玛咖淀粉与马铃薯、淮山药淀粉的理化性质比较

以马铃薯和淮山药淀粉为对照,研究了玛咖淀粉的化学组分、颗粒形貌、结晶结构、热力学性质、溶解度、膨胀度、糊透明度和冻融稳定性。结果表明,玛咖淀粉颗粒呈现椭圆形或不规则形,颗粒长轴在7.2~15.6μm之间,短轴在5.1~9.8μm之间;其偏光十字呈现垂直交叉,X-射线衍射结晶结构为C型,且在衍射角(2θ)为20°附近有直链淀粉-脂类复合物的特征吸收峰。玛咖淀粉的颗粒形貌和结晶结构与淮山药淀粉相似。玛咖淀粉的糊化温度较马铃薯和淮山药淀粉低,该淀粉糊化的起始温度(To)、峰值温度(Tp)和终止温度(Tc)分别为46.88℃、50.42℃和54.82℃,糊化焓变7.37 J/g。玛咖淀粉的溶解度和糊透明度比淮山药淀粉高,比马铃薯淀粉低;其峰值黏度与山药淀粉相近,显著低于马铃薯淀粉;膨胀度和冻融稳定性均优于马铃薯和淮山药淀粉。玛咖淀粉作为一种淀粉新资源,具有一定的开发价值和广阔的发展前景。     

压热法制备淮山药抗性淀粉及其消化性

研究压热法制备淮山药抗性淀粉的影响因素与抗性淀粉得率的关系,采用三因素二次通用旋转组合设计,优化淮山药抗性淀粉的制备工艺,试验结果表明:淀粉乳含量、pH值、压热时间对抗性淀粉得率的影响极显著,影响因素主次顺序依次为淀粉乳含量、淀粉乳pH值和压热时间;最佳工艺条件为淀粉乳含量25.20%,pH6.26,压热时间42.85 min,在此条件下测得的淮山药抗性淀粉得率为25.27%。In-Vitro体外模拟人体消化的试验表明,淮山药抗性淀粉较淮山药原淀粉更难消化,且抗性淀粉含量越大越难以消化。     

不同品种芸豆淀粉及其抗性淀粉结构和物化特性比较

探究不同品种芸豆淀粉、抗性淀粉的结构特征和理化性质。以不同品种芸豆为原料,分别采用碱法和压热酶解法制备芸豆淀粉及其抗性淀粉,利用扫描电镜、傅里叶红外光谱仪、RVA黏度仪等研究不同品种芸豆淀粉和抗性淀粉的分子结构及物化特性。结果表明:与原淀粉相比,抗性淀粉颗粒形貌及晶型结构改变;芸豆淀粉及抗性淀粉官能团和化学键组成相同。红芸豆淀粉糊化温度最低、最终黏度和回生值较高;与淀粉相比,各抗性淀粉糊化温度显著升高,糊黏度降低,芸豆淀粉及抗性淀粉的溶解度和膨胀度均与温度呈正相关,芸豆抗性淀粉的冻融稳定性降低。结论:不同品种芸豆淀粉分子结构特征相同,物化特性不同;压热酶解改变抗性淀粉颗粒形貌及晶型结构;不同品种芸豆抗性淀粉物化特性不同。     

豌豆淀粉与马铃薯淀粉、玉米淀粉理化性质比较

通过对豌豆淀粉、马铃薯淀粉和玉米淀粉的基本组成、颗粒形态、凝沉性、糊化特性、透明度及抗性淀粉含量的测定与比较表明:豌豆淀粉中直链淀粉和蛋白质的含量较高,但其颗粒直径小于马铃薯淀粉;与马铃薯淀粉和玉米淀粉相比,豌豆淀粉易于回生,但糊稳定性较好;豌豆淀粉糊的透明度低于马铃薯淀粉,但其淀粉组成中慢消化淀粉含量高于马铃薯淀粉和玉米淀粉。     

苦荞淀粉颗粒及淀粉糊性质研究

为明确苦荞籽粒淀粉理化特性,以7个苦荞品种为材料,分析了其淀粉颗粒表面结构及其淀粉糊的透明度、冻融稳定性、凝沉性、糊化特性、热焓特性。结果表明,苦荞淀粉颗粒多为不规则多面体球形,颗粒大小平均为6.8μm;苦荞淀粉糊的透明度平均为7.68%,低于玉米淀粉糊;苦荞淀粉糊凝沉性、冻融稳定性均强于玉米淀粉糊;苦荞淀粉的峰值黏度、谷值黏度、最终冷黏度、破损值及回生值均高于玉米淀粉;苦荞淀粉糊具有较强的热黏度稳定性、冷黏度稳定性和凝胶形成能力;苦荞淀粉糊的平均糊化温度范围为65.87℃到78.41℃,峰值温度为70.88℃,均低于玉米淀粉糊。     

小麦抗性淀粉物理性质研究

采用微波—酶法制备小麦抗性淀粉,用扫描电子显微镜(SEM)观察小麦抗性淀粉颗粒结构,用X-射线衍射仪测定其结晶结构,并测定抗性淀粉持水性、乳化性、粘度等物理特性。研究结果表明,与原小麦淀粉相比,小麦抗性淀粉表面粗糙,形状变得不规则,结晶结构为B型和V型结合体,持水性大于原淀粉,而乳化能力和乳化稳定性均低于原淀粉;在相同溶液浓度条件下,抗性淀粉粘度比原淀粉低得多。     

西米醋酸酯淀粉物化性质研究

利用扫描电子显微镜、聚焦光束反射测量仪,红外光谱仪和布拉班德粘度计对西米醋酸酯淀粉性质进行测定和分析,并与马铃薯醋酸酯淀粉进行比较。结果表明:马铃薯淀粉较西米淀粉更易引入乙酰基,乙酰化后淀粉颗粒形状未发生大的改变,西米原淀粉粒度分布为单峰,而马铃薯原淀粉粒度分布为双峰,前者平均粒径大于后者,乙酰化后西米淀粉和马铃薯淀粉粒径均增大;经醋酸酐酯化后西米淀粉和马铃薯淀粉起糊温度、峰值温度及峰值粘度均降低,热稳定性增加,凝沉性变弱。     

淮山药抗性淀粉的制备及共性质

采用酸变性和沸水浴的方法,对淮山药淀粉进行处理,以抗性淀粉得率作为评价指标,通过正交实验得出淮山药抗性淀粉的最优制备条件为:淀粉与水比例1:9,酸用量3%,酸解时间3h,沸水浴时间3.5h,冷藏老化时间36h,抗性淀粉得率12.25%.与原淀粉比较,淮山药抗性淀粉耐酸性增强,可长时间抵抗酶的水解,吸湿性有所提高.     

马铃薯抗性淀粉理化性质的研究

以马铃薯原淀粉为对照,研究了纤维素酶-压热法制备的马铃薯抗性淀粉的理化性质。结果表明,马铃薯原淀粉颗粒呈椭球形,表面光滑;而抗性淀粉的颗粒状结构消失,形成了连续的致密结构,表面不再光滑。红外光谱分析表明,抗性淀粉分子中未出现新的基团,只较原淀粉形成了更多的氢键。马铃薯原淀粉的分子晶型为A型,整体结晶度为22.82%;抗性淀粉的分子晶型为B型,整体结晶度为29.64%。马铃薯抗性淀粉的溶解度、透明度远远低于原淀粉;膨润度、持水性优于原淀粉。抗性淀粉的沉降速度较快,沉降性比原淀粉强。原淀粉糊化温度为65.8 ℃,峰值黏度可达到10 770 mPa·s;而抗性淀粉其糊化温度高于95 ℃。     

紫山药淀粉与其抗性淀粉理化性质的比较

以紫山药淀粉为研究原料,采用不同方法分别制备压热、酶解-压热及双酶纯化抗性淀粉,分析比较了紫山药淀粉与其抗性淀粉的理化性质。试验结果表明:紫山药淀粉颗粒呈圆形或椭圆形且表面光滑;抗性淀粉颗粒破碎且呈不规则型。4种淀粉的化学结构相似,与原淀粉相比,抗性淀粉没有生成新的基团。抗性淀粉样品的凝沉速度随直链淀粉含量的增加而加快,冻融稳定性则降低;碘吸收曲线向支链淀粉吸收波长方向偏移。流变学分析表明与原淀粉相比抗性淀粉表观黏度均增大,剪切结构恢复力与抗性淀粉含量成反比。     

铁棍怀山药中主要营养成分的研究

测定铁棍怀山药中的主要营养成分,并与普通淮山药的相应指标进行对照。结果表明,新鲜铁棍怀山药中固形物含量达28.67%,远高于普通淮山药13.86%的指标。铁棍怀山药中总氮量、总灰分、淀粉和粘性多糖含量分别为0.616%、2.03%、15.29%和1.59%,也高于普通淮山药的0.154%、1.36%、6.57%和1.47%的指标。证实铁棍怀山药比普通淮山药的营养与药用价值更高,值得进一步的研究和开发。     

山药及零余子酸、酶处理淀粉的理化性质

利用酸和淀粉酶、糖化酶分别处理山药及零余子淀粉,利用扫描电镜、X射线衍射及流变仪等测定不同处理组淀粉的理化特性。结果表明：山药和零余子原淀粉颗粒较为完整,没有裂缝,呈卵圆形,表面光滑;酶、酸处理均会导致淀粉降解,酸处理淀粉表面破坏最为严重;零余子原淀粉、酸处理和酶处理的淀粉结晶度分别为32.02%、27.02%和31.13%,而山药原淀粉、酸处理和酶处理淀粉结晶度分别为34.32%、29.27%、33.55%。淀粉糊透光率、凝沉百分比表明零余子原淀粉最易老化,流变特性表明不同处理组的淀粉均具有弱凝胶特性。     

The effect of acid and glucoamylase hydrolysis on partial physicochemical properties and characteristics of Dioscorea alata Linn. starch

Dioscorea alata Linn. (D. AL) rich in starch was widely used as food and medicine. This work aimed to compare the effect of acid and glucoamylase on the starch of different reaction time. The physicochemical properties of the native and hydrolyzed starches, such as swelling power (SP), starch solubility (SOL), and paste clarity were also determined in this study. The native and modified starches by acid and glucoamylase were compared and characterized by scanning electron microscope (SEM) and secondary derivative FT‐IR spectroscopy. The morphological characteristics of native D. AL starch granules revealed by SEM varied from round to oval or elliptic with smooth surface. SEM showed that glucoamylase primarily attacked the exterior of starch granules and permeate into the interior by the cracks formed on the surface. Owing to acid hydrolysis, the starch granules were depressed and transformed to bread‐like in shape and then broke into irregular lumps with particles adhered. From secondary derivative FT‐IR spectrum, the intensities of the two peaks from acid and enzyme hydrolysis starches at 1137 and 1066/cm were stronger than native starch. Some new peaks appeared due to hydrolysis. The digested starches exhibited a lower SOL and SP than native starch in water as the temperature increasing. The light transmittance of the digested starches was significantly higher than that of native starch paste and decreased with increase in storage period.     

长山山药淀粉的制备及性能

以长山山药为原料,采用碱法工艺提取山药中的淀粉。对山药淀粉的颗粒特性、理化特性、糊化动力学、结晶类型等进行研究和分析。扫描电子显微镜观察发现长山山药淀粉的颗粒大都呈圆形或椭圆形,表面光滑;粒径分析结果显示山药淀粉颗粒的粒径分布主要呈单峰曲线变化,峰值粒径为48.57μm、中位径为22.72μm;偏光显微镜观察发现山药淀粉颗粒有明显的偏光十字;山药淀粉溶液在95℃时溶解力为16.78%,膨润力为33.55%;淀粉糊化之后的透明度为23.2%;淀粉糊凝沉稳定性为6 h;淀粉糊析水率为48.20%;差示扫描量热仪测定结果显示淀粉糊化起始温度为72.50℃,终止温度为85.40℃;糊化动力学结果表明山药淀粉糊化属于一级反应;快速黏度分析仪测出山药淀粉的峰值黏度为6 220 cP,最低黏度为3 902 cP,最终黏度为5 702 cP,衰减值为2 318 cP,回生值为1 800 cP;X射线衍射结果表明山药淀粉的结晶类型为C型。     

Effect of phosphoric acid treatment on physicochemical,functional, and structural properties of starch extracted from yam (Dioscorea rotundata)

This work was designed to elucidate selected physicochemical, functional, and structural properties of native and modified yam (Dioscorea rotundata) starch. The isolated starch was chemically modified using 5, 10, 15, 20, and 25% phosphoric acid solution at 50°C for 1 h, and yield, swelling power, gelation, water holding capacity, paste clarity, blue value, and amylose and amylopectin content of the native and modified yam starch were determined. Structural changes in the native and starch modified with 25% phosphoric acid were evaluated using Fourier transform infrared spectroscopy and optical microscopy. The result showed that the yield, swelling power, water holding capacity, paste clarity, blue value and amylose and amylopectin content of native yam starch was 33.38% (217 g), 3.84 g/g, 1.0 v/g, 10%, 0.52 and 25.96, respectively, whereas gelation study of the native and modified starch indicated that native starch was viscous and modified starch firm. However, yield, swelling power, water holding capacity, paste clarity, blue value, and amylose content of modified yam starch reduced in a dose dependent manner with phosphoric acid. The reduction in the values of the various functional properties could be associated with the effect of phosphoric acid on the starch granular structure. The result of Fourier transform infrared spectroscopy and optical microscopy revealed that the yam starch was modified by phosphoric acid with changes in functional groups spectra such as –OH stretch (3177 cm^?1), H₂O absorbed (1644 cm^?1) (amorphous region), C-H stretch (2923 cm^?1), CH₂O (1253 cm^?1), and C-O-C (1078 cm^?1) when compared to native starch. The morphology of native and modified yam starch granules ranged from oval to eliptical. However, modified starch granules were rough in surface. In conclusion, the characterized physicochemical and functional properties and structure exhibited by native and modified yam starch indicated that, yam could be a cheap and valuable source of starch for industrial application.     

Effect of heat-moisture treatment on the formation and physicochemical properties of resistant starch from mung bean (Phaseolus radiatus) starch

Mung bean starch was subjected to a range of heat-moisture treatments (HMT) based on different moisture contents (15%, 20%, 25%, 30%, and 35%) all heated at 120 °C for 12 h. The impact on the yields of resistant starch (RS), and the microstructure, physicochemical and functional properties of RS was investigated. Compared to raw starch, the RS content of HMT starch increased significantly, with the starch treated at 20% moisture having the highest RS content. After HMT, birefringence remained at the periphery of the granules and was absent at the center of some granules. The shape and integrity of HMT starch granules did not change but concavity was observed under scanning electronic microscopy. Apparent amylose contents of HMT starch increased and the HMT starch was dominated by high molecular weight fraction. Both the native and HMT starches showed A-type X-ray diffraction pattern. Relative crystallinity increased after HMT. The gelatinization temperatures (To, Tp, and Tc), gelatinization temperature range (Tc–To) and enthalpies of gelatinization (ΔH) increased significantly in HMT starch compared to native starch. The solubility increased but swelling power decreased in HMT starches. This study clearly shows that the HMT exhibited thermal stability and resistance to enzymatic hydrolysis owing to stronger interactions of starch chains in granule.     

西米淀粉的物化性质研究

研究了西米淀粉的组成、颗粒形貌及糊化、透明度、老化方面的性质,并与木薯和马铃薯进行了比较。结果表明,西米淀粉的蛋白质含量为0.21%,直链淀粉含量为28%,颗粒为椭圆形,西米淀粉的起糊温度为70.3℃,热糊稳定性高,凝沉性比薯类淀粉弱,西米淀粉的透明度为57.5%,比薯类淀粉易老化。为进一步了解西米淀粉的特性及应用开发提供了一定的理论依据。     

西米辛烯基琥珀酸淀粉酯的结构表征及性质研究

采用现代仪器分析方法对西米辛烯基琥珀酸淀粉酯的结构特征、颗粒形貌、粒径分布、乳化性、糊粘度等性质进行了测定和研究,并以西米原淀粉作为参照。结果表明,西米淀粉经辛烯基琥珀酸酐处理后,产品的红外光谱在1570cm-1和1714cm-1处出现新的吸收峰,608cm-1处吸收峰加强;颗粒表面受到损害,形状发生不规则变化;颗粒粒径分布不均,平均粒径大于西米原淀粉;乳化能力和乳化稳定性有显著提高;糊粘度明显增大,热糊稳定性高,凝沉性较弱。为进一步研究西米辛烯基琥珀酸淀粉酯的开发应用提供了一定理论依据。