Stärkekörner im Pflanzenreich Mikroskopische und submikroskopische Morphologie und Evolution

Starch Granules in Vegetation. Microscopic and Submicroscopic Morphology and Evolution According to the reaction in polarized light and by the fractionated swelling in water preparations by heating the starch granules show a clear submicroscopic reaction without evidence about the chemism of the starches. In some plant tribes the starch grains of seeds show different Basic Construction Types (BC-Types) as in the vegetative organs. Some Euphorbiaceae e. g. form rod-shaped starch granules in the nonarticulated lacticifers whilst the adjacent parenchyma cells contain round envelope starch granules. Most of the Pteridophyta, Coniferophyta, Ginkgo, Chlamydospermae and primary Monocotyledons show the so-called Pteridophyta Bas. Constr. Types, resulting from different but unknown behaviour. The multiplicity of starch granules is not only to explain by the polymer carbohydrates, length of chains, ramification and so forth but by the cooperation of “internal” substances of the starch granules from the substratum formed by the amyloplasts. In the Monocotyledons and Dicotyledons exists an increasing tendency to substitute starch granules by other storage substances.     

Zusammenhang zwischen Stärkegehalt und Dichte von Weizenstärkemilch

Connection between Starch Content and Density of Wheat Starch Slurry. Various starch suspensions were produced from pure wheat starch and water and respective specific weights of the starch concentrations were determined. For effective control of the different starch concentrations four dry matter analyses for each suspension were carried out. Weight percentages of the starch suspensions were converted into their respective density, Balling grades and Baumé grades and compiled in tables.     

Untersuchungen über die Retroaradation der Stärke in konzentrierten Weizenstärkegelen. Einfluß von Stärkeabbauprodukten auf die Retrogradation der Stärke

Investigations on the Retrogradation in Concentrated Wheat Starch Gels. Part 2. Effect of Starch Degradation Products on the Starch Retrogradation . In the present work the influence of added starch degradation products on the rigidity and retrogradation of 50% wheat starch gels was investigated. The gels prepared with the addition of maltodextrin were extracted with 40% ethanol, the extracts were analysed for glucose oligomers. The effect of the added starch degradation products was dependent on the degree of degradation. Weakly degraded, acid modified starches take part in the retrogradation process as do white and yellow dextrins as well as maltodextrins with dextrose equivalents (DE) <30. Maltodextrins and glucose sirups with a DE ≧ 30 act as plasticizers: in concentrations of 5-30% (based on starch d. s.) they reduce gel strength without affecting the retrogradation velocity. The plasticizing effects are particularly evident with maltose and maltotriose as well as maltotetraose and pentaose. Even so the extractibility of oligomers with a degree of polymerisation (DP) ≥ 6 was reduced, the hexamer and octamer might still have a plasticizer effect. With glucose, concentrations ≥ 26% were needed to observe plasticizing. The relation of these findings to bread staling is discussed.     

Radiolyse von Stärke Beitrag zur quantitativen Bestimmung einiger Radiolyseprodukte in Kartoffelstärke und Weizenmehl

Radiolysis of Starch. A Contribution to Quantitative Determination of Several Radiolysis Products in Potato Starch and Wheat Flour . The amounts of formed desoxy-compounds, which produce malonic dialdehyde during HI O₄-oxydation, as well as that of ω-hydroxymaltol have been determined in irradiated potato starch and irradiated wheat flour in dependence on irradiation doses. With pure potato starch, G-values*) of 0.03–0.04 for water soluble desoxy-compounds and such ones of 0.02 for insoluble desoxy-compounds were obtained. G-values of desoxy-compounds in an ethyl acetate-acetone-water extract (4: 5: 1 v/v) of irradiated potato starch and irradiated wheat flour showed a ratio of about 3: 1. When aqueous potato starch sols are irradiated desoxygroups in the high-molecular starch molecule will also be found (in N₂O atmosphere: G-values around 0.3). With ω-hydroxymaltol it became apparent that the main part of this compound is formed after irradiation during storage. With pure potato starch G-values around 0.015–0.02 were determined after 10 days of storage. When this material is heated after irradiation an increase of the hydroxymaltol content (G-values: 0.025) is to be found. In the non-irradiated materials traces of desoxy-compounds as well as ω-hydroxymaltol were found.     

Dynamische Entwicklung der Stärkeforschung und Stärkeindustrie in Japan

Dynamic Development of Starch Research and Starch Industry in Japan Refering to two lectures and visiting tours throughout Japan in 1962 and 1978 the dynamic development is indicated which has taken place in the Japanese starch research and Japanese starch industries within the past 16 years. In this connection the annual production figures as well as the most important field of applications for white potato, sweet potato, corn, and wheat starches are reported. Correspondent data are also made for starch saccharification products, whereat particular consideration is directed to the industrial production and marketing of high fructose syrup. As far as the starch research is concerned, the tremendous investments are emphasized which recently have been increased to a considerable extent. In this connection it is concluded that the remarkable progress which has taken place in both the Japanese starch research and Japanese starch industries obviously are based on two main factors. One of these two factors seems to be the almost unlimited financial possibilities of both government and industries, whereas the other one is connected with the extremely expressed working discipline of the Japanese employees. The great progress gained by the Japanese starch research as well as by the Japanese starch industries particularly within the past decade are not only very impressing, but at the same time also rather depressing with regard to the limited possibilities in the Federal Republic of Germany.     

Erfahrungen mit der NIR-Reflexionsspektroskopie bei der Routine-Analyse von Stärken,Stärkederivaten und Stärkeverzuckerungsprodukten

Experiences with NIR-Reflectance Spectroscopy in Routine Analysis of Starches, Starch Derivatives and Starch Saccharification Products . Application of reflectance-techniques in the Near Infrared is possible without any sample pretreatment in most cases. For routine-use the development of microcomputers was necessary because no distinct absorptions are measured between 900 and 2 500 nm. Therefore identification of absorption bands is rather complicated. A new generation of instruments based on this principle enables a rapid analysis of many products consisting of several components. The electronically stored calibration curves are activated by pressing a push-button and the instrument is ready for the next sample. Analysis time including sampling is one minute. Experiences with this technique in analysis of corn, starches, starch derivatives and starch saccharification products as well as their components water, protein, starch, and degree of substitution (acetate, hydroxypropyl, cyanoethyl, cationic groups) and degree of degradation (dextrose-equivalent, carbonyl and carboxyl groups) are given in the lecture. Broad application is possible because of the flexibility of this technique. Simple handling is important for use by untrained people. Estimated pay-back-period therefore is one year at maximum.     

Charakteristik der Stärke ausgewählter Kartoffelsorten Teil 1. Änderung des Stärkegehalts und der Stärkekorngröße während der Lagerung

Characteristics of Starch of Selected Potato Varieties. Part 1. Change of Starch Content and Starch Granule Size During Storage . Selected varieties of potatoes of the Czechoslovakian assortment were tested as to their contents of dry matter and starch, as well as to quality of their starch in three-years storage tests. Potatoes were stored in airconditioned boxes at temperatures of + 2 and + 10 °C. Analyses were carried out after harvesting and after storage. It was found that the content of dry matter was higher near the end of storage time. This increase was depending on temperature. Yet, related to dry matter the starch content had not diminished near the end of storage time. During storage of potatoes changes in the share of individual starch granule sizes do also occur. Larger granules were degraded to smaller ones, thereby increasing the latter's share. Higher temperature would also lead to an increase in these changes. The tests were supposed to show, wether during potato storage a change in size of starch granules takes place, and wether storage temperature may influence this change. Work on this problem will be continued.     

Chemische Modifizierung der Stärkeoberfläche. Einbau von Stärke in kovalente und thermoreversible Netzwerke aus synthetischen Polymeren

Chemical Modification of the Surface of the Starch Granule. Incorporation of Starch into Covalent and Thermoreversible Networks of Synthetik Polymers. In order to find a new field of application for starch, methods have been investigated to improve the compatibility of starch with synthetic polymers. Preparative steps are described which allow a dense layering of synthetic chains via urethan linkage at the surface of the starch grain without any loss of its structure. The properties of products coated with poly (oxyethylene) of different chain lengths were studied as to their suitability for being part of a thermoreversible network. Another set of experiments deals with starch being part of a covalent network of synthetic polymers.     

Untersuchungen über die Retrogradation der Stärke in konzentrierten Weizenstärkegelen. Teil 1. Herstellung konzentrierter Gele,Einfluß der Stärkekonzentration und Herstellungsbedingungen auf die Retrogradation der Stärke

Investigations on the Retrogradation in Concentrated Wheat Starch Gels. Part 1. Preparation of Concentrated Gels, Influence of the Starch Concentration and Conditions of Preparation on the Starch Retrogradation . A method for the preparation of homogenous, concentrated wheat starch gels is described. The influence of the starch concentration and conditions of gel preparation has been investigated by determination of gel strength (Avrami-analysis) and solubilized starch. An increase in starch concentration from 40 to 55% caused a corresponding increase in gel strength of the fresh gels, an enhanced increase in gel strength during storage and a reduction of soluble starch. The time of heating during gel preparation had little influence on retrogradation. The influence of the temperature of heating (130° and 100°C) was dependent on the starch concentration: with 40 and 50% gels a strong increase in water soluble starch is observed with the higher temperature, whereas the gel strength is increased with the 50% gels only. The amylose content in the gel extracts shows that both starch fractions take place in retrogradation. The water binding capacity of the insoluble starch is decreased during storage demonstrating that the retrogradation also occurs in the insoluble starch and significantly contributes to the increase in gel strength. Retrogradation in concentrated starch gels therefore proceeds inside and on the surface of the swollen starch granules as well as in the solubilized starch leached out during the heating process.     

Anisotrope Lichtstreuung durch eine Anhäufung von Stärkekörnern

Anisotropic Light Scattering by a Population of Starch Granules The problem of correlation between the “experimental” scattering diameters calculated using the Stein-Rhodes equation and the observed radii of single starch granules was reexamined for wheat and tapioca starches. The calculated “experimental” scattering diameter was compared with a “theoretical” scattering diameter calculated from an intensity profile which was computed by applying the Stein-Rhodes equation to the population size distribution. The agreement between these two parameters suggests that it is unnecessary to postulate an isotropic region in the centre of the granule.     

Die Stärkekörner der Kartoffelpflanze im Laufe ihrer Individualentwicklung

Starch Granules of the Potato Plant in the Course of Their Individual Development. Starch granules of the storage tubers of potato plants – small granules (⊘ up to 20 μm), normal granules (⊘ 21 to 40 μm), and large granules (⊘ 41 μm and more) – are typical storage starch granules, which have been greatly influenced by breeding and long cultivation of the potato plant, contrary to those starch granules to be found in the stalks (supplying and leading off). This fact becomes apparent especially in the swelling pattern and polarisation optical analyses. Starch granules over 41 μm frequently show extreme disorders in their typical structure, i.e. their crystalline structure as well as their layers. These starch granules frequently show cracks or branched fissures causing them to fall to pieces. These observations may lead to the conclusion that attempts to increase granule size in order to produce even larger granules of solid structure have hardly any prospect of success using the currently available methods such as selection and fertilization.     

Einsatzmöglichkeiten nicht backfähiger Weizensorten in der Stärkeindustrie

Application Possibilities of None-baking Wheat Varieties in Starch Industries . In search of possibilities to utilize none-baking wheat varieties which are marketed with increasing tendency particular attention was directed to the question whether these varieties can be used as source material in starch industries. At the begin of the investigations the behaviour of five wheat varieties was studied during the washing procedure of their doughs after the traditional and world-wide applied Martin process. Beside the Martin process also other technical procedure fo the manufacture of wheat starch have been taken into consideration which also are based on wheat flout as source material. However, preferably technical procedures were applied which are based on unmilled wheat as source material.     

Schweflige Säure und Stärkehydrolyse

Sulfurous Acid and Technical Hydrolysis of Starch. The decrease of SO₂ content which can be observed during the storage of starch sirups is not only based on simple oxidation to sulfate but also on the formation of different organic sulfur compounds. The reaction possibilities for SO₂ in technically produced hydrolysates are greater than in pure sugar solutions because of the presence of colored materials, their precursors and amino nitrogen containing compounds. Thus, the amount of analytically ascertained SO₂ content is not a satisfactory criterion for the purity of starch sirups. The proposed modification of the starch hydrolysis process by using SO₂ in the starch slurry gives a chance to eliminate the formed sulfur compounds extensively. Furthermore the products manufactured in this way show less tendency to discoloration, and higher storage stability especially with increased temperatures.     

Entwicklungstendenzen in der Stärke- und Zuckerindustrie in Abhängigkeit vom Rohstoff Teil 5. Zuckerrübe

Development Trends in Starch and Sugar Industries Depending on the Source Material. Part 5. Sugar-beet Performance and competitive power of the sugar-beet as base of the sugar-industry are described with regard to field productivity, energy value and labour requirement. In some respects the plant is compared with the most important starch delivering plants (potato, wheat, maize). Positive secondary effects of sugar-beet growing on land and field management are shown as essentially contributing to the further development and stabilization of the linked economy of the sugar-beet growing farm and the sugar-factory.     

Diffusion von Wasser in Stärkegelen

Diffusion of Water in Starch Gels. By the technique of NMR with pulsed field gradients we have studied the diffusion of water in maize starch gels with 50–95% H₂O at temperatures between 1 and 47°C. The water molecules showed uniform and unrestricted diffusion of the same activation energy as in bulk water. The coeffizient of self-diffusion D_s is roughly proportional to the square of the fraction of water and fits continuously to that of bulk water; D_S (gel)∼D_S (H₂O) ∼ (fraction of water)² The boundaries of the swollen starch grains are no barriers to diffusion.     

Thermisch modifizierte Stärke als Substrat für die Stärkeverzuckerung mittels Glucoamylase

Thermally Modified Starch as a Substrate for Saccharification of Starch to Glucose by Means of Glucoamylase. The thermal modification of starch was effectuated by rapid heating up to about 200 °C and subsequent rapid cooling. This process was carried out in a pneumatic apparatus. As a result of the thermal procedure a swollen starch was obtained which is capable to gelatinize at room temperature. The viscosity of the gel prepared from swollen starch is considerable lower than the viscosity of native starch, and the gel is a good substrate for Saccharification to glucose by means of glucoamylase.     

Untersuchung gefriergetrockneter Stärkekleister und Stärkeschwämme im Rasterelektronenmikroskop

Examination of Freeze-Dried Starch Pastes and Starch Sponges by Means of Scanning Electron Microscope. Pastes of potato and corn starch as well as various starch derivatives were examined by means of scanning electron microscope (SEM). As preparation method freeze fixation followed by freeze-drying were used. Special attention was directed to changes occuring in pastes after slow freezing and defrosting. Sample preparation which is more complex for the SEM than for light microscope has the advantage of its picture giving more accurate information on paste structure than those obtained by light microscopy. On the one hand, tests confirm results obtained by other authors on the structure of starch pastes by means of light microscopic photography, furthermore, new information was gathered especially regarding non-frozen pastes and pastes of starch derivatives. Illustrations of starch sponges as obtained by means of SEM are far more expressive than those obtained by conventional methods.     

Auswirkungen einer Feuchtkonservierung von Mais auf die Stärkequalität

Effect of Wet-Conservation Technique of Corn on Starch Quality. A corn starch production by German corn is practicable with reservation. Since the moisture content of the cernels varies between 30 and 40% instead of drying two wet conservation techniques were tested. With the experiments of using sodium hydrogensulfite no remarkable differences of quality criteria in comparison with non stored reference starches were observed along with the storage about 24 weeks. The ensiling of corn-cob-mix by a lactic acid fermentation resulted in starches of high quality, too. Consequently these two kinds of wet conservation techniques of storage are suitable in the same manner for starch production.     

Charakteristik der Stärke ausgewählter Kartoffelsorten Teil 2. Gehalt an Phosphor,Kalium und Calcium in der Stärke

Characteristics of Starch of Selected Potato Varieties. Part 2. Phosphorus, Potassium and Calcium Content in the Starch . It was found that during storage of potatoes not only changes in starch content and size of the starch granules do occur, but also changes in phosphorus, potassium and calcium content in the starch. The potassium content decreases during storage as a function of temperature. The phosphorus content decreases at +2°C and increases at +10°C. The calcium content increases in the final stage of storage. The phosphorus content in the starch decreases during storage. These results are of special significance with a view to preservation of starch quality.