Zur Differenzierung und Systematisierung der Stärkekörner

On the Differentiation and Systematics of Starch Granules . The possibilities of differentiation and systematization of starch granules by using microscopical methods have been reported. It was shown that their shape and size as well as their physico-chemical properties, i. e. swelling range and appearance in polarized light, could serve as characteristics for definite plant families or sorts respectively. A corresponding proposal for differentiation and systematization is presented and discussed.     

Zur Mikroskopie der Stärkekörner von gekeimten Kartoffeln

On the Microscopy of Starch Granules of Germinated Potatoes. Microscopic examinations of normally germinated as well as germinated and dried potato tubers and of the germs as such showed that the generalized assertion of D. Grebel, according to which a “melting” should be characteristical for the fermentative degradation (germination) of starch, cannot be confirmed. Indeed, the described melting phenomena occurred with single starch granules, the majority of the fermentatively deformed starch granules, however, showed the typical changes (channel formation) as they are to be seen with starch granules of cereals. With partially dried potato tubers and their germs the starch granules showed changes like those occurring with curcuma starch. Factors that are responsible for this symptom are being discussed.     

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.     

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.     

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.     

Der fermentative Abbau der Kartoffelstärkekörner

The Fermentative Degradation of Potato Starch Granules. The difference between the fermentation of the starch granules as a whole in the living cells during germination of the potato tuber and the enzymatic destruction of the isolated starch granules by microorganisms (bacteria or fungi) is once more demonstrated. The last named process results by setting pores or little channels into the substance of the starch granules or following the weaker zones of the sheaths.     

Einfluß organischer Düngung auf die Größe der Stärkekörner von Kartoffeln

Effect of Organic Fertilizers on Size of Starch Granules of Potatoes . The influence of cattle faecal matter combined with mineral fertilizers on tuber crop, dry substance content, yield and content of starch, and starch quality of potatoes was studied. From technological point of view for production of starch potatoes with high tuber yield and responding starch content all variations consisting of cattle faecal matter with addition of N, P, K proved to be favourable. The best combination was that of straw and cattle faecal matter with added N, P, K-fertilizers. Problems concerning the selection of the most favourable variation are discussed.     

Kritische Untersuchungen über Bildung und Entwicklung der Triticeen-Stärkekörner

Critical Examination of the Development of Triticeae Starch Grains. At the right time when the first antheres appear at the top of the ears large quantities of point-shaped starch grains are to be seen in the young ovary. From there the diameters of the small starch grains have been measured until milky maturity. In this way the identity and the growing of the small starch grains had been confirmed. After some days when diameters of the small starch grains reach 4–6 üm a second step of development begins. The starch grains are progressively surrounded in the equatorial planes by a consurrounded continually enlarging structure which resembles two lips with a furrow between them. When the two lips surround the „nucleus”︁ thickness and diameters of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature beconvex structure only as a shallow score.     

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.     

Beitrag zur Kenntnis der Verteilung von Amylose und Amylopektin in Stärkekörnern

Contribution to the Knowledge on Distribution of Amylose and Amylopectin in Starch Granules. Dialdehyde starch which has been reacted with thiosemicarbazide shows a simultaneous effect of fixation and contrast formation only after subsequent treatment with silver nitrate. Fixation is attributed to formation of interchenar acetal bonds promoted by liberated protons. These bonds appear primarily in the tighter packed and thus less oxidized, noncrystalline structural regions of starch. During treatment of the ultra thin sections in OsO₄ and steam at temperatures between 50–60°C the acetal bonds undergo reversible splitting with the liberated aldehyde groups reacting spontaneously with OsO₄. In such sections radially oriented fibrillar structures can be observed. In the amorphous regions, however, the fine structure of amylose is already destroyed during periodate oxidation and degradation products form microfine precipitates contrasted by silver. The crystalline fraction of amylopectin can be demonstrated electron-microscopically by poststaining with PWS (phosphotungstic acid). The study of structural modifications occuring in starch granules in the course of dough processing is given as an example of the application of this technique.     

Bestimmung des Gehaltes an Stärkekörnern gleichen spez. Gewichts und gleicher Größe

Determination of Starch Granules of Same Specific Gravity and Size. Several methods for determination and fractionation of starch granules of different size and specific weight were investigated. The most suitable method consisted in fractionation of the starch with respect to its specific weight by means of a centrifuge. The resulting fractions are investigated colorimitrically to determine their content of starch granules of different size.     

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.     

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.     

Modifizierte Stärken als Bestandteile von Lebensmitteln

Modified Starches as Ingredients of Food. During the past ten years the starch industry has made considerable progress in the improvement of the properties of modified food starches. Modified starches with a relatively low degree of substitution were found to have certain properties valuable to modern food technology which are not present in native starches. To prove that they are safe and pose no hazards to health the experts of the european starch industry in a yoint effort prepared for the Joint FAO/WHO Expert Committee on Food Additives (JEC) comprehensive monographies on modified food starches which are of particular interest to food manufacturers. On the basis of the biological and toxicological findings obtained from these tests, the JEC recently announced for all major modified food starches that they are toxicologically safe and may be used in foods without limitation by ADI values and without quantity restrictions.     

Die Hochdruck-Flüssigkeitschromatographie als Methode zur Untersuchung von Stärkehydrolysaten

High Pressure Liquid Chromatography as Method for the Analysis of Starch Hydrolysates . After a brief discussion of the principles underlying high pressure liquid chromatography, the possibilities of the method for a quantitative analysis of the sugar composition of starch hydrolyzates are explained. By reference to the results of serial analyses, accuracy and reproducibility as well as the time required with the method are outlined.