Cationic and Nonionic Starch Graft Polymers for Filler Retention

Graft co- and terpolymers were prepared by free radical polymerizations of vinyl monomers onto ω-irradiated starch by a prototype commercial process. Products with graft contents of up to 46%, by weight, were obtained by grafting acrylamide and quaternary amine-containing esters of methacrylic acid to starch. The graft polymers were evaluated on a pilot fourdrinier paper machine as filler retention aids and compared with several commercial flocculants. Drainage rate increased markedly with one of the starch graft terpolymers that was cationic. Since the number of starch graft polymers prepared was limited, the results reported, although excellent, are not necessarily optimal. Further studies are needed to establish the relationships of graft content and terpolymer compositions to retention and drainage.     

Degradation of Wheat Starch in a Single Screw Extruder: Characteristics of Extruded Starch Polymers

Wheat starch was processed in a 19 mm diameter, single screw extruder to study the physical and structural modifications that occur during extrusion cooking. Structural modification of the starch polymers was investigated using gel permeation chromatography (GPC), enzymatic digestions and dilute solution viscometry. Both the GPC and intrinsic viscosity results showed that the average molecular size significantly decreased as a result of extrusion processing. The relative amount of material excluded by Bio-Gel A150m was considerably lower for extruded samples than for unprocessed wheat starch and this size reduction of the amylopectin fraction was attributed to mechanical rupture of covalent bonds. The characterization of the structural modifications of the starch polymers is reported.     

Graft Copolymerization Onto Starch. 3: Grafting of Acrylamide Using Ceric Ion Initiation and Preparation of Its Hydrogels

The grafting of acrylamide (AM) onto maize starch in aqueous medium initiated by ceric ammonium nitrate (CAN) has been studied gravimetrically under nitrogen atmosphere. The effect of concentration of monomer and initiator, polymerization time and reaction temperature has been studied in terms of efficiency of grafting (%GE) and percentage Add-on (%Add-on). The %GE was found to decrease with increase in monomer concentration, but the reverse trend was obtained on increasing the polymerization time and temperature. The maximum %GE was obtained at 45°C when polymerization was carried out for 180 min using [CAN] = 0.004 mol/L and [AM] = 0.141 mol/L in 100 mL of distilled water with 2 g of starch. These graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. The graft copolymers showed enhanced thermal stability than pure starch. Hydrogels were prepared by grafting AM onto gelatinized maize starch followed by saponification of these graft copolymers with NaOH. The maximum water absorption obtained was 170 g/g.     

Reaction of Epichlorhydrin with Carbohydrate Polymers. Part II. Starch Reaction Mechanism and Physicochemical Properties of Modified Starch

Detailed mechanistic pathways are described for starch-epichlorohydrin (ECH) reaction. The mature and extent of side reactions accompanying the cross-linking reaction as well as the influence of reaction conditions on these have been demonstrated. The influence of degree of crosslinking of starch on its various physicochemical properties such as swelling, solubility, gelatinization, viscosity, iodine complex, crystallinity and granular structure are discussed.     

Graft Copolymerization of Acrylonitrile Onto Sodium Salt of Partially Carboxymethylated Starch Using Ce4+ Amine System as Redox Initiator

Graft copolymerization of acrylonitrile onto Sodium salt of partially carboxymethylated starch using ceric ammonium nitrate(CAN) has been carried out in the presence of triethylamine, diethylamine, ammonia and pyridine. The percentage of grafting varied with the nature and concentration of the amines. All the amines with exception of diethylamine have been found to suppress grafting. The relative reactivity of different amines towards grafting has been determined and found to follow the order: DEA > TEA > ammonia > pyridine.     

Reaction of Epichlorhydrin with Carbohydrate Polymers. Part I. Starch Reaction Kinetics

The starch-epichlorohydrin (ECH) reaction follows second order kinetics, first order with respect to ECH as well as starch. The activation energy for the reaction is of the order of 38 kJ/mole and the temperature coefficient K323/K303 is of the order of 2.     

Absorbent Polymers from Starch and Flour Through Graft Polymerization of Acrylonitrile and Comonomer Mixtures

Polyacrylonitrile (PAN)-containing graft copolymers of corn starch were prepared from monomer mixtures and then saponified, and dried. Incorporation of selected comonomers lead to shorter saponification times and higher yields of adsorbent products. Substitution of flour for starch gave products which had a higher absorbency than saponified starch-g-PAN.     

Starch Graft Polymers. II. Preparation of Graft Polymers Containing Acrylamide and Acrylic Acid and Evaluation as Textile Print Paste Thickeners

Graft copolymers of starch and the vinyl monomers acrylamide (I) and acrylic acid (II) – prepared by γ-radiation induced grafting reactions – and a graft terpolymer of starch, I and II – prepared by base hydrolysis of a graft copolymer of starch and acrylonitrile (III) — have been evaluated as textile print paste thickeners. Preparation, characterization and evaluation procedures are presented together with results illustrating that starch poly (I) containing 39% poly (I) and starch poly (I, II) containing a mixture of 21% I and 37% II are effective thickeners in this application if used in combination with one another or with commercial thickeners such as algin (sodium alginate).     

Sedimentation Field Flow Fractionation Combined with Multi Angle Laser Light Scattering Applied for Characterization of Starch Polymers

Sedimentation Field Flow Fractionation in combination with multi angle laser light scattering was applied to fully destructured potato and waxy corn starches to investigate the molecular weight and radius distributions of the starch components. In a range of radii betwen 50 and 500nm, information could be obtained about the influence of the medium conditions on the distributions. The averages of molecular weight and particle radius were found to decrease when holding the solution at a given temperature for an extended period of time (from 20min up to 60min) and when the temperature was increased (from 160°C up to 175°C). The molecular weight and radii of gyration of the dissolved starch species typically panged from 10⁶ to 10⁹ daltons and 50nm-500nm respectively. Changes in the distributions due to different conditions during the dissolution process where also recognized by changes in the shape of the distribution curve. Thus the applied technique gave satisfactory results in a high molecular weight region where SEC fails.     

淀粉氧化基本特征

淀粉化学品是一种有利于环保的绿色物质。概述了淀粉基本的化学和物理性质,根据需要可将淀粉改性为需要的氧化淀粉及衍生物。淀粉氧化后,得到羧基和羰基,描述了氧化淀粉表征参数及其在各行业中的应用。     

Gelatinization of Starch and Modified Starch

Gelatinization temperatures of starch and hydroxyethyl starch was determined using Differential Scanning Calorimetry (DSC), hot stage microscopy and viscography. The gelatinization temperature based on peak temperature of DSC is incorrect. Viscograph overestimates the gelatinization temperature. Hot stage microscopy based on visual observation gives the correct gelatinization temperature. DSC gives the heat of gelatinization which is helpful in estimating heat requirement during cooking of starch. Hydroxyethylation of starch reduces gelatinization temperature and heat of gelatinization for starch.     

Retrogradation of Starch Mixtures Containing Rice Starch

ABSTRACT: Different starches often coexist in food systems. Starch retrogradation is the primary reason for quality deterioration of a food system during storage. This article addresses the retrogradation behaviors of several starch mixtures containing normal rice starch (NRS). Potato starch, tapioca starch, waxy corn starch, hydroxypropylated potato starch, hydroxypropylated tapioca starch, and acetylated tapioca starch were mixed with NRS. Starch suspensions were gelatinized and the relative solid content, (S′) measured by pulsed nuclear magnetic resonance, was used to characterize the retrogradation behavior of starch systems. The retrogradation behaviors of starch mixtures can be divided into two categories according to the additive or non‐additive nature of S′, for which the concept “regional moisture content” was introduced.     

蕨根、葛根和马铃薯淀粉微波膨化加工性质的比较研究

研究了在蕨根淀粉、葛根淀粉和马铃薯淀粉中添加食盐、碳酸氢钠、蔗糖、油脂后微波加热效果、物料膨化效果的改变情况。结果表明:由于食盐、碳酸氢钠、蔗糖对淀粉糊化的影响及加热后的特性,随着添加量的增加膨化率变小,膨化过程也相对迟缓;随着糖含量的增加,产品的孔隙状态发生变化,孔隙变形、回缩,产品硬度减小,脆度增大,孔隙率渐大,色泽加深。油脂的添加,对脆度影响较大,但是对于膨化率、色泽的影响不大,添加过多时,口感变差。最佳配比是:食盐2%~4%,碳酸氢钠0.1%,蔗糖3%~6%,油脂3%~5%,并添加适量甜味剂以改善口感。     

Starch and Starch Derivatives Industry in India

Tapioca and maize are the major sources of starch in India. Tapioca starch is produced in very small units which are not extensively mechanized. This quality of the starch produced is not of a high quality. Maize starch is produced in mechanized units. The liberalization of the economy and growing consumerism bode well for the starch industry in India. Growth of the starch industry would depend on developing applications for starch as well as optimizing usage to derive maximum benefits. The unique properties of maize and tapioca should be considered.     

鹰嘴豆淀粉与红薯淀粉复配粉条的研制及工艺优化

纯鹰嘴豆淀粉制作的粉条韧性好,蒸煮过程中内容物溶出少,损失小,但其富含直链淀粉,不易糊化,且粉条透明度较差,故考虑添加含支链淀粉较多的红薯淀粉对其品质进行改善。通过单因素及正交试验,以感官评价为主,结合蒸煮损失、透光率等指标的测定,优化出最佳工艺参数。结果表明：当红薯淀粉添加量20%、含芡量10%、含水量44%、老化时长3 min 时,粉条的感官及烹煮品质最优;相比纯鹰嘴豆粉条,复配粉条更易糊化、光滑明亮、筋道可口,且不易糊汤与断条。     

用玉米淀粉制备交联淀粉的工艺

以玉米淀粉为原料,以柠檬酸和乙酸酐为交联剂制取交联淀粉,通过反复试验研究了不同混合酸的用量、不同混合酸比例、不同反应时间、不同反应温度条件对交联淀粉交联效果的影响,最后采用正交试验优化了制备交联淀粉的工艺条件,为制备交联淀粉提出了新工艺。     

Starch Graft Polymers. III. Preparation of Graft Polymers Containing Acrylamide,Acrylic Acid and β-Methacryloyloxyethyltrimethylammonium Monomethyl Sulfate and Evaluation as Flocculants for Bauxite Ore Red Mud Suspensions

Graft co- and terpolymers of starch and the vinyl monomers acrylamide (I), acrylic acid (II), acrylonitrile (III) and β-methacryloyloxyethyltrimethylammonium monomethyl sulfate (IV) were prepared and evaluated as flocculants for bauxite ore red mud suspensions. Starch-poly (III) was base hydrolyzed to starch poly (I, II) before evaluation. Products containing poly (I), (II), and (IV) were prepared by γ-radiation induced grafting while that containing poly (III) was prepared by ceric (Ce⁺¹⁴) ion initiated grafting. Preparation, characterization and evaluation procedures are presented together with results illustrating that starch poly (II) containing 38% poly (II) is an effective flocculant for domestic bauxite ore red mud suspensions.     

磷酸酯淀粉与醋酸酯淀粉性能对比

为探讨磷酸酯淀粉与醋酸酯淀粉性能及上浆效果的差异,对两种变性淀粉的浆膜、浆液性能进行了测试,分析了二者用于纯棉纱上浆效果的差异.结果表明:磷酸酯淀粉的浆液性能以及上浆效果均好于醋酸酯淀粉.     

变性淀粉让软糖口感更佳

<正>淀粉是一种供应稳定、价格低廉,广泛应用于食品工业的重要原材料。经过或长或短的改性过程,淀粉可以转变为多种衍生物,如变性淀粉。目前变性淀粉作为一种常用的食品添加剂,已经在乳制品、酱类、冷冻食品和糖果等食品中得到了广泛地应用,其中在凝胶糖果中变性淀粉的作用尤为明显。