Der Energieaufwand in der Auswasch- und Raffinationsstufe bei der Kartoffelstärkefabrikation

Energy Demand for Extraction and Raffination Step in Production of Potato Starch. Results from the investigation of the energy demand of extraction and raffination step in production of potato starch are reported. On the basis of technological data as well as the energy demand optimum loads for extraction and raffination equipments which are now used in the polish potato starch industry were determined.     

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.     

Die Bedeutung der Schaumzerstörung bei der Kartoffelstärkegewinnung

The Significance of Foam Destruction for Potato Starch Production. During the production of potato starch destruction of the foam is inevitable at all stages of the process as it will interfere with the recirculation of the processing waters. This also affects the reduction of water consumption (related to the amount of raw material). The application of mechanical means or vapor for foam destruction is limited. Application of defoaming materials with simultaneous recirculation of floating and washing waters, two-step separation of the fruit juice and rendering innocuous of the starch waste waters by activation has proved to be the most advantageous process.     

Unschädlichmachung der Abwässer durch bessere Ausnutzung des Rohstoffes bei der Kartoffelstärkeerzeugung

Neutralization of Waste Waters by Better Exploitation of Raw Material During Production of Potato Starch . Neutralization of fruit juice set free during the production of potato starch can be carried out efficiently in two steps. The first step is based upon the coagulation of protein at 85 °C in acidify medium. The first step of methane fermentation, which is the acid fermentation, is made use of for this process. At this step mainly heterogeneous lactic acid fermentation takes place. Coagulated protein may be efficiently processed into feed thus making the purification of waste water more profitable. The second step is the methane fermentation as such. Considering the concentration of fruit juice from the separators a maximum load of the fermentation tank of 1.5 kg/m³ of organic matter has to be taken in account. At a higher load the period of fermentation is shortened to an extent that makes anaerobic processes impossible. During fermentation 15.25 m³ of fermentation gas per m³ raw water with a methane content of 54% are produced. This amount of gas should be sufficient for heating of the waste water up to a temperature which is necessary for caogulation. The fermentation of fruit juice has to be succeeded by a one-hour period of sedimentation of the mud. Thus, purification is made more effective. With this system the concentration of the fruit juice decreases to an extent which makes it possible to purify it further together with the processing water in a biological activation filter plant.     

Das Verhalten der beiden chromatographisch trennbaren Amyloseanteile bei der oxydativen Behandlung von Kartoffelstärke

The Behaviour of the two Separable Amylose Components during Oxidative Treatment of Potato Starch. During oxidative degradation of potato starch by means of sodium persulphate changes in both column and paper chromatography of the components amylose and amylopectin were proved. The fact that in the paper chromatogram one amylose component is degraded to a higher dextrine with a second amylose component as intermediate product has been proved.     

Bewertung der Eigenschaften von Kartoffelstärken

Evaluation of Potato Starch Properties . Different potato starches were studied by determination of their consistency curves with a Brabender viscosigraph, their absolute viscosity values and the ranges of swelling temperatures of the starch grains. Gradual elution analyses for comparison were carried out, and a simple potentiometric method was introduced in order to determine the average number of molecular weights M_n. Between different potato starches essential differences of the physical and colloidalchemical properties could be revealed in spite of the fact that their quality corresponded to didacted standards. The physical and colloidal-chemical changes of the starches may be ascribed to prolonged or inadequate storage. At the evaluation of the starch qualities the existing standards are no longer satisfactory. The starches should be classified especially by viscographic measurements and determinations of the average number of molecular weigths.     

Möglichkeiten und Vorteile der Vakuumreibe in der Kartoffelstärkeindustrie

Possibilities and Advantages of Vacuum Rasp in Potato Starch Industry When rasping potatoes the impact of air causes oxidation and as a consequence undesired discolorization of potato protein and pulp. Therefore, sulphur dioxide or sulphites are usually added during processing. An alternative solution seems to be rasping of potatoes in an oxygen-free system. The new procedure consists basically of an adequate infeed, a circulation system and a gas-tight rasp with discharge. The potatoes are fed by a water stream through an U-formed tube and via dewatering grid into the vacuum chamber of the rasp. Due to the difference in atmospheric pressure the mixture flows spontaniously into the rasp casing, so a pump is not required. The vacuum has a favorable influence on the noise-level of the rasp and on the protein quality.     

Über die Phosphorsäure der Kartoffelstärke

On the Phoshoric Acid in Potato Starch. Potato starch contains chemically linked ortho-phosphoric acid (30 to 175 mg% P). Among the physico-chemical properties of potato starch effected by the phosphoric acid the most important are ion exchange and selfhydrolysis. By the ability of ion exchange it is possible to produce the salts of the pure esters of amylo-phosphoric acid (cationic starches). Sodium, potassium, ammonium, calcium and magnesium starches differ in rheological properties. The hydrogen ions of amylophosphoric acid are able to effect the hydrolytic splitting of the starch. This hydrolysis consists of two different processes: the splitting of the glucosidic linkages and the splitting of the ester linkage between the phosphoric acid and the glucose unit. Velocity of self-hydrolysis is dependent on the hydrogen ion concentration. The self-hydrolysis of hydrogen starch offers the possibility of producing degraded starch products with different technical properties without any addition of chemicals and/or enzymes.     

Der Einsatz von Stärke bei der Modifizierung synthetischer Kunststoffe

Native Starch Used for Modification of Synthetic Polymers . Newcompounds were developed by modifiying synthetic polymers with starches. The resulting property profiles allow applications which are not accessible for the initial materials. Three different categories of compounds were produced by use of a corotating, intermeshing twin screw extruder and characterized with regard to their physical and mechanical properties. The first category includes materials which contain starch in their native grain form as a functional filler. The property profile depends on the interaction between the starch surface and the matrixpolymer. which can be improved by an organosilane coating. The two other categories are based on destructurized starch. The starch is modified in the twin-screw kneader by a thermo-mechanical desintegration of the macroscopic starch granules and under the addition of plasticising and softening agents. The created thermoplastically processable moulding compounds can be used directly as a material for special applications. However the more important application of such thermoplastic starches (TPS) is all area of blending or alloying with synthetic polymers. In combination with ethylencopolymers, compounds are obtained, in which TPS forms the disperse phase. Despite of its higher content in the blend, the TPS is embedded in the synthetic polymer matrix, forming small and discrete distributed particles. The resulting mincrostructure and morphology strongly affects the properties of the blends.     

Der Verlauf des Stärkeabbaues bei der Mälzung und während des Maischens in der Bierbrauerei

The Course of Starch Degradation During Malting and Mashing in the Brewery . The photometric iodine titration method was successfully applied to examine starch degradation during malting and mashing in the brewery. By this method the apparent degree of degradation as well as the changes in heterodispersity corresponding to the respective molecular weight of the starch were determined. During germination of the barley heterodispersity of starch changes but slightly. Starch degradation takes place mainly during the preparation of the malt mash. In the final part of the amylolytic period only a small amount of non degraded starch remains in the draff. During enzymatic mashing the characteristic values of the malt mash are not reached till in the last periods of the mashing process. Total degradation takes place only after swelling and gelatinization. This can be attributed to the different effect of the added α-amylase preparation.     

Einfluß der Klärmittel und ihrer Menge auf die polarimetrische Bestimmung der Stärke nach Ewers bei Weizen-, Mais- und Kartoffelstärke

Influence of Clearing Agents and their Amount on the Polarimetric Determination of Starch According to Ewers with Wheat, Maize and Potato Starch According to chemical analysis and statistical evaluation the clearing agent by Carrez will seem the most suitable. Lowest suitability is shown by phosphotungstic acid of 4 percent, as increasing dosis lowers starch content statistically significantly with all analyzed samples. Ammonium and sodium acetate cause a moderate lowering of the optical activity of starch. This lowering is not dependent upon the amount of the clearing agent. Probably, a sedimentation of starch comes into consideration. Normal as well as basic lead acetate (by Horn) cause a decrease of polarization and thus a decrease of the determined starch content.     

Bericht über Arbeitsergebnisse mit Dorr-Oliver-Apparaturen in der Kartoffelstärkeindustrie

Report on the Results Obtained with Dorr-Oliver Equipment in the Potato Starch Industry Information is disclosed regarding throughput capacity, losses and water consumption of combined D-O DSM potato pulp screening systems and Dorr-Clone washing systems. All informations were obtained during the 1971 campaign in France.     

Erfahrungen mit bekannten und neuentwickelten Maschinen in der Kartoffelstärkeindustrie

Experiences with Known and New Developed Machines in the Potato Starch Industry. With the aid of flowsheets a review is given of the new developments in processing and some new introduced machines, i. e. potato reception and washing installations, a new type of rasp, centrisieves as refining sieves for starch milk, decanters, rotary vacuum filters, and a new drum-belt press.     

Die Selbsthydrolyse der Kartoffelstärke. 2. Mitt. Selbsthydrolyse von Kartoffelstärkekörnern in wäßriger Suspension

Self Hydrolysis of Starch. Part 2. Self Hydrolysis of Potato Starch Granules in Aqueous Suspension. Tests with potato starch have shown that self hydrolysis at temperatures below the starting point of irreversible swelling leads to the formation of low molecular, soluble degradation products containing bound phosphoric acid. The rest of starch granules show increased reducing power as well as hydrothermically caused ageing. Approaching the end of self hydrolysis the substrate acts like thin boiling starch. During self hydrolysis phosphoric acid bound like ester is set free. Speed of self hydrolysis increases with increasing phosphorus content, whereas formation of free phosphate is independent of this factor.