Verwendung von Kartoffelpülpe und Kartoffelfruchtwasser als Nährmedium zur Anzucht von Laccase produzierenden Pilzen

Utilization of Potato Pulp and Potato Liquor for the Production of Laccase by Selected Basidiomycetes. Potato processing wastes were used for the production of enzyme laccase (polyphenol oxidase) by selected strains of Trametes villosa, T. versicolor and Polyporus brumalis. They were capable of utilizing these wastes as the sole carbon and nitrogen source. Maximum activities of laccase was obtained with the optimized mixtures of 5% potato pulp and 4% of potato liquor. Several basidiomycetes strains, when grown on potato wastes, can synthetize alpha-amylase (e.g. Trametes villosa). The amino acids and trace elements in pulp and liquor were analysed. Asparagine and aspartic acid are the main constitutents of amino acid fraction of the potato liquor under the test. Cultivation of Trametes villosa on potatostarch processing wastes can be used for the inexpensive production of valuable fungal enzymes.     

Herstellung von Gärungsethanol aus Nebenprodukten der Stärkeindustrie,insbesondere aus Kartoffelpülpe

Production of Ethanol from Starch Industry By-products, Especially from Potato-Pulp The paper presents a fermentation plant, in which wastes and by-products from potato-and wheat-starch factories, starch derivatization, starch saccharification and production of potato flakes with different quality and varying amounts can be fermented to ethanol. Special attention is put on potato pulp which represents the greatest part of by-products and whose marketing in wet form at best covers, costs or even is leading to significant expenses in the case of drying. Due to the composition it is difficult too to ferment potato pulp to ethanol in conventional plants especially caused by its contents of gelling materials such as pectin and hemicelluloses. As a result of respective work referring to this a hydrolysis process is described which is especially geared towards obtaining hydrolysates possibly high in dry matter contents with respect to the subsequent fermentation.     

Beitrag zur mechanischen Entwässerung von Kartoffelpülpe

Contribution to the Mechanical Dewatering of Potato Pulp. In the Federal Republic of Germany 600 000 t potatoes yearly are processed by the domestic potato starch industries. This production results in large quantities of potato pulp as by-product which can be utilized economically to a limited extent only. The main field of application is the utilization as animal feed either in wet condition or after drying process. For this purpose, the potato pulp is dewatered mechanically and then dried preferably in flash-driers. As result of the mechanical dewatering of potato pulp even in most modern pulp presses and with extremely high pressures max. 25% d. s. are to be obtained only. In order to increase the mechanical dewatering effect an thereby to decrease the energy expenses of the following thermal dehydration attemps have been made to disintegrate the potato pulp to the most possible extent by an alternative chemical or enzymatic pretreatment. When using kieselguhr the dewatering effect could be increased by around 5% from 26% d. s. to 31% d. s., whereas the application of calciumchloride effected an increase of almost 11% from 29% d. s. to 40% d. s. Under the test conditions also the application of pectolytic enzymes in liquid form increased the yield by 10% d. s.     

Untersuchungen an Kartoffelpulpe als Ballaststoffquelle. Zum Einfluß Von pektolytischen und cellulolytischen Enzymen

Investigations on potato pulp as a dietary fiber source. The influence of pectolytic and cellulolytic enzymes . The influence of treatment with pectolytic and cellulolytic enzyme preparations was investigated with reference to the separation of water and the composition of potato pulp. In contrast to pectinesterase, pectate lyase or cellulase it was found an intensive action on the pulp after incubation with Pectinex Ultra SP-L or pectinase/cellulase combinations. The content of pectin, starch and protein as well as the water binding capacity are varied in dependence of the used enzyme preparations. The occurring changes in the supermolecular structure of the potato pulp tissue are investigated by scanning electron microscopy. The grown biological structure is partly or extensive destroyed especially after combined action of pectinases and cellulases. The content of starch in the potato pulp preparations remains relatively high even after intensive treatment with cell wall degrading enzymes.     

Die Verteilung von Stärke und Amyloseanteilen in der Kartoffelknolle

Distribution of Starch and Amylose Components in the Potato Tuber. Distribution of dry matter and starch in potato tubers has been studied. Moreover, distribution of amylose components of the starch and qualitative properties of the isolated starch as well as the interrelation between the received data have been examined. From the results it is seen that with most varieties a tendency towards an increase of the dry matter content at the navel end is perceptible. This tendency is more distinct with big tubers. On an average, the starch content was higher at the navel end than at the crown end of the tuber with almost all samples. Starch from big tubers shows a higher viscosity than that obtained from small tubers. Viscosity of the starch from the navel end of small tubers is lower than that from the crown end; with big tubers this is the other way round. Amylose content of starch from small tubers is lower than that from big tubers. Starch, which had been isolated from the crown end of small tubers contained mainly a lower amylose content than the starch isolated from the navel end. Again the situation was the other way round with big tubers. Quality of starch is furthermore also determined by the size of the starch granules. With big tubers a higher amount of bigger granules is to be found. This must be contributed to the fact that in big tubers a higher stage of maturity is reached. Another factor that has been very rarely examined so far is the steeping temperature of starch granules. Apparently the vegetation year has its influence on this factor, too. Differences between the two parts of the tuber were insignificant with small tubers. With big tubers the average steeping temperature of granules was higher in the navel end than in the crown end. The whole complex has been examined from the point of view that the origin of the starch does not have a great significance, although here an interrelation might have been expected. The following relations have been stated by means of the correlation coefficient: amylose content, viscosity, granules (21–40 μm), granules (41–70 μm), average granule size. From the results it is clear that the correlation coefficient between starch content and the amylose content is negative. The correlation between granules of the second (21–40 μm) and the third (41–70 μm) category also proved to be negative. From the basis of the correlation coefficients a regression equation for the statistically secured results may be calculated.     

Die Verwendung synthetischer Amylosen als Bezugssubstanzen bei der gelchromato-graphischen Molekulargewichtsbestimmung von Stärken

Application of Synthetic Amyloses as Standards in Gelchromatographic Molecular Weight Determination of Starches. Amyloses of almost uniform molecular size were synthesized from maltoheptaose and glucose-1-phosphate by the action of potatoe phosphorylase. The products of this synthesis were characterized by β-amylolysis, selektive precipitation fractionation and measurements of light scattering, osmotic pressure and intrinsic viscosity. The tests showed complete degradation of the amyloses by β-amylase and P_w/P_n-ratios between 1,00 and 1,15, corresponding very closely to a Poisson distribution. Because of their physicochemical properties the amyloses are very convenient standards for molecular weight determination of starch by gel chromatography. The results were compared with those obtained by calibration with dextran fractions.     

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.     

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.     

Die Einwirkung der Naturweine auf die Zusammensetzung des Urins und die Alkalireserve des Blutes

Ohne Zusammenfassung     

DSC-Untersuchungen an Stärken. Teil II. Untersuchungen an Stärke-Lipid-Komplexen

DSC Investigations of Starches. Part II. Investigations on Starch-Lipid-Complexes. Starch-lipid-complexes are present in native starches, especially in cereal starches. Such complexes as well as those formed with added emulsifiers play an important role during application of starches and flours, e.g. within baking. Starch-lipid-complexes or amylose-lipid-complexes can be well characterized by Differential-Scanning-Calorimetry (DSC), while amylopectin-lipid-complexes could not yet be detected. The formation and the thermal stability of complexes with fatty acids depend on the chain length and the degree of unsaturation. The thermal stability increases with increasing chain length for saturated fatty acids and decreases with increasing degree of unsaturation for the unsaturated acids. Within a temperature range between 70–100°C a characteristical reorganization can occur which is described in detail.     

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.     

Die thermische Zersetzung von D-Glucose Teil 3. Die Ausbeuten an flüchtigen Produkten und die quantitative Zusammensetzung der Pyrolyseprodukte

Thermal Decomposition of D-Glucose. Part 3. Yields of Volatile Products and Quantitative Composition of the Pyrolysis Products . Yields and quantitative composition of product obtained from slow pyrolysis of D-glucose under nitrogen and hydrogen in the temperature range from 300 to 1000°C were determined. It was found that glucose may be highly extensively transformed into volatile products at sufficiently high pyrolysis temperatures, especially if the pyrolysis is carried out under hydrogen. At higher pyrolysis temperatures a higher content of aromatic carbohydrates and alcohols is gained, extraction of these technologically interesting products, however, is extremely difficult due to the multiplicity of pyrolysis products.