【作者】 赵瑞昌；

【导师】 姜东；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2009， 硕士

【摘要】 小麦麸皮是小麦加工的副产品,含有多种有益功能组分,同时,某些组分还有独特的理化特性。为建立小麦麸皮中主要功能组分的分离工艺,明确其独特的理化特性,本研究以小麦麸皮为原料,采用超声波、酶水解等方法对小麦麸皮中蛋白质及淀粉的分离条件进行了探讨；在此基础上,进一步分析了小麦麸皮淀粉的理化特性；同时对小麦麸皮中多种组分的综合分离进行了系统研究,初步明确了类黄酮、蛋白质、淀粉及膳食纤维的综合分离条件。主要研究结果如下：1.小麦麸皮中蛋白质的分离工艺超声波-酶法制备小麦麸皮蛋白的最佳工艺：首先将10g麸皮加入到pH 6.9(由Tris和HCl调节)的溶液中,固液比1：10,超声处理9 min,然后加入3.8 g/L的α-淀粉酶,在52.5℃下,震荡反应180 min。然后将悬浮液2000 rpm离心10 min,固液分离,上清液即是蛋白液,蛋白分离率为90.05%,调节等电点(pH 4.0),固液分离,干燥即得到麸皮蛋白,蛋白得率为71.37%。2.小麦麸皮中淀粉的分离工艺及其理化特性2.1小麦麸皮中淀粉的分离工艺中性蛋白酶法制备小麦麸皮淀粉的最佳工艺：首先将100 g小麦麸皮加入到pH7.0(由Tris和HCl调节)的溶液中,固液比1：10,然后加入3 g/L的中性蛋白酶,在45℃,震荡反应60 min,超声波处理10 min；过325目金属筛,用蒸馏水冲洗筛上物3次,2500 rpm离心淀粉浆液10 min,去掉上清液；加入100 ml酒精,振荡30 min,2500 rpm离心10 min,重复三次,干燥即得淀粉,麸皮淀粉产量为14.86 g,其中蛋白质含量为0.25%。2.2小麦麸皮淀粉的理化特性麸皮淀粉中的蛋白质含量和破损淀粉率分别为0.25%和0.93%,与面粉淀粉相比均较低,且差异达显著水平。麸皮淀粉中B型淀粉粒含量明显增多,A型淀粉粒减少,峰值前移,出现在14 um处,直径小于1.5 um的淀粉粒明显增多；小淀粉粒体积比及支/直比显著高于面粉淀粉,与之相关的膨胀势呈现相似趋势。麸皮淀粉的糊化温度显著高于面粉淀粉,但糊化值明显低于面粉淀粉。X射线衍射图谱表明,与面粉淀粉晶体结构的A型特征不同,麸皮淀粉的尖峰不明显,且相对结晶度显著小于面粉淀粉。3.小麦麸皮中类黄酮、蛋白质、淀粉及膳食纤维的综合分离小麦麸皮中类黄酮、蛋白质、淀粉及膳食纤维全面制备的过程中,类黄酮得率为2.3‰；碱法制备小麦麸皮蛋白的最佳工艺条件：pH8.5,时间75min,温度45℃,固液比1：15,提取率为54.8%,酸沉条件：pH4.0,得率为43.71%；中性蛋白酶法分解小麦麸皮蛋白的最佳工艺条件：中性蛋白酶浓度3.1g/L,反应温度44.5℃,反应时间75min,在此条件下的蛋白得率为0.648±0.04%；通过筛分法进一步分离制备出淀粉和膳食纤维,得率分别为12.64%和38.27%,其中淀粉中蛋白质含量为0.21%。更多还原

【Abstract】 Wheat bran, main byproduct of wheat flour milling, contains various types of the function compound. Some compound had a unique physical chemistry property. A study was conducted to establish the technique of main function compound extracted from wheat bran, characterize the physical chemistry property of some compound. Primal function compound was extracted from wheat bran by enzyme and ultrasonic treatments. Based on these studies, physical chemistry property of wheat bran starch were further characterized; the comprehensive processing of flavonoid, protein, starch, diet fiber from wheat bran was analyzed systematically, condition of processing were demonstrated elementarily. The main results were summarized as follows:1. Craft of protein production from wheat branWheat bran (10 g, as is) was mixed with deionizer water (100 ml) in a 500 ml beaker, the slurry was conduct for 9 min with ultrasonic sound, then the temperature was maintained at 52.5℃with a circulator, and the pH of the slurry adjusted to 6.9 with Tris and HCl. a-amylase at3.8 g/L was added to the slurry and reacted for180 min with constant stirring. The slurry was centrifuged at 2000 rpm for 10 min. The top layer was carefully removed and then adjusts isoelectric point (pH 4.0), dries. Under these conditions, the experimental yield was 90.05%, which is well matched with the predictive yield.2. craft and property of starch production from wheat bran2.1 Craft of starch production from wheat branWheat bran (100 g, as is) was mixed with deionizer water (1000 ml) in a 5000 ml container, the temperature was maintained at 45℃with a circulator, and the pH of the slurry adjusted to 7.0 with Tris and HCl. Neutral protease at3.0 g/L was added to the slurry and reacted for 60 min with constant stirring, the slurry was conduct for 9 min with ultrasonic sound, After the protease digestion, The slurry was passed though a 325 screen and washed with deionizer water three times. Then the flour slurry was centrifuged at 2500g for 10 min. The solid was dryings to obtain starch. Under this condition, starch production is 14.86g, while protein content is 0.25%.2.2 Property of starch production from wheat bran Content of protein content and damaged starch in wheat bran starch was 0.25%,0.93%, separately, lower than that in starch isolated from flour. Bran starch contained lower A-type starch content, while B-type starch and C-type starch (d<1.5 um) was increased obviously, peak value is at 14 um. Compared with the starch isolated from flour, bran starch contained lower amylose content, and the pasting value was lower, the degree of crystallinity was smaller, while the swelling power was higher. and the pasting value was lower, the degree of crystallinity was smaller, while the swelling power was higher. X-ray chromatogram showed: bran starch has not A-type chromatogram, but flour starch has. which is different from flour starch.3. Comprehensive processing of flavonoid, protein, starch and diet fiber from wheat branThe results showed that the optimal conditions for extraction of wheat bran protein by alkali-processing were:pH 8.5, extracting time 75min, and extracting temperature 45℃, Solid/liquid 1:15, and extracting rate are 54.8%, and pH value of acid-depositing was 4.0, with yield rate 43.71%. The optimal conditions for hydroxylation of wheat germ protein by neutral protease were:extracting time 75min, extracting temperature 44.5℃, and concentration of neutral protease 3.1g/L, with protein content is 0.648±0.04%, which is well matched with the predictive yield. Flavonoid ratio, starch and diet fiber content is 2.3‰,12.64% and 38.27%, separately.更多还原