Pasting,Thermal, Hydration,and Functional Properties of Annealed and Heat-Moisture Treated Starch of Sword Bean (Canavalia gladiata)

The effects of annealing (ANN) and heat-moisture treatments (HMT) on the physicochemical and functional properties of Sword bean starches were investigated. The pasting properties differ significantly among the starches, with peak viscosity ranging from 399.17 RVU to 438.33 RVU; however, all the starches exhibited ‘Type C’ class with restricted swelling. The HMT starches had the highest gelatinization temperature, while change in enthalpy of gelatinization, ΔH_gel of the native starch, was higher (13.82 J/g) than that of the modified starches (1.39–6.74 J/g). The solubility and swelling power of all the starches increased as the temperature increased. The oil and water absorption capacity of the starches ranges between 3.24–3.91 g/g and 2.42–3.35 g/g, respectively. HMT (at 25 and 30% moisture level) changes the X-ray diffraction pattern of the starch from Type ‘B’ to Type ‘C’. The Scanning electron micrograph results revealed the starch granules with smooth ellipsoids and indentation in their centre, hydrothermal modification showed little effect on the morphology and size of the granules. Hydrothermal modification improved the physicochemical and functional properties of the starch without destroying the granule of the starch.     

Chemical Modification of Jack Bean (Canavalia ensiformis) Starch by Succinylation

Canavalia ensiformis native starch was succinylated and the functional properties of the succinylated starch evaluated. Reaction conditions investigated included: pH (8.0—8.5 and 9.0—9.5), succinic anhydride concentration (3 and 4%), temperature (20 and 30 °C) and reaction time (1 and 3 h). When starch was succinylated with 4% succinic anhydride, at pH 8.0—8.5, at 30 °C for 1 h, 1.58% succinylation was obtained. Compared to native Canavalia starch, these succinylated products exhibited increasing paste and gel clarity, solubility (36%), swelling power (46.2 g water/g starch), and viscosity (86.5 mPas). Gelatinization temperature range was reduced to 67—73 °C and retrogradation was eliminated. The use of succinylated Canavalia starches as thickening and stabilizing agents in ice creams, fruit jellies, baked products, sauces and frozen foods is suggested.     

发芽对糙米淀粉理化特性的影响

以未发芽、发芽12、24、36 h的糙米为原料提取淀粉,并对淀粉及其组分含量、淀粉糊的透明度、凝沉性质、冻融稳定性、酶解率以及粘度等进行分析,研究发芽对糙米淀粉理化特性的影响。结果表明:糙米发芽后淀粉及其组分的含量、淀粉糊的酶解率以及淀粉糊的粘度均降低;淀粉糊的透明度和冻融稳定性均增强;凝沉稳定性变化不大。其中发芽24 h的糙米淀粉的理化特性变化最明显。发芽对糙米淀粉的理化特性具有一定的改善作用。     

The Effect of Micronization Operational Conditions on the Physicochemical Properties of Navy Beans (Phaseolus vulgaris L.)

Micronization conditions for processing navy beans were evaluated relative to micronizer outlet temperature, final moisture content, hardness, soluble protein, hydration capacity, and density using a full factorial experiment. Processing variables included conveyer bed slope (SL), setting of gas‐air mixture valve (GS) or gas/air ratio, and distance between conveyer bed and infrared radiation source (DS). As SL and the gas/air ratio increased, the final temperature of the micronized navy beans increased but bean moisture content was reduced. The percent soluble protein and hydration capacity also were reduced as SL increased. The contribution of DS to the characteristics of beans micronized under these conditions was minimal. Recommended conditions were best determined based on outlet temperature.     

Physicochemical Properties of Starch Isolated from Bracken (Pteridium aquilinim) Rhizome

Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X‐ray diffraction analysis revealed that bracken starch exhibited a typical C‐type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch.     

不同功率超声波对芸豆蛋白理化和功能性质的影响

研究超声波处理对芸豆蛋白(KBP)理化和功能性质的影响.分别探讨了不同超声波功率对芸豆蛋白的紫外光谱、荧光光谱等理化性质及溶解度、吸油性、起泡性能和乳化性能等功能性质的影响.结果表明,超声波处理对芸豆蛋白的紫外光谱和荧光光谱有明显的影响;芸豆蛋白的溶解度随超声波功率增加而逐渐提高,芸豆蛋白400 W时的起泡性和起泡稳定性、500 W时的乳化性和乳化稳定性和200 W时的吸油性最高.说明适宜的超声波功率水平能够改善芸豆蛋白的理化性质和功能性质.     

红小豆淀粉理化性质研究

以红小豆为材料,采用水磨法提取红小豆淀粉,以玉米淀粉、红薯淀粉作对照,对其颗粒特性以及糊化黏度特性等理化特性进行研究。实验结果表明,红小豆淀粉颗粒呈椭圆卵形,颗粒完整,表面光滑,粒径较长,偏光十字明显,具有类似树木年轮的轮纹结构,脐点位于颗粒中心。与对照相比,红小豆淀粉具有较低的糊化温度,较高的糊黏度,较差的冷热稳定性,易发生老化。pH、蔗糖对红小豆淀粉糊的黏度性质有影响。     

无明矾薯类鲜湿粉条的加工工艺优化及其理化特性

为优化无明矾薯类鲜湿粉条的加工工艺,以混合薯类淀粉（马铃薯淀粉:木薯淀粉=1:1,m/m）为原料,以无明矾鲜湿粉条和0.30%明矾鲜湿粉条作为对照,探索了海藻酸钠添加量、成型时间、冷藏及冷冻时间等对无明矾薯类鲜湿粉条质构特性、水分含量及整体可接受性的影响规律;在此基础上,对比了不同老化方式对无明矾薯类鲜湿粉条断条时间、表观及微观结构（扫描电镜、傅里叶红外光谱、小角X射线散射）的影响。结果表明：添加1%海藻酸钠后,薯类鲜湿粉条的拉伸强度（2.86 g/mm2）、拉伸形变（63.88%）、剪切应力（39.89 g/mm2）、剪切形变（37.76%）、水分含量（60.40%）和整体可接受性与0.30%明矾粉条最为接近,说明1%海藻酸钠可作为明矾替代物来加工无明矾薯类鲜湿粉条;此外,无明矾薯类鲜湿粉条的加工工艺条件为成型时间1 min、4 ℃冷藏24 h,该条件下薯类鲜湿粉条的弹性和咀嚼性较好、断条时间显著延长、表观结构更为均匀。本研究结果可为无明矾薯类鲜湿粉条的产业化应用提供新的基础数据和理论依据。     

甘薯抗性淀粉理化特性研究

选择3个不同类型甘薯品种,以提取获得的抗性淀粉为研究对象,通过X-射线衍射分析仪、差示扫描量热分析仪(DSC)、快速黏度测定仪(RVA)、紫外-可见吸收光谱仪、近红外光谱分析仪(NIRS)和扫描电镜等仪器分别对甘薯原淀粉和其对应抗性淀粉晶体结构类型、熔融温度、淀粉糊化特性、平均聚合度和淀粉分子结构等理化特性深入研究与分析。结果表明,不同甘薯品种间抗性淀粉熔融温度具一定差异,抗性淀粉与其原淀粉间糊化特性、晶体结构等特性呈明显差异。     

Sword bean (Canavalia gladiata) as a source of antioxidant phenolics

Sword beans (Canavalia gladiata) have been used as grain legumes and medicinal plants in China for thousands of years. To explore new natural antioxidant sources, the antioxidant capacity and phenolic composition in the soluble and bound fractions of three sword bean genotypes were evaluated in vitro. The red and black sword beans were found to have antioxidant capacity compared to the white sword bean, and this was attributed to their red and black bean coats, which possessed extremely high phenolic content. Gallic acid and its derivatives, such as methyl gallate, digalloyl hexoside and digallic acid, were the main phenolic compounds in the coats of red and black sword beans. Therefore, the red and black sword beans, especially their bean coats, are good sources of antioxidant phenolics and may have potential health benefits.     

α-淀粉酶水解对芭蕉芋淀粉理化性质的影响

目的酶法水解为芭蕉芋淀粉进行改性,提高芭蕉芋淀粉的应用价值,扩大于其在食品工业的应用范围。方法以芭蕉芋淀粉为原料,采用α-淀粉酶水解制备酶解淀粉,结合热失重(TGA)技术考察α-淀粉酶水解对芭蕉芋淀粉热稳定性和其他理化性质的影响。结果与原淀粉相比,酶解淀粉的溶解度和膨胀度、吸水度和吸油度增大;透光率和冻融稳定性降低;TGA结果表明,α-淀粉酶水解不改变芭蕉芋淀粉的组成成分,且酶解芭蕉芋淀粉的分解温度较高,表明其热稳定性增加。结论通过α-淀粉酶酶解法可制备满足工业需要的改良芭蕉芋淀粉。     

机械活化对玉米乙酰化淀粉理化特性的影响

采用搅拌球磨机对玉米淀粉进行机械活化,以活化时间为60 min的玉米淀粉和原淀粉为原料制备乙酰化淀粉.研究了机械活化对玉米乙酰化淀粉理化特性影响.结果表明,机械活化预处理的玉米乙酰化淀粉的溶解度、糊透明度增大.冻融稳定性增强,凝沉性降低,糊黏度增大及其热稳定性提高.机械活化作用破坏了淀粉的结晶区,结晶程度降低,有效地改善了乙酰化淀粉的理化特性.     

热加工对淀粉结构和理化性质的影响研究进展（网络首发、推荐阅读）

淀粉是一种非常重要的植物多糖,同时也是重要的食品生产加工的工业原料。天然淀粉耐热、耐剪切、耐酸能力差,且易回生,需要对淀粉进行物理改性、化学改性和酶改性。在淀粉改性尤其是化学改性中,化学试剂易残留于改性淀粉中,所以快速、安全的物理改性越来越受到大家关注。而物理改性中,热加工改性应用较为广泛。通过概述六种常用的热加工改性技术对淀粉结构及性能的影响,旨在为热加工改性淀粉理化性质的研究提供理论参考,以期能为特定需求淀粉的生产研发提供一定的理论依据。     

发酵对于淀粉理化性质及改性作用研究进展

淀粉是谷物的主要成分。很多国家传统上都有不少发酵的谷物食品,如发酵米粉、发酵玉米食品等。近年来,不少研究人员针对发酵影响食品质构的机理、发酵对于食品成分的影响等方面进行了探讨。本文尝试对这方面的研究进行总结,分析发酵对淀粉的化学成分、分子结构、颗粒、糊化、老化、热学、凝胶特性、凝沉性、透明度等的影响,以期能够为这些传统食品的工业化等提供理论参考。     

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。     

挤压膨化对山药全粉理化性质、加工特性和淀粉体外消化性的影响

以山药全粉为原料,分析比较了其挤压膨化前后理化性质、加工特性和淀粉体外消化特性的变化.结果 表明,山药全粉经挤压膨化后,总淀粉、总脂肪含量分别从(67.80±0.01)％、(14.5±0.06)％下降到(65.47±0.01)％和(8.23±0.02)％,多酚和多糖含量分别增加了4.20％和38.38％,而可溶性蛋白、...     

荸荠淀粉的物化特性研究

以荸荠为原料提取淀粉,测定了淀粉的组成、颗粒及糊化、老化等方面的性质。结果表明,淀粉中直链含量为27．3％,淀粉颗粒为椭圆、多角等形貌,颗粒表面光滑平整,粒径为3～14μm,为接近A型的C型晶体。热力学参数分别为T064．08℃、Tp67．70℃、Tc72．85℃和ΔH11．97J／g干重。荸荠淀粉达到糊化温度后膨胀和溶解能力大于玉米淀粉、小于木薯淀粉,具有很高的黏性,透明度较好,抗冻融优良远高于木薯和玉米淀粉,但较易凝沉。     

冻藏处理对糯玉米淀粉微观结构和理化特性的影响

将新鲜糯玉米进行不同冻藏时间(0、10、20、30 d)的处理,通过傅里叶红外光谱仪、便携式拉曼光谱仪、X射线衍射仪、扫描电镜、差示扫描量热仪、快速黏度分析仪等研究冻藏处理对其内部淀粉微观结构和理化性能的影响规律,以期为延缓其品质劣变提供基础数据。结果表明：冻藏处理导致糯玉米淀粉的R_{1 045/1 022}减小,半峰宽增大,相对结晶度降低,淀粉颗粒表面出现凹陷和破碎,粒径变小,且随着冻藏时间的延长,冻藏对玉米淀粉微观结构的破坏更加明显;糯玉米经冻藏处理后,其淀粉的糊化温度、糊化焓值、峰值黏度、崩解值下降,最终黏度和回生值升高,表明冻藏淀粉更容易发生糊化,且糊化黏度降低,但淀粉热糊的稳定性有所提高,更容易发生老化。此外,冻藏处理还可导致玉米淀粉内的抗性淀粉和慢消化淀粉转变为快消化淀粉,表明冻藏具有提高鲜食玉米的消化速率和程度的潜力。