Weizenstärkekörner. polarisationsoptisch und elektronenmikroskopisch

In earlier studies since 1961 [1] the author has observed that the A type starch granules of Wheat and other Hordeae show between crossed Nicols in most cases differentiated polarization crosses. In the center of these there is a little high double refracting disk with a small dark polarization cross. In the broader outer zone, which is not so bright, the armes of the small cross are persued much broader and indistinct. A. D. Evers (1971) has shown with the scanning electron microscope that the development of A type starch granules begins with an initial minute spherical granule, which becomes a „nucleus”︁, and which is progressively surrounded in the equatorial plane by a continually enlarging structure which resembles two lips with a furrow between them. When the lips have surrounded the „nucleus”︁ the thickness and diameter of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature biconvex structure only as a shallow score.     

In vitro Digestibility of Starch from Native and Germinated Pigeon Pea (Cajanus cajan L.)

The in vitro digestibility of native and germinated pigeon pea starches both in raw and cooked forms were investigated. The rate of digestibility (glucoamylase) was different for the two raw starches. There was a preferential utilization of low molecular weight ‘amyloses’ in the germinated samples, during in vitro enzymatic digestion of the raw granule. On acid hydrolyses, germinated samples produced lower molecular weight fragments than did raw starch, though the rate of reducing sugar released was not different. It may therefore be concluded that the size of the „amylopectin”︁ molecule is smaller in germinated starch. The easy availability of low molecular weight „amyloses”︁ may also influence the greater susceptibility of germinated starches to amylolysis even after cooking.     

Stärke als Chemierohstoff — Möglichkeiten und Grenzen

Starch as Raw Material for the Chemical Industry – Chances and Limits. As further, renewable raw material sources for the chemical industry are being opened up, starch may assume an important role. As a natural polymer capable of undergoing conversion and modification it could be adapted in a very flexible way to the requirements imposed on a product that is to be used as a raw material for biotechnical or chemical processes. There are different ways of including starch products in the production and/or processing of synthetic polymers which are explained here by reference to polyolefins, polyurethane foams and various condensation resins. By selective, preferably enzymatic conversion of the starch and by subsequent hydrogenation of the resulting mixtures of mono- di- or oligosaccharides it is possible to obtain a wide range of polyols. Anhydro compounds formed, for example from sorbitol, yield bicyclic polyols with the functionality 2 for which manifold outlets are certain to be found not only in polymer chemistry. The possible uses of starch as a chemical raw material which are described here, as well as other conceivable uses could be a serious contribution to a solution of raw material and energy problems.     

Isolation and characterization of the flour and starch of plantain bananas (Musa paradisiaca)

Plantain bananas of the variety “Terra” (Musa paradisiaca) may have industrial value due to their high starch content. In this research, the flour and starch of such unripe fruit were isolated and their chemical, physicochemical, and structural characteristics were determined. Banana flour and starch had a dry basis yield of 50.6 and 28.5%, and an average granule size of 31.7 and 47.3 µm, respectively. Both raw materials revealed a C‐type pattern and high gelatinization temperatures. The peak viscosity was greater for flour (378.0 RVU) than for starch (252.6 RVU), although the final viscosity was lower. At temperatures above 65°C, the swelling power of banana flour was lower than that of starch, while the solubility of flour was greater than that of starch at all temperatures. Furthermore, the presence of other components in banana flour influenced its physicochemical properties. In general, the flour and starch processed from unripe bananas have numerous possible uses as ingredients in food systems and for other industrial purposes.     

源于淀粉和纤维素替代材料的4类绿色环保餐具评价

为了比较源于淀粉和纤维素替代材料的环境绩效,以餐饮外卖领域推广使用的生物基餐具(复合淀粉基材料、覆膜纤维基材料)与可降解塑料餐具(全淀粉材料、全纤维材料)为研究对象,分析产品生命周期中的各种资源、能源消耗和环境排放并评价其环境影响。以1000个外卖食品餐盒为基准流,利用环境评估软件建立绿色环保餐具的生命周期评价LCA模型。结果表明,源于淀粉的绿色餐盒碳排放和能量消耗主要集中于原料获取和废弃物处理两个阶段,源于纤维的绿色餐盒碳排放和能量消耗则主要集中在制品生产阶段。全淀粉可降解餐具的各项环境影响指标最低,其中累计释放CO239.91kg,消耗电能332.04 MJ,较全纤维可降解餐盒碳排放降低69.5%,节约电能416.23 MJ。     

New Industrial Products from Starch

The industrial (non-food) use of starch and starch-based products as renewable raw materials is discussed together with examples, in the following application areas:

• –Starch as auxiliary raw material: binder, adhesive, thickener, protective colloid.
• –Starch as raw material for new products in chemical or biotechnical processes: polyols, acids, polysaccharides, enzymes.
• –Starch as filler with specific functionality for synthetic polymers to improve application properties in e. g. polyethylene, polypropylene, polystyrene, polyurethane-foams, styrene/butadiene copolymers, polyvinylchloride.
• –Starch as reactive component to be incorporated during production of synthetic polymers leading to synergistic effects: urea/formaldehyde resins, phenolic resins, alkyd- and melamine resins.
• –Starch-based active materials which either exhibit direct functionality themselves, (e. g. as surfactants, sequestrants and bleaching boosters) or which represent building blocks for the synthesis of chiral compounds for the pharmaceutical or the agro-industries.

     

Bedeutung der EG-Agrarmarktregelungen für die Stärkeindustrie

The Importance of the EEC Agricultural Market Regulations for the Starch Industry The role of starch, produced from annually renewable sources, as a raw material for the technochemical industry is increasingly being recognized. Intensive research efforts are made to expand the uses of starch products capable of partially replacing petrochemical raw materials in this area. If is necessary that the EEC creates the basic conditions enabling the starch industry to purchase the raw materials needed for this sector at world market prices. Taking account of this need the EEC Commission has worked out proposals for a reform of the starch regulations, which would restore the competitive balance of the EEC starch industry and their technochemical customer industries in relation to competitors from third countries. The starch derivative isoglucose, however, seems to remain a stepchild of the EEC regulations inasmuch as it is denied a development comparable to that on the sweetener market in USA. This situation is at variance with the advancement of biotechnology which the EEC itself considers desirable and whose aim it is to widen the uses of agricultural raw materials in the technochemical sector.     

Comparison of Enzymic Saccharification of Starch and Cellulose from Technological and Economic Aspects

Enzymatic saccharification of starch in the case of both pure starch and starchy raw materials is a long adopted technology successfully applied on industrial scale for many years. On the other hand, a feasible procedure for enzymatic saccharification of the other glucose polymer, cellulose, has been realized so far only on pilot-plant scale. A particularly difficult problem is the enzymatic saccharification of cellulosic substances encrusted with lignin. The first step in starch and cellulose saccharification is pretreatment and digestion of the raw material. In the case of starch, this is solved by liquefaction in the presence of thermostable alpha-amylase in a jet cooker. As a result, starch undergoes partial degradation and liquefaction. In the case of cellulose, the most economical method of pretreatment seems to be “steam-explosion”, although this does not involve liquefaction either, i. e., saccharification proceeds still in heterogeneous phase. Comparison is made of the energy requirements of digestion of the raw materials and costs of enzymatic saccharification for both substrates.     

The impact of treatment of cereal mashes with hydrolases of non‐starch polysaccharides and pullulanase on the chemical composition of the obtained distillates

The distilling industry has been looking for more efficient technologies for spirit production. The pressureless starch liberation method (PLS) is an energy‐saving alternative to high‐pressure treatment of starch raw materials. Also, one of the promising solutions is the use of supportive enzymatic preparations during the mashing of starch raw materials. Rye and corn mashes obtained by the PLS method were treated with enzymes (pullulanase, xylanase, cellulases and cellobiase). The composition of volatile compounds in the distillates of the fermentation mashes was determined. Acetaldehyde was the dominant aliphatic carbonyl compound found in the raw distillates. Rye‐based fermentation distillates contained small amounts of propionaldehyde, isobutyraldehyde and isovaleraldehyde, which were not found in any of the corn distillates. The treatment of mashes with cellulolytic preparations caused an increase in the methanol content of the obtained distillates. All of the mashes treated with auxiliary enzymes yielded raw distillates with much higher levels of higher alcohols. The application of hydrolases of non‐starch polysaccharides, or pullulanase preparations, during the mashing of the starch raw materials affects the chemical composition of the distillates. Xylanase and pullulanase can be used in the processing of rye and corn mashes for subsequent use in distilled ethanol beverage production. Copyright © 2014 The Institute of Brewing & Distilling     

Über die Kinetik der Amylolyse. Teil V. Untersuchung der SH-Gruppen der Weizen-beta-Amylase und Nachweis der induzierten Anpassung

In presence of substrate the inhibiting effect of thiol reagents is vastly decreasing. The enzyme molecule undergoes certain structural changes as a cause of „induced adaptation”︁, thus rendering the internal SH-groups inaccessible. Those free SH-groups on the surface play no significant role in the reaction catalyzed by the enzyme. On the Kinetics of Amylolysis. Part V. Examination of the SH-Groups of Wheat-β-Amylase — Proof of Induced Adaptation. During titration of wheat-β-amylase with p-chlorine mercury benzoate (pCMB) it was stated that the enzyme protein contains four sulfhydryl-groups (SH-groups) per molecule two of which are lying freely on the surface, whereas two are „hidden”︁. In absence of substrate thiol reagents instantly react with the SH-groups. pCMB and N-ethyl maleinimide cause an almost complete inhibition which is non-competitive in the case of pCMB as was demonstrated in reaction kinetic tests.     

纤维素水解液发酵生产氨基酸的研究进展

生物质是地球上最丰富的可再生资源,随着人类社会的快速发展,能源及资源危机日益凸现,开发和利用可再生资源已成为世界各国关注的热点,开展农业生物质资源转化研究也成为我国资源利用的重大基础和战略问题。中国是氨基酸的生产和消费大国,年总产量超过500万t。目前氨基酸发酵常采用玉米淀粉水解液作为碳源,拓展原料来源,寻找代替原料降低碳源成本,对氨基酸的成本构成决定性作用。该文主要介绍了我国生物质资源的现状,氨基酸的生产方法,重点论述了以纤维水解液生产氨基酸的研究进展及存在问题,为木质纤维素合理利用及氨基酸发展提供新的思路。     

Hafer,Gerste und Triticale — Eigenschaften und Chancen für die technische Stärkegewinnung

Oats, Barley and Triticale — Properties and Chances for the Industrial Starch Production. Process development for the recovery of novel materials from agriculture for chemical and technical utilization has become a main point in the research program „Renewable Resources”︁ of the Federal Ministry of Nutrition, Agriculture and Forestry. In preliminary investigations oats, barley and triticale were tested for the development of starch manufacturing processes. Cereal milling techniques and methods for separation of starch, protein and fibre were predominant with water extraction, screening and centrifugation techniques which can be realized in technical scale. Process water recycling, acid treatment and separation of proteins reduced COD values to 50%. Starches with high percentage of small granules will get more importance for the production of novel technical and chemical derivatives. Methods for concentration and isolation of fine fractions were studied and controlled by electron microscopy. The starches showed differences in stability to alkali treatment and in viscosity characteristics.     

Starch production and industrial use

This review of starch is concerned with its industrial uses, origins and structure. The current demand for starch is met by a restricted range of crops, the most important of which are potatoes, maize, wheat and tapioca. Improvements in the properties of starches for industrial uses can be achieved through chemical and physical modification of extracted starch and through the manipulation of starch biosynthesis in the plant itself. We examine starch structure and composition in relation to its use and exploitation by industry. The current understanding of physiological and biochemical mechanisms influencing starch formation in higher plants is described. This information is set in the context of the need to know the physical/chemical specification for each individual starch and to understand the genetic control of these characteristics in order to identify target genes for manipulation. © 1998 SCI.     

Entwicklung der Holzverwendung im 19., 20. und 21. Jahrhundert

Up to the 19th century wood was indispensable e.g. as fuel and raw material for construction, for domestic uses, in agriculture and all kinds of crafts, in shipbuilding and mechanical engineering etc. With the transition to the industrial era in the 19th century wood was displaced in many of its traditional uses by other raw materials such as coal and steel. In the second half of the 19th and in the present century, however, numerous new wood based products were developed, in particular with a view to making wood better adapted to the requirements of industrial uniformity. This was achieved by homogenizing wood properties and by becoming more independent of tree dimensions. Its versatility and the fact that it is the only and most abundantly growing environmentally beneficial and renewable material at our disposal is bound to increase the worldwide demand for wood in the 21st century in relation to the expected population explosion. Recent concern all over the world is centred on this issue whether we need more forests to sequester atmospheric C0₂. There can be no doubt that not only are more forests required for this purpose, but also that we - the foresters of the 20th century - cannot be released from the obligation to increase the availability of this invaluable and irreplaceable resource for future generations.     

Development of Starch Based Plastics - A Reexamination of Selected Polymer Systems in Historical Perspective

Recent patents in the starch-based plastics area have claimed melted or “destructurized” starch as a new type of material. The term “destructurized starch” has apparently been coined after the physically modified state of starch obtained by the disruption of the granular state, resulting in the loss of order and crystallinity. A brief literature review is presented which shows that, in the 1970's. starch containing low (10–30%) water contents was extruded at elevated temperatures to give a thermoplastic melt exhibiting no residual starch crystallinity. Differential scanning calorimetry studies of starch-g-polymethyl acrylate and blends of starch with poly (ethylene-co-acrylic acid) are also presented. These data indicate that these materials, prepared in the 1970's, also contain starch which was partially or completely destructurized. Thus, although ideas and uses for destructurized starch in plastic items have proliferated in recent years, completely melted or “destructurized” starch had been conceived and used much earlier.     

Wörterbuch „Stärke”︁. Teil 1

Vocabulary „Starch”︁. Part I. After comprehensive preliminary work by the Working Group „Terminology”︁ of the Technical Committee „Starch, Including Derivatives and By-Products”︁ of the International Standardization Organization ISO (WG 10, ISO/TC 193) a vocabulary of important terms of the starch chemistry and starch technology in English and French language was made available. G. Graefe reported in this journal from time to time about the state of this work [Starch/Stärke 16 (1964), 229-232 and 381 -385; 17 (1965), 263–268; 23 (1971), 103–111; 27 (1975), 56–61 and 131–134]. The second, and for the time being last amendment of the vocabulary was edited at 1. 6. 1979 as International Standard ISO 1227-1979 (E/F). In the following the collection of technical terms which exists corresponding to the ISO regulations only in English and French language is made available together with a non obligatory translation into the German language to a bigger community of interest.     

Physical and Mechanical Properties of Biobased Materials Starch,Polylactate and Polyhydroxybutyrate

Commercial and semi‐commercial biobased materials (Polylactate, PLA, polyhydroxy‐butyrate, PHB, wheat starch and corn starch) were investigated. Physical and mechanical characterisation (tensile strength, elongation, tear strength, compression, gas permeability (CO₂ and O₂) and water vapour permeability (WVP)) was examined. Tests on both films and cups show potential use of these materials for primary food packaging, especially PLA and PHB. An interesting O₂:CO₂ permeability ratio (1:7 to 1:12) was seen, which make these materials suitable for packaging of food with high respiration. The mechanical properties were comparable to conventional materials such as polyethylene (PE) and polystyrene (PS). The WVP measured on films ranged from 12.6 to 18.6 [g H₂O/(m² ? 24h)], and on cups the range was 2.2 to 10.5 [g H₂O ? 700 μm/(m² ? 24h)]. The WVP for the starch‐based materials seems to be the most crucial parameter, and needs improvement if these materials are to be used as food packaging.     

小麦粉破损淀粉含量对面团发酵性能的影响

以中、高筋小麦粉为研究对象,分析破损淀粉含量对面团流变发酵特性和馒头品质的影响。结果表明,随着破损淀粉含量增加,面团流变发酵性能、馒头比容、亮度及感官评分均先上升后降低;中、高筋小麦粉破损淀粉含量分别为25.11,25.60时,面团发酵高度、总产气量和持气率最大;制作的馒头比容、亮度大,感官评分最高,外形挺立、表面光滑、内部结构均匀细密、口感好。因此,中、高筋小麦粉破损淀粉含量分别为21.65~25.11,23.56~25.60时,馒头品质较好。