Lablab Bean Starch. I. Properties of its Granules and Pastes

The variety of lablab bean (Dolichos lablab) starch studied by the authors, presents smaller-sized, rounded granules, and others, larger ones, which are generally oval-shaped and measure up to 30 micra. These latter show 1, 2 or 3 polarization crosses under polarized light. The gelatinization temperature of the granules varies between 65–70–76 °C and iodine affinity shows a value of 6.05. Graphs were drawn for the swelling power, percentage of solubles, Brabender viscosity of the hot and cold pastes, and also for the observation of the effect of a-amylase on these pastes. It was observed that the starch pastes present the cross-linked type Brabender viscosity curves, which greatly resemble those of the chick pea, yellow pea and navy bean starches. Several theories relating to the composition and structure of the starch, and which might explain its behavior, were approached by the authors.     

板栗淀粉糊的特性研究

通过对板栗粉中占主要成分的淀粉的研究,为后期板栗粉冲剂开发提供试验理论依据,探讨了板栗淀粉糊的溶解度和膨润力、透明度、凝沉性、冻融稳定性以及凝胶强度等性质,并与小麦淀粉、玉米淀粉进行了比较。研究结果表明,从85℃开始,板粟淀粉的溶解度和膨润力都有很明显的上升;板栗淀粉的透明度低于小麦淀粉和玉米淀粉相似;凝沉现象随时间的增加比较明显;板栗淀粉的冻融稳定性和凝胶强度性质较其他两种淀粉出色。     

板栗淀粉糊特性的研究

探讨了板栗淀粉糊的透明度、凝沉性、冻融稳定性、流变性、抗剪切稳定性、触变性等性质 ,以期为板栗的深加工提供理论依据 ,促进板栗的发展     

10种淀粉的理化特性研究

通过对10种植物淀粉糊透明度、凝沉性、冻融性、流变性的理化特性研究,结果表明:薯类淀粉相对于其他类的淀粉糊具有更高的透明性、较低的凝沉比和黏度。加糖加盐对不同淀粉糊有不同的凝沉作用。相对于其他淀粉,玉米、糯米、高粱和小麦淀粉的析水率较低,有较好的冻融性。高粱淀粉、绿豆淀粉,马铃薯淀粉、藕粉淀粉、木薯淀粉黏度均随着剪切速率的增加而明显剪切稀化,呈典型的假塑性流体特性和具有触变性。高粱淀粉、绿豆淀粉有较高的黏性。高粱、小麦、糯米淀粉糊不耐酸性,而红薯、马铃薯、绿豆、藕粉、木薯淀粉糊相对来说比较耐酸性。所有类型的淀粉糊随着pH增加黏度有渐增趋势。     

4种马铃薯淀粉糊流变特性的研究

对4种不同加工方式获得的马铃薯淀粉糊流变特性进行了探讨。静态流变特性测定结果表明,4种淀粉糊的流变模型为幂率模型,均为假塑性流体,每种淀粉糊以相同方式流动需要施加的力不同。在相同流动方式下,淀粉4粘度最大,其次为淀粉2,淀粉1和淀粉3的粘度近似相同。动态流变特性测定结果表明:随着温度的增加,淀粉1、2、4的弹性模量、粘性模量刚开始基本不发生变化,到60℃后,两模量急剧增加到最大值,然后降低到某恒定值。淀粉3的两模量随温度升高逐渐增加到最大值,然后逐渐降低到某恒定值。粘性模量达到最大后,淀粉2的粘性模量最大,其次为淀粉4、淀粉1,淀粉3的最低。弹性模量达到最大后,淀粉4的弹性模量最大,其次为淀粉2、淀粉1,淀粉3最低。     

葛根淀粉颗粒性质的研究

本文对葛根淀粉颗粒的性质进行了研究，包括淀粉颗粒的大小、形貌、X—射线衍射图谱、α—淀粉酶的酶水解作用方式等，并与玉米淀粉进行了比较。结果表明：葛根淀粉平均粒度为24．08μm，小于玉米淀粉的38．97μm；葛根淀粉和玉米淀粉颗粒的偏光十字接近颗粒中心，但葛根淀粉颗粒的偏光十字不明显；葛根淀粉的X—射线衍射图谱为C型，玉米淀粉为A型，而两者的结晶度分别为18％和37％；葛根淀粉和玉米淀粉对α—淀粉酶的作用极为敏感，但在酶解方式上，葛根淀粉是在淀粉粒表面形成许多微孔并经脐心进入淀粉粒内部，而玉米淀粉则是被层层水解，在淀粉粒表面形成很少的微孔。     

莲子淀粉糊流变特性的研究

为探讨莲子淀粉糊及莲子淀粉-胶体体系的流变特性,使用流变仪研究了不同莲子淀粉乳浓度和添加不同亲水性胶体的莲子淀粉糊的流变特性。静态流变特性研究结果表明,莲子淀粉糊和添加胶体的莲子淀粉糊均为典型的非牛顿、时间依赖剪切变稀和触变性的流体,其流变特性曲线可用Herschel–Bulkley方程进行较好的拟合。随淀粉乳浓度和瓜尔豆胶(guar)、黄原胶(xan)添加量的增大,莲子淀粉糊的屈服应力τ0增大,而添加羧甲基纤维素(CMC)、卡拉胶(car)和海藻酸钠(alg)可使淀粉糊的流动性增强。动态流变特性研究结果表明,莲子淀粉糊储能模量(G')、损耗模量(G″)随莲子淀粉乳浓度增大而增大,且G'大于G″。添加CMC、alg能提高莲子淀粉糊的黏弹性,而添加guar和低浓度的xan、car则降低莲子淀粉糊的黏弹性。     

肇实淀粉糊特性的研究

对肇实淀粉糊的透明度、冻融稳定性、凝沉性、流变性、抗剪切稳定性、触变性以及不同条件如温度、pH值、NaCl和蔗糖等对肇实淀粉糊的影响进行了研究,以期为肇实淀粉的加工、应用提供一定的理论基础。     

Effects of Sodium Caseinate on the Rheological Properties of Starch Pastes

Effects of sodium caseinate on the rheological properties of starch-water pastes have been measured under steady shear conditions. In all cases a power law equation was found to describe the variation of viscosity with shear rate. The sodium caseinate increased the viscosity of the starch pastes and a starch-sodium caseinate synergistic effect occurred. Sodium caseinate caused the swollen starch particles in pastes to increase in volume. It is suggested that this is one of the factors responsible for the observed effects of sodium caseinate on rheological behavior.     

On the Mechanical Properties of Native Starch Granules

As a fundamental prerequisite for starch based material development, we set up a method to determine mechanical properties of native starch granules. Instead of measuring tiny single granules, we developed an indirect procedure. It relies on a verified composite material theory and simple tensile tests with starch filled plastics. Resulting data for native potato starch granules: elastic modulus 2.7 GPa, tensile strength 60 MPa, indentation hardness 113 N/mm². These data are similar to those of rigid thermoplastics.     

Effect of Octenylsuccinylation on Rheological Properties of Corn Starch Pastes

Rheological properties of corn starch octenylsuccinate (OSA starch) pastes (5%, w/w), at different 1‐octenylsuccinic anhydride (OSA) contents (0, 1.0, 1.5, 2.0 and 2.5%, w/w) were evaluated in steady and dynamic shear. The OSA starch pastes had high shear‐thinning behaviors and their flow behaviors were described by power law, Casson, and Herschel‐Bulkley models. Magnitudes of consistency index (K, K_h) and yield stress (σ_oc, σ_h) increased with the increase in OSA content and the decrease in temperature. Over the temperature range of 10–50°C, the effect of temperature on apparent viscosity (η_a,100) was described by the Arrhenius equation. The activation energy values (E_a = 10.7–13.9 kJ/mol) of OSA starches were lower than that (E_a = 15.9 kJ/mol) of native starch. Dynamic frequency sweep test showed that both storage modulus (G′) and loss modulus (G′′) of OSA starch pastes increased with the increase in OSA content. Dynamic (η^*) and steady shear (η_a) viscosities of OSA starch pastes at various OSA contents did not follow the Cox‐Merz superposition rule.     

Studies on Rye Starch Properties and Modification. Part I: Composition and Properties of Rye Starch Granules

Rye is considered as a potential raw material for starch industry. Starting from a survey of technical procedures of isolating starches from rye-flour and -grits investigations will be reported, which were performed on pilot plant- and laboratory-isolated rye starches. The present paper deals with its granule appearance and composition. A distribution of granule size between small granules (⩽ 10 μ − 15%) and large granules (⩾ 11 … ⩽ 40 μ − 85%) is typical for the totality of the starches. Differing distributions depend on the conditions of isolation: the entity of starch containing samples resulted from the laboratory procedures under investigation. Large-granule starch preparations were isolated in the pilot plant: the centrifuge-overflow contains the small-granule fraction which is high in impurities. Granule crystallinity amounts to 16%. The crystalline component - like in wheat and triticale starches - consists predominatly of A-polymorph - with up to 9% of the B-type. The isotherms of water exchange are of the cereal type. The contents of minor constituents largely relate to the small granule fraction which assembles the majority of crude protein, pentosans and lipids, which are difficult to remove

1 Large granule samples may be produced in high purity (⩽ 0,2% crude protein)

. Lipid components in all fractions influence the results of linear chain-iodine interactions and they must be removed to proceed from apparent to absolute polysac-charide indices. The absolute amylose contents amount to ∼ 25% for large granule samples and to 20–21% for small granule samples. The average chain-length of iodine binding helical regions was determined with 220–240 AGU.     

Some Properties and Degradability of Isolated Starch Granules

Starch granules of 11 starchy feedstuffs were isolated. An isolation procedure is presented. The procedure did not damage the starch granules, as could be proven by scanning electron microscopy. The starch granules were nearly completely defatted by the procedure and only about 0.5% of the original protein remained in the starch, except for rice starch. The content of apparent and real amylose was measured in the isolated starch granules. Degradability of raw materials and isolated starch granules was determined with α-amylase and rumen fluid. Starch of tapioca and rice was relatively easy to degrade by α-amylase and rumen fluid, while potato starch was relatively difficult to degrade by α-amylase. Starches containing a low amount of amylose were found to degrade faster than starches containing a high amount of amylose.     

Some Properties of Amaranthus paniculatas (Rajgeera) Starch Pastes

The lysine rich high protein seeds of A. paniculatas (Rajgeera) are reported to contain 50–60% of waxy starch, concentrated in the endosperm. However its food related properties are comparatively unknown. In the present work, paste viscosity, paste clarity, freeze-thaw stability and effect of shear on the viscosity of A. paniculatas starch paste have been studied and compared to corn starch. Also included are the stability of Rajgeera starch paste under pressure cooking (30 min, 15 lb pressure) and acidic conditions (pH 6.98—1.76). Rajgeera starch was found to have a higher paste viscosity, lower paste clarity and high freeze-thaw stability than corn starch. Both Rajgeera and corn starch underwent thinning on being subjected to mechanical shear. Rajgeera starch withstood pressure cooking conditions admirably, but was found to be sensitive to acidic conditions.     

Characterization of Pinhão Starch. Part I. Extraction and Properties of the Starch Granules

The starch fraction of Pinhão, the seeds of Pinheiro do Paraná (Araucaria angustifolia, Bert, O. Ktze) was easily extracted and represents 21.87% of total weight. The low content of protein, fat and ash accounts for the efficiency of the extraction and purification. Pinhão starch shows an amylose level and strong anionic characteristic similar to corn starch. The round-shaped granules are smaller than those of cassava and similarly resistent to DMSO solubilization, what suggests a very homogenous granular structure.     

Characterization of Pinhão Starch. Part II. Rheological Properties of the Pastes

Pinhão starch paste shows a viscoamylographic pattern that is not usual for cereal or tuber sources, being more closely related to leguminosae starches. The gel is highly resistant to heat and mechanical stirring and it shows a relatively low retrogradation. There is no peak viscosity and the gel is not easily cooked. The opacity is similar to that of cassava starch paste, when hot, and to that of corn, in cold conditions. Viscoelastic characteristics of the paste show a short-bodied behaviour, more similar to corn starch paste, although some elasticity may be clearly observed. The rheological properties of this starch make it a potential additive for blending with other starches, mainly for use in some processed acid foods submitted to cold storage.     

Effects of Storage on Dynamic Rheological Properties of Wheat Starch Pastes

The variation of the dynamic rigidities of wheat starch pastes during storage at various temperatures has been measured. The results suggest that a crystallization process is responsible for the observed increase in dynamic rigidity with time. The Avrami equation was used to interpret the results in an attempt to establish the mechanism of crystallization.     

Studies on the Biosynthesis of Starch Granules. Part 6. Properties of the Starch Granules of Normal Barley,and Barley with Starch of High Amylose-Content,During Growth

The granular morphology of two types of barley starch, widely different in amylose-content, has been investigated during the period of starch accumulation. The pattern by which the granules were laid down was markedly different, despite the previously observed similarities in the changes in the ratio and nature of the starch components.     

黄姜淀粉的基本性质研究

本实验运用电子显微镜、X-衍射、布拉本德黏度仪等分析仪器对黄姜淀粉颗粒形态、晶体结构、理化特性、糊化特性进行研究。结果表明:黄姜淀粉的颗粒表面光滑,平均粒径13.52μm,总淀粉含量73.4%,其中直链淀粉为23.6%。