升,随剪切速率的变大而下降,属于非牛顿流体。对于氧化玉米淀粉和交联-氧化玉米淀粉而言,直链淀粉含量随羧基质量分数增大先下降后上升。对于交联玉米淀粉和氧化-交联玉米淀粉而言,随着交联度的增大,直链淀粉含量几乎不变。研究了玉米淀粉牙签的制备工艺。以形变率达100%时的剪切应力为指标,研究了添加不同变性淀粉、干燥方式、水的添加量、增塑剂的添加量对玉米淀粉牙签硬度的影响,确定了制备玉米淀粉牙签的较优工艺条件:在玉米原淀粉中添加20%的氧化-交联玉米淀粉(羧基质量分数为0.2125%、溶胀度为178.4%,以玉米淀粉干基计),甘油10mL /100g玉米淀粉(干基,d.b),调节面团水分质量分数为47.37%(其中50%用于糊化,以玉米淀粉干基计),挤压成型后置于沸水中捞出,-4～0℃冷藏4h后45℃烘箱干燥,此时牙签硬度为1.680×105 g/mm2。通过对玉米淀粉牙签性质的研究发现:添加甘油、氧化玉米淀粉、氧化-交联玉米淀粉和交联-氧化玉米淀粉能提高玉米淀粉牙签的透明度。添加变性淀粉的玉米淀粉牙签都具有较好的弹性,硬度与弹性并无相关性。在水中浸泡2min以内,玉米淀粉牙签的硬度几乎不变,浸泡5～30min,不同种类的玉米淀粉牙签性质不同,添加氧化玉米淀粉或交联-氧化玉米淀粉的玉米淀粉牙签硬度下降较快,添加交联玉米淀粉或氧化-交联玉米淀粉的玉米淀粉牙签硬度下降很少。添加氧化玉米淀粉或氧化-交联玉米淀粉的玉米淀粉牙签的降解性能优于添加交联玉米淀粉或交联-氧化淀粉的玉米淀粉牙签。在较优工艺下制得的添加氧化-交联玉米淀粉的淀粉牙签透明度为6.7%,剪切形变为62.4%,软化时间长,断裂时间为12.92min,各项指标均优于其它种类的玉米淀粉牙签。通过红外谱图分析显示:添加氧化-交联玉米淀粉的玉米淀粉牙签在995cm-1的吸收高于玉米原淀粉牙签,判断该吸收峰的增强主要是由于氧化-交联后淀粉分子内氢键加强;1022cm-1处吸收峰的增强表明添加氧化-交联玉米淀粉的玉米淀粉牙签结构的无序态增强;1047cm-1几乎没有吸收峰,说明添加氧化-交联玉米淀粉的玉米淀粉牙签结晶结构几乎消失。更多还原

【Abstract】 The preparation and properties of corn starch toothpick adding oxidized corn starch, cross-linked corn starch, oxidized-crosslinked corn starch and crosslinked-oxidized corn starch were studied.The properties of modified corn starch were studied. The gel’s transparency of oxidized corn starch and crosslinked-oxidized corn starch increased with the amount of carboxyl content. The gel’s viscosity of oxidized corn starch, cross-linked corn starch, oxidized-crosslinked corn starch and crosslinked-oxidized corn starch increased with temperature decrease. The modified starch gel’s belonged to non-Newtonian fluid, were shear-thinning. For oxidized corn starch and crosslinked-oxidized corn starch, the amylose content first decreased and then increased as the carboxyl content increased. For cross-linked corn starch and oxidized-crosslinked corn starch, the amylose content did not change with the cross-linking degree.The preparation of corn starch toothpick was studied. The factors which had influence on the shear stress of corn starch toothpick which was prepared by adding different modified starch were also studied, such as drying method, colding time, the moisture of paste, the kind and addition of plasticizer. It has been found that the shear stress of corn starch toothpick got maximum 1.680×105g/mm2 under the following optimal conditions: making dough by mixing the corn starch, 20% of oxidized-crosslinked corn starch(carboxyl content of 0.2125%, cross-linking degree of 178.4%, for gelatinization, corn starch dry basis), every 100g corn starch(corn starch dry basis) with 10mL glycerine and regulating water for 47.37%(of which 50.00% for gelatinization, corn starch dry basis), extruding, forming, oven drying at 45℃after colding for 4h at -4～0℃.The properties of corn starch toothpick were studied. The transparency of corn starch toothpick increased as glycertine、oxidized corn starch、oxidized-crosslinked corn starch and crosslinked-oxidized corn starch were added. The elasticity was improved as modified corn starches were added. There was no correlation between shear stress and elasticity. The shear stress of corn starch toothpick dipped in water for 5~30minutes which was made by adding oxidized corn starch or crosslinked-oxidized corn starch decreased faster than adding cross-linked corn starch or oxidized-crosslinked corn starch. The degradability of corn starch toothpick which was made by adding oxidized corn starch or oxidized-crosslinked corn starch was better than adding cross-linked corn starch or crosslinked-oxidized corn starch. Under optimal conditions the transparencies, shear deformation, breaking time of corn starch toothpick by adding oxidized-crosslinked corn starch were: 6.7%, 0.624, 12.92min respectively.Corn starch toothpick was analyzed by FTIR for structure investigation. The band at 995cm-1 and 1022cm-1 increased, the 1047cm-1 decreased, compared corn starch toothpick by adding oxidized-crosslinked corn starch to native corn starch toothpick. It was suggested that the increasing band of 995cm-1 could be associated with strengthen of intermolecular hydrogen bond, the increasing band of 1022cm-1 could be associated with the increase of amorphous, the decreasing band of 1047cm-1 could be assumed the loss of crystalline.更多还原