超声处理对马铃薯淀粉结构特性及理化性质的影响

为了研究超声对马铃薯淀粉微观结构及理化性质的影响,以马铃薯淀粉为原料,通过扫描电子显微镜、激 光共聚焦显微镜、X射线衍射、傅里叶变换红外光谱、差示扫描量热法、快速黏度分析、偏光显微镜观察等方法, 研究了超声对马铃薯淀粉微观结构及理化性质的影响,揭示超声对马铃薯淀粉的机械力化学效应。结果表明：由于 马铃薯淀粉颗粒内部“狭长的脐点区”结构比较疏松,超声处理对马铃薯淀粉可产生显著机械力化学效应;随着超 声时间延长,马铃薯淀粉颗粒内部依次经过受力阶段、聚集阶段、团聚阶段;同时由于超声处理引起了马铃薯淀粉 颗粒结构变化,故导致了马铃薯淀粉理化性质显著变化。     

酸热加工对焦糊精结构和理化性质的影响研究进展

抗性糊精是抗消化、低热量的膳食纤维,具有降低血糖血脂、改善肠胃功能、促进益生菌增殖等功效。焦糊精是制备抗性糊精中的关键中间产物,也是产生抗性的主要来源,制备焦糊精的过程会产生很多新的不被人体消化酶降解的糖苷键,从而赋予焦糊精和抗性糊精“抗消化性”。作者从焦糊精的制备、分子结构、理化特性、主要应用及未来发展趋势进行综述,以期能促进焦糊精行业的可持续健康发展。     

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。     

银杏淀粉颗粒结构及物化特性的研究

本文采用扫描电镜、X-射线衍射、快速黏度分析仪、HAKKE流变仪及差示量热扫描仪,对银杏淀粉的颗粒大小、晶体特性、热特性及物化特性进行了系统分析。实验结果表明:银杏淀粉呈圆形或卵圆形,粒径范围分布在5～20μm,为C型晶体,结晶度39.9%。银杏淀粉的糊化温度高于玉米和木薯淀粉;糊透明性和冻融稳定性好;但凝沉性差;温度与黏度系数符合Arrhenius方程η=45.672e-0.094/R(T 273.2)(R2=0.9746),温度和流变指数a=2E-5T2-0.0025T 0.6157(R2=0.9685)。热力学参数分别为To72.34℃、Tp76.69℃、Tc80.08℃和ΔH5.79J/g干重。     

Structure,Physicochemical Properties,Modifications, and Uses of Sorghum Starch

Sorghum has great drought resistance and can be cultivated on marginal lands with minimal input costs. Thus, the supply of sorghum starch, the major component of the seeds, can be cheap and sustainable. This review summarizes the present knowledge of extraction, composition, granular and molecular structures, physicochemical properties, modifications, and uses of sorghum starch, and provides suggestions for needed research to improve our understanding and utilization of this starch.     

Effect of Gamma Irradiation on Molecular Structure and Physicochemical Properties of Corn Starch

ABSTRACT:  Carboxyl content and amylose leaching of gamma-irradiated corn starch increased and swelling factor decreased with increasing radiation dose. The apparent amylose content decreased gradually from 28.7% for native starch to 20.9% for 50 kGy irradiated starch. The proportion of short amylopectin branch chains (DP 6 to 12) increased, while the proportion of longer branch chains (DP ≥ 37) decreased with increasing radiation dose. The relative crystallinity and the degree of granule surface order decreased from 28.5% and 0.631 in native starch to 26.9% and 0.605 in 50 kGy irradiated starch, respectively. Pasting viscosity and gelatinization temperatures decreased with an increase in radiation dose. At a high dose (50 kGy), melting of amylose–lipid complex in DSC thermogram was not observed. The rapidly digestible starch (RDS) content slightly decreased up to 10 kGy but increased at 50 kGy. The resistant starch (RS) content slightly decreased at 2 kGy and then increased up to 50 kGy. The slowly digestible starch (SDS) content showed the opposite trend to RS content. Slower irradiation dose rate reduced carboxyl content, swelling factor, and amylose leaching. The apparent amylose content and amylopectin chain length distribution were not significantly affected by dose rate of gamma irradiation. However, the relative crystallinity and gelatinization enthalpy increased with slower dose rate. Slower dose rate decreased RDS and SDS contents, and increased RS content.     

微波对板栗淀粉结构和理化性质的影响

为探讨微波辐照对板栗淀粉颗粒结构和理化性质的影响,采用微波辐照板栗淀粉,通过扫描电镜(SEM)、X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)、差示扫描量热仪(DSC)等研究微波处理不同时间后板栗淀粉的颗粒结构和理化特性。研究表明:与原淀粉相比,微波处理后板栗淀粉的微观形貌发生明显变化,但淀粉颗粒仍为C型晶体。随着微波处理时间的增加,直链淀粉含量增大,淀粉颗粒表面出现裂纹、孔洞和黏结越显著,淀粉颗粒的相对结晶度降低、红外光谱(1 047/1 022)cm~(-1)峰强度比值降低;淀粉膨胀度和透光率也随微波处理时间的增加而降低。DSC分析表明,微波处理80 s的淀粉相转变温度(T_o和T_p)降低、糊化焓(ΔH)减少。表明微波辐照对板栗淀粉的颗粒结构和理化特征均有显著影响。     

野葛淀粉与木薯淀粉混粉理化特性分析

以野葛淀粉和木薯淀粉为原料,将木薯淀粉分别以10%、30%、50%和70%的质量分数掺入野葛淀粉。研究了原粉基本成分、原粉和混粉的结构、凝胶特性、抗氧化活性、热特性、冻融稳定性、消化特性、冲调特性。结果表明：随着木薯淀粉比例的增多,可以根据扫描电镜中的颗粒形状明显区别原粉及混粉,混粉平均粒径(10.68～13.05μm)均比野葛淀粉(9.47μm)高。野葛淀粉与木薯淀粉分别为C型及A型晶体结构,混粉后并未改变其结构及红外光谱图。混粉的糊化起始温度随添加量增加而显著升高(P<0.05),更难糊化。混粉抗氧化能力降低、多次冻融后趋于稳定、冲调黏度增大;混粉后硬度增大,最高达到2 410.46 g,质地硬化,凝胶性能变差;混粉的抗性淀粉(质量分数0.37%～1.59%)相对野葛淀粉较低(5.65%)。木薯淀粉的掺入对混粉影响较大,有利于从淀粉的结构和理化特性等方面为鉴别野葛淀粉中是否掺有木薯淀粉提供参考。     

双螺杆挤压温度对玉米淀粉结构和理化性质的影响

淀粉在挤压机内的熔融行为变化影响着挤出物的物理性质,探究淀粉挤压过程中熔融行为对于生产理想的热塑性淀粉基材料具有重要意义。本文探究不同挤压温度（60、70、80、90和100 ℃）对玉米淀粉结构和理化性质的影响。结果表明,在高温和机械剪切作用下,淀粉颗粒发生破碎,颗粒尺寸减小。淀粉分子内氢键被破坏,使淀粉更易与水分子结合,从而提高了热塑性淀粉（TPS）的水合特性。随着温度升高,直链淀粉含量增加,相对结晶度（RC）和双螺旋有序度（DO）减小,表明玉米淀粉在受热过程中长程和短程有序结构被破坏。挤压机的高温处理降低了TPS的焓值,破坏了淀粉糊形成凝胶网络的能力,样品存在弱凝胶行为,但刚性和弹性减弱。综上所述,双螺杆挤压温度使淀粉颗粒结构、晶体结构、水合特性和流变特性发生了不同程度的变化,为挤压优质热塑性淀粉材料提供新思路。     

鹰嘴豆淀粉与玉米淀粉性质的比较

研究了新疆产鹰嘴豆淀粉的一些基本性质,并与玉米淀粉进行比较,发现鹰嘴豆淀粉中直链淀粉质量分数为31.8％,高于玉米淀粉的直链淀粉质量分数(26.6％);通过电镜扫描发现鹰嘴豆淀粉颗粒表面光滑,形状多数为椭圆形、鹅卵石状,少数为圆形,而玉米淀粉颗粒多为圆形,呈多角状;粒度分析表明鹰嘴豆淀粉的粒径范围是6.39 ～41.8...     

韧化处理对大米淀粉性质的影响

为韧化处理在大米淀粉改性中的应用提供理论依据,作者以余赤早籼米为原料,在不同温度（50～70℃）和水分质量分数（45%～65%）条件下对大米进行韧化处理,然后提取韧化处理后大米中的淀粉,以未经韧化处理提取的大米淀粉为对照,研究韧化处理对大米淀粉溶解度、膨润力、糊化特性、消化特性和冻融稳定性的影响。研究结果表明：与对照组相比,经韧化处理的大米淀粉溶解度和膨润力降低;峰值黏度、最终黏度、谷值黏度、回生值和衰减值均有所降低,糊化温度升高,不同韧化处理温度对衰减值的影响差异显著;淀粉中RDS（快消化淀粉）质量分数升高,RS（抗性淀粉）质量分数减少,SDS（慢消化淀粉）质量分数随着韧化处理条件的不同而不同,说明韧化处理提高了大米淀粉的消化性,也使大米淀粉冻融稳定性下降。     

不同品种大米理化性质及其淀粉结构对米饭食用品质的影响

米饭食味值和质构特性是评价大米食用品质的重要指标,为了探究不同品种大米的食味值、质构特性与其理化性质及淀粉结构的关系,以12种大米为研究样本,测定其食味值、质构特性、理化性质及淀粉结构特性,并分析内在相关性。结果表明,直链淀粉含量（质量分数）与米饭的硬度呈极显著正相关（P<0.01）,与米饭的凝聚性呈极显著负相关（P<0.01）;米饭食味值、质构特性与大米淀粉的糊化特性、热特性之间存在显著相关性,与结晶特性、淀粉颗粒表面有序度无显著相关性,表明淀粉的糊化特性决定了米饭的食味值、硬度、凝聚性和回复性。该研究可为后期优质稻米筛选培育以及大米适宜性加工提供理论基础。     

不同加热-冻融循环处理对甘薯淀粉结构及物化特性的影响

本文研究了不同温度下(75、95和121℃)重复的加热-冻融循环处理对甘薯淀粉结构及物化特性的影响。采用扫描电子显微镜、X-射线衍射、差示量热扫描仪及快速黏度测定仪对甘薯淀粉的结构、结晶性质、热特性和糊化特性进行分析,并测定了其膨胀势、溶解度和体外消化性。75、95和121℃加热-冻融循环处理均使甘薯淀粉颗粒形态破坏或消失,呈不规则块状;75℃加热-冻融循环处理导致了甘薯淀粉结晶吸收峰及热吸收峰强度减弱,焓值降低、糊化温度升高且范围变小,而经95和121℃加热-冻融循环处理后,甘薯淀粉结晶型由A型向B型转化,热吸收峰消失;此外,甘薯淀粉溶解度随着加热-冻融循环次数的增加呈先降低后增加的趋势,各黏度特征值降低,回生趋势减弱,慢速消化淀粉(SDS)含量有所增加,121℃一次加热-冻融循环处理(RGR-1)后含量最高,可达29.25%。     

Impacts of acid-methanol treatment and annealing on the enzymatic resistance of corn starches

Normal corn, Hylon V and Hylon VII starches were acid-methanol-treated at 25 °C for 1–30 days in methanol containing 0.36% HCl, and then annealing at 50 °C for 72 h in excess water. The rapid digestible starch (RDS), slow digestible starch (SDS) and resistant starch (RS) contents of starch before and after treatments were determined. The molecular structure, thermal properties, double helix content and relative crystallinity of starch were observed for elucidating the impacts of acid-methanol treatment and annealing, as well as the molecular structure, on the enzymatic resistance of starch. Results showed that the weight-average degree of polymerization of acid-methanol-treated corn starches ranged from 884 × 10³ to 404, 778 × 10³ to 299 and 337 × 10³ to 250 anhydrous glucose units for normal corn, Hylon V and Hylon VII starches, respectively. Annealing increased the RS content of starch, and the increment of RS increased with decreasing molecular size of starch. Furthermore, the change in RS content after treatments depended on the content and weight-average chain length of amylose fraction of starch. The RS content of starch after treatments increased from 19.2 to 56.2%, 69.9 to 86.1%, and 73.1 to 89.1% for normal corn, Hylon V and Hylon VII starches, respectively. The gelatinization peak temperature and double helix content of starch increased after acid-methanol treatment or annealing. Results demonstrate that the degradation of starch, causing by acid-methanol treatment, enhances the mobility and realignment of starch chains in molecules during treatments and further increases the enzymatic resistance of starch granules.     

超声处理对糙米淀粉的结构与理化特性的影响

以糙米淀粉为原料,探究不同超声时间处理对糙米淀粉的分子结构及理化特性的影响.结果 表明:与原淀粉相比,超声处理10 min的改性淀粉的官能团和化学键组成没有变化.超声处理10 min能够将糙米淀粉的粒径显著降低43.18％,崩解值从577 cP降低到388 cP,峰值黏度经过超声处理后降低,在30 min达到最低157...     

淀粉球晶的制备及其理化性质

本文以蜡质玉米淀粉为试验原料,采用酶法脱支淀粉后重结晶制备淀粉球晶,通过对所制淀粉球晶的链长分布与分支度、回收率、球晶形貌特征、结晶度分析及热力学性质测定,考察异淀粉酶添加量和结晶时间对球晶理化性质的影响。结果表明:淀粉糊化后冷却至50℃加入25 U/g异淀粉酶反应24 h可使支链淀粉完全脱支,所得淀粉球晶平均链长为26.70;已脱支的淀粉于25℃条件下重结晶,回收率和结晶度随着结晶时间的延长而提高,结晶24 h回收率和结晶度分别为76.58%和51.1%;淀粉球晶的起糊温度(T_o)、峰值温度(T_p)、终止温度(T_c)和焓值(△H)高于原淀粉,且随着结晶时间的延长而呈现增大趋势;SEM图像显示,随着结晶时间的延长,淀粉球晶的颗粒度逐渐清晰,但淀粉球晶颗粒出现聚集现象。     

高粱自然发酵对淀粉分子结构及老化性质的影响

为明确自然发酵对高粱淀粉分子结构及老化性质的影响,将高粱进行自然发酵,利用碱提法提取高粱淀粉,研究发酵过程中淀粉颗粒表面形态、官能团、淀粉分子质量、链长分布的变化对淀粉老化性质的影响。结果表明：自然发酵后高粱淀粉颗粒表面有一定的侵蚀痕迹;发酵处理未生成新的化学基团,各官能团的峰位保持不变;发酵后淀粉的重均分子质量降低,低分子质量淀粉由74.2%增加到78.5%,同时高分子质量淀粉含量由5.4%降低至2.5%;支链淀粉的短支链百分含量降低1.8%～3.89%,长支链百分含量增加2.01%;发酵后淀粉的峰值黏度及回生值增加,其中回生值增加466?mPa·s,使发酵后的高粱淀粉更易形成凝沉,研究结果为自然发酵高粱技术调控及老化淀粉食品加工提供理论基础与数据支持。     

The Effects of Protein‐Rich Fraction and Defatting on Pasting Behavior of Chickpea Starch

Starch and protein‐rich fractions were isolated from both defatted and undefatted chickpea flour. Starch with a high purity was obtained by the isolation method used. Each of the protein‐rich fractions was added to the respective starch fraction at different levels to obtain mixtures with a range of protein contents. The viscosities of these mixtures were analyzed using the Rapid Visco Analyser (RVA). Increased protein content of the starch and protein‐rich fraction mixtures, obtained from defatted chickpea flour, resulted in distinctive resistance to shear thinning. The same behavior was not observed in case of starch and protein‐rich fraction mixtures obtained from undefatted chickpea flour. Undefatted samples exhibited a sharp pasting peak in RVA curves as generally expected from starch‐based systems, but unexpectedly, a sharp peak was not observed in defatted samples having protein content up to 4.8%. Peak, breakdown and cold‐stage viscosity values of the mixtures obtained from undefatted chickpea flour were higher than those of defatted ones at the corresponding protein levels. The results implied that the lipids and their interaction with starch played an effective role in the gelatinization, pasting and cooling stage viscosity values of the RVA curves.     

蒸汽爆破处理对籼米淀粉分子结构的影响

本文研究了蒸汽爆破作用强度对籼米淀粉分子结构的影响。采用蒸汽爆破的方法对籼米淀粉进行处理,利用凝胶色谱、紫外光谱和红外光谱等分析手段研究汽爆压力、维压时间和淀粉样品水分含量对籼米淀粉分子结构的影响。结果表明,籼米淀粉经蒸汽爆破处理后,随着爆破压力、爆破时间以及样品水分含量的增加,籼米淀粉分子量下降,短链片段所占比例增加,中间级分吸收峰逐渐消失;汽爆处理后的籼米淀粉分子链聚合度降低,紫外光谱最大吸收波长发生兰移现象;随着汽爆强度增加,淀粉分子链断裂产生的醛基增多,红外光谱1650 cm-1处醛基吸收峰强度增大,有序化结构与无序化结构的比例(结晶指数)变大。研究表明蒸汽爆破技术作为一种预处理方法可以有效的降解籼米淀粉分子链聚合度,增加淀粉结晶度。     

薏米淀粉的颗粒结构与性质研究

淀粉是薏米的主要成分，其结构和性质对薏米的加工和薏米食品的品质有重要的影响。本文研究了薏米淀粉颗粒的表面结构、偏光十字、X-衍射图谱和结晶结构，以及薏米淀粉糊的粘度曲线等特性，为薏米食品的开发提供理论基础。