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1.
双波长比色法测定马铃薯直链/支链淀粉含量   总被引:3,自引:0,他引:3  
将新鲜马铃薯中的淀粉提出后,采用双波长比色法测定了直链/支链淀粉含量。淀粉经I2-KI溶液染色,直链淀粉呈蓝色,支链淀粉呈紫色。535和570 nm用于直链淀粉含量测定,555和760 nm用于支链淀粉含量测定。结果表明,样品溶解是检测的关键,淀粉与碘试剂的反应时间会对测定结果造成一定影响。同时通过本方法的检测,新大坪品种马铃薯的直链淀粉含量为21.20%,支链淀粉含量为78.80%。  相似文献   

2.
以粉葛为原料,对粉葛中直链淀粉和支链淀粉的分离工艺进行了研究。根据直链和支链淀粉的理化特性及结构的不同,采用正丁醇-异戊醇配合物沉淀法对粉葛直链和支链淀粉进行粗分离,再经正丁醇重结晶得到较纯的直链与支链淀粉,讨论了分离前对淀粉进行预处理、纯化次数、分离过程中离心时间对分离效果的影响。通过对淀粉-碘复合物光吸收特性分析和蓝值比较,表征分离得到的直链与支链淀粉的纯度。结果表明:直链淀粉纯化5次、支链淀粉纯化6次、分离前经过预处理、支链淀粉纯化时离心时间和速度为30min,5 000r/min的条件下,光谱分析测得的最大吸收波长和蓝值都落在直链淀粉与支链淀粉文献报道结果的相应数值范围内,表明此时分离效果最佳,正丁醇结晶法分离的直链和支链淀粉纯度较高。  相似文献   

3.
玉米淀粉组分的分离及特性   总被引:1,自引:0,他引:1  
李德海  马莺 《食品工业科技》2011,(5):116-119,122
以玉米淀粉为原料,常温下利用稀碱溶液对淀粉进行快速分散分离玉米直链淀粉和支链淀粉。以玉米直链淀粉和支链淀粉的收率和蓝值为评价指标,通过正交实验确定最佳分离工艺,结果表明:分离玉米直链淀粉的最佳工艺为NaOH浓度0.35~0.45mol/L,NaCl浓度为5%,离心机的转速为7000~8000r/min;分离玉米支链淀粉的最佳工艺为NaOH浓度0.35~0.40mol/L,NaCl浓度为4%,离心机的转速为7000~8000r/min。并通过蓝值、黏度及黏度稳定性、凝胶渗透色谱方法对其性质和纯度进行了初步分析。  相似文献   

4.
本文通过测定糯小麦淀粉、糯玉米淀粉和谷物淀粉与碘结合后的吸收光谱,发现直链淀粉分子和支链淀粉分子在与碘分子形成包合物时存在结合速率(结合顺序)的差异.即直链淀粉首先与碘结合,只有当碘液的添加量足够大,与直链淀粉充分结合后仍剩余有一定量时,支链淀粉才与碘结合.同时,本文测定了几种糯小麦淀粉的直链淀粉分子含量,发现不同文献测量值之间的差异是计算基准不同造成的.  相似文献   

5.
本文研究了稻米淀粉不同级分的理化特性及稻米类型对各级分理化特性的影响。结果表明 :稻米淀粉级分的理化特性有较大差异 ,稻米类型对各级分理化特性有影响。直链淀粉的碘结合力为 19.99~2 0 .31mgI2 /g淀粉 ,支链淀粉为 0 .0 6~ 0 .0 95mgI2 /g淀粉 。直链淀粉的碘兰值为 0 .2 0~ 0 .2 5OD/0 .1g淀粉 ,以籼稻直链淀粉的碘兰值较大 ;支链淀粉碘兰值为 0 .0 3~ 0 .10OD/0 .1g淀粉 。直链淀粉的特性粘度为 5 0~ 15 0mL/g ,以粳稻较大 ;支链淀粉的特性粘度为 5 0 0~ 95 0mL/g ,以糯稻最大 ,籼稻最小。直链淀粉与碘复合物的可见光最大吸收波长为 6 0 0~ 6 2 0nm ,支链淀粉为 5 2 0~ 5 40nm ,品种差异较小。分离纯化后直链淀粉的结晶度为 2 3%~ 2 5 % ,支链淀粉则无晶体结构 ,结晶度的品种差异较小。稻米支链淀粉的分子量为 4 7× 10 6 (籼稻 )~ 2 35× 10 6 (糯稻 ) ,直链淀粉的分子量为 0 .4 4× 10 6 (籼稻 )~ 1.6 2× 10 6 (粳稻 )。  相似文献   

6.
目的 研究6种不同种类直支链淀粉相互混合对其回生的影响。方法 将玉米淀粉、甘薯淀粉、木薯淀粉、马铃薯淀粉、糯米淀粉、小麦淀粉等6种不同种类直支链淀粉分离出来, 然后两两混合, 研究不同直支链混合对其回生率的影响。 结果 马铃薯支链淀粉与甘薯支链淀粉以2:8(m:m)混合回生率最低, 为60.0%, 玉米支链淀粉与木薯支链淀粉以8:2(m:m)混合回生率最低为52.6%, 小麦支链淀粉与糯米支链淀粉以8:2(m:m)混合回生率最低为51.2%, 甘薯支链淀粉与小麦支链淀粉以1:1(m:m)混合回生率最低为53.7%。木薯支链淀粉与小麦直链淀粉以1:1(m:m)混合时所得淀粉回生率最大, 达到了92.0%, 混合淀粉回生后X射线晶型为B型。结论 不同种类直支链淀粉混合对其回生率影响很大, 食品加工中尽量不要混合使用木薯支链淀粉与小麦直链淀粉。  相似文献   

7.
双波长法测定小麦及小麦芽中直链、支链淀粉含量   总被引:10,自引:2,他引:8  
采用双波长法对15种小麦品种的直、支链淀粉的含量进行了测定,并选择淀粉含量及支链/直链比有代表性的6个品种进行制麦试验,研究了小麦制麦芽期间淀粉含量的变化,以期探讨一种简便快捷的测定小麦及麦芽中淀粉含量的方法,并为筛选适合制麦芽小麦品种提供依据.根据碘-直链淀粉和碘-支链淀粉复合物的吸收光谱,选择直链淀粉的测定波长为631 nm和480 nm,支链淀粉的测定波长为554 nm和754 nm,依据回归方程可求出直链和支链淀粉的含量.直链淀粉的浓度在0~30μ/mL,支链淀粉在0~110μg/mL范围内符合比耳定律.制麦前后总淀粉降解程度与原小麦中支链/直链淀粉存在正相关性(P<0.1),相关系数r=0.802.  相似文献   

8.
研究直链淀粉和支链淀粉比例对浆料性能的影响。以高直链玉米淀粉和蜡质(支链)玉米淀粉为原料,运用光学显微镜、差示扫描量热仪研究了高直链玉米淀粉糊化所需要的条件;测试比较了不同比例的直链淀粉和支链淀粉混合浆液黏度、浆液黏附性能、浆膜性能等指标。结果表明:高直链玉米淀粉在130℃下糊化15min才能完全糊化;随着直链淀粉含量的增加,浆液的黏度下降,黏度热稳定性提高;浆膜的断裂强度、断裂伸长、耐屈曲性及磨耗增加,但对棉、涤棉粗纱的黏附力降低。认为浆料中直链淀粉和支链淀粉比例对其上浆性能有明显影响。  相似文献   

9.
以市售新鲜怀山药为原料通过石灰水浸泡法制备山药粉,并通过正丁醇反复结晶法分离纯化直链淀粉与支链淀粉。利用碘做显色剂,使用毛细管电泳法测定山药淀粉中直链淀粉与支链淀粉的含量以及比率,本文分别对柠檬酸-磷酸盐缓冲液以及醋酸-醋酸盐缓冲液等不同缓冲液作为流动相进行了对比,实验发现醋酸-醋酸盐缓冲液对于分离测定直链淀粉与支链淀粉的效果较好。随后分析了不同p H条件下的醋酸-醋酸盐缓冲液进行的分离效果进行了比较,并测定其迁移率,当p H 4.8时分离效果最佳且其迁移率达到15.4。利用最佳条件使用纯的马铃薯直链淀粉与支链淀粉标准品,得出支链淀粉的保留时间约为1.8 min,而直链淀粉的保留时间约为2.9 min,对怀山药淀粉进行分析,从而得出怀山药中直链淀粉含量为19.49%。利用重复性试验以及回收率试验该方法的准确性与精确度能达到很好的效果。  相似文献   

10.
双波长法测定木薯淀粉中直链和支链淀粉的含量   总被引:1,自引:0,他引:1  
目的:分离纯化木薯淀粉中的直链和支链淀粉,建立同时测定木薯淀粉中直链与支链淀粉含量的双波长法。方法:采用正丁醇结晶法分离纯化直链和支链淀粉,蓝值比较法表征直链与支链淀粉的纯度;根据双波长法原理,分别在测定波长624、538nm,参比波长440、750nm处测定木薯淀粉中直链与支链淀粉含量。结果:分离纯化得到的直链与支链淀粉蓝值分别为0.979和0.144,分别落在0.8~1.2与0.08~0.22范围内,表明纯化后木薯直链与支链淀粉的纯度较高;直链淀粉在0~80mg/L质量浓度范围内其碘复合物与吸光度呈线性关系(r=0.9992),支链淀粉在0~220mg/L质量浓度范围内其碘复合物与吸光度呈线性关系(r=0.9995)。结论:正丁醇结晶法能有效地分离木薯直链与支链淀粉;双波长法操作快速、准确,无需分离即可同时测定木薯淀粉样品中直链和支链淀粉含量。  相似文献   

11.
Sweet potato (Ipomoea batatas) is a commonly cultivated root crop in tropical and subtropical regions, including Ghana. Different varieties of sweet potato have been bred, in order to expand its utilisation within the food and industrial sector. This study analysed flours made from 12 recently developed Ghanaian sweet potato varieties in terms of their amylose and amylopectin molecular fractions and amylopectin chain length distribution. Starch content of the sweet potato flours ranged from 49 to 77 g/100 g dry matter, with 11 of the varieties containing above 60 g/100 g dry matter. An orange-fleshed variety, Apomuden, had the lowest amount of starch (48.9 g/100 g dry matter), while the cream-fleshed variety Histarch had the highest (77.3 g/100 g dry matter). The flours from the 12 sweet potato varieties had intermediate amounts of amylose, within the range 10–30 g/100 g dry matter, and showed typical molecular distribution according to size-exclusion chromatography (SEC). The fine structures of amylopectin, as revealed by anion-exchange chromatography, contained features common for starches of C-type X-ray pattern, but some structural differences were also observed.  相似文献   

12.
为研究Wx基因的缺失对小麦淀粉生物合成的影响,本研究以8个Wx小麦近等基因系为材料,在灌浆期的10、20、30和40 d取籽粒测定直链淀粉、支链淀粉、总淀粉的含量及合成速度。结果表明:直链淀粉、支链淀粉和总淀粉含量及积累速率在花后逐渐增加,以花后10~20 d最大,此后逐渐降低。3个Wx基因对直链淀粉的含量及积累速率的影响依次为Wx-B1Wx-A1Wx-D1;小麦Wx基因型对直链淀粉的合成及积累速率影响较大,而对支链淀粉的影响较小,其对总淀粉含量及其积累的影响主要通过直链淀粉进行。  相似文献   

13.
以马铃薯淀粉为原料,淀粉回生率为考察指标,研究酵母菌发酵对马铃薯淀粉回生率的影响。通过对比发酵前后马铃薯回生淀粉的可见和红外吸收曲线,分析了酵母菌发酵提高马铃薯淀粉回生率的机理。结果表明,纤细酵母菌发酵马铃薯淀粉可使马铃薯淀粉回生率由12%提高到39.4%,提高了2.28倍。发酵后马铃薯回生淀粉中直链淀粉的最大可见吸收波长为587.8 nm,大于发酵前的569.6 nm。酵母菌发酵马铃薯淀粉提高其回生率的原因有两方面:一是发酵过程产生的酶使马铃薯支链淀粉脱支生成直链淀粉,增加了参与回生直链淀粉的量;二是发酵过程使马铃薯淀粉中醛基部分转变为伯醇基,进而生成糖苷键,增加直链淀粉链长,有利于淀粉回生过程晶体长大。  相似文献   

14.
Amylose forms inclusion complexes with lysophosphatidylcholine (LPC), that decrease the susceptibility of amylose to amylase degradation. This study on the influence of complexation on starch susceptibility to amylase explains the nature of this protective effect. Wheat starch suspensions (9% w/w) containing 0.5–5% LPC were subjected to hydrolysis by porcine pancreatic α-amylase at 37 °C for several digestion times. The digesta were analysed by size-exclusion chromatography (SEC). The molar mass distribution was closely dependent on the digestion time and amount of LPC. This study precisely demonstrates the alteration of the digestion profile of starch on a molecular level, influenced by amylose-LPC complexation; however the effect depends on the digestion time. During 15 and 30 min digestion, inclusion complexes not only protect amylopectin in the initial hydrolysis stage, but also demonstrate lower susceptibility of the molecular amylose complexes to amylase hydrolysis. Digestion for 240 min resulted in a lower oligosaccharide peak concentration, in the presence of a high LPC concentration, which is related to less degradation of complexed amylose fraction.  相似文献   

15.
Amylose Chain Association Based On Differential Scanning Calorimetry   总被引:5,自引:0,他引:5  
Amylose and lipid depleted starches from amylomaize, pea, maize, wheat, potato, and waxy maize were heated from 20°C to 180°C, cooled to 4°C, and then reheated to 180°C in a differential scanning calorimeter (DSC) in excess water. Cooling curves of the amylose and starch melts showed exothermic transitions (< 70°C) attributed to the mechanism of amylose chain association. Amylose/amylopectin mixtures covering the range 0–95% amylose were similarly heated and cooled. The association of linear amylose chains was restricted by amylopectin.  相似文献   

16.
A combination of freeze-dried powder of disproportionating enzyme (D-enzyme)-containing potato tuber and β-amylase-containing ramie leaf was used to improve the gluten-free (GF) bread, and its physicochemical properties were characterized. The presence of D-enzyme and β amylase in the potato tuber and ramie leaf was confirmed. Sixty five percent of partially gelatinized rice flour and 20% corn starch was combined with 10% freeze-dried potato tuber and 1% ramie leaf powder, and baked. The specific volume increased by 23% compared to the control with improved internal characteristics. Texture profile analysis revealed that retrogradation of the bread was retarded when stored for 90 h at 4 °C. The bread crumb amylose content was reduced from 14 to 9% and amylopectin branch chain-length distribution was rearranged, whereby the proportions of the branch chains with Degree of polymerization (DP) < 9 and DP > 19 decreased. The results suggest that D-enzyme and β-amylase cooperatively altered amylose/amylopectin ratio and amylopectin structure.  相似文献   

17.
燕麦发芽过程中淀粉及其相关酶活性的动态变化   总被引:2,自引:0,他引:2  
徐建国 《中国粮油学报》2012,27(4):25-27,49
研究了裸燕麦发芽过程中淀粉及其相关酶活性的动态变化。结果表明,发芽过程中,燕麦还原糖和可溶性糖含量及α-淀粉酶、β-淀粉酶和总淀粉酶活力明显地先增加后降低;直链淀粉、支链淀粉和总淀粉的含量均随着发芽的进行呈下降趋势,发芽72 h分别降低了25.86%、11.08%和17.31%。相关性分析表明,燕麦发芽期间还原糖、可溶性糖含量分别与α-淀粉酶、β-淀粉酶及总淀粉酶活力呈显著正相关,而直链淀粉、支链淀粉及总淀粉含量均与淀粉酶活力呈显著负相关。  相似文献   

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