Veränderungen des Gehaltes an Pektinstoffen in gekochten Kartoffeln

Variations of Content of Pectinic Substances in Boiled Potatoes. From 1976 to 1978 greenhouse and open field experiments were carried out under different fertilizing conditions. The content of pectin substances as well as their degree of esterification of boiled and fresh tubers were determined. The content of pectins in boiled tubers was depending on fertilizing doses, phase of vegetation, potato sort and storing period. It was substantially decreased by boiling. The extent of the reduction is connected with potato sort, vegetation period, storing time and fertilization. The degree of esterification of pectin substances is varied by fertilizing with calcium and magnesium. Result from greenhouse experiments are differing from those of open field experiments. They reveal the importance of different pectin contents with regard to the texture of potatoes.     

Inactivation of Escherichia coli in milk by high-hydrostatic-pressure treatment in combination with antimicrobial peptides

We studied the inactivation in milk of four Escherichia coli strains (MG1655 and three pressure-resistant mutants isolated from MG1655) by high hydrostatic pressure, alone or in combination with the natural antimicrobial peptides lysozyme and nisin and at different temperatures (10 to 50 degrees C). Compared with that of phosphate buffer, the complex physicochemical environment of milk exerted a strong protective effect on E. coli MG1655 against high-hydrostatic-pressure inactivation, reducing inactivation from 7 logs at 400 MPa to only 3 logs at 700 MPa in 15 min at 20 degrees C. An increase in lethality was achieved by addition of high concentrations of lysozyme (400 microg/ml) and nisin (400 IU/ml) to the milk before pressure treatment. The additional reduction amounted maximally to 3 logs in skim milk at 550 MPa but was strain dependent and significantly reduced in 1.55% fat and whole milk. An increase of the process temperature to 50 degrees C also enhanced inactivation, particularly for the parental strain, but even in the presence of lysozyme and nisin, a 15-min treatment at 550 MPa and 50 degrees C in skim milk allowed decimal reductions of only 4.5 to 6.9 for the pressure-resistant mutants. A substantial improvement of inactivation efficiency at ambient temperature was achieved by application of consecutive, short pressure treatments interrupted by brief decompressions. Interestingly, this pulsed-pressure treatment enhanced the sensitivity of the cells not only to high pressure but also to the action of lysozyme and nisin.     

Characterization of palladium supported on sulfated zirconia catalysts by DRIFTS, XAS and n-butane isomerization reaction in the presence of hydrogen

Palladium supported on sulfated zirconia (PdSZ) has been characterized by the n-butane isomerization reaction in the presence of hydrogen, X-ray absorption spectroscopy (XAS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) of adsorbed carbon monoxide. Catalyst calcination at 873 K followed by hydrogen reduction at 513 K results in the formation of 30–40 Å Pd metal clusters, but the surface can only weakly adsorb CO, though stronger than Pd-free, sulfated zirconia catalysts. In the presence of hydrogen, PdSZ has a lower n-butane isomerization activity than SZ, and the Pd function cannot stabilize the reaction at low H₂/n-butane ratios.     

Effect of heat treatment and milling on the seed, flour, rheology and baking quality of some amaranth ecotypes

Forty-five harvests corresponding to the two predominating domestic species of amaranth in Mexico were studied. The proximate analysis revealed some statistically significant differences throughout three years of observation. The Ca, P and Fe content did not vary greatly in 15 samples. No chemical differences were either manifested in the Mercado and Aztec types of A. hypochondriacus, nor in the Mexican type of A. cruentus. The latter exhibits a higher grain yield and a shorter life cycle; however, its baking quality is apparently inferior to that of the Mercado type of A. hypochondriacus. The heat treatment of the seeds (toasting, popping and cooking) affected protein and lysine contents as does in cereals and leguminous seeds although toasting in particular improves its sensory characteristics without altering digestibility and PER. Popping only improves PER. Heating at 90 or 170 degrees C for three to five minutes, at the usual seed's moisture rate of 6 to 15%, does not affect protein content and does so only slightly in the case of the fatty acids content. Amylographic and farinographic values of the starchy fractions indicate similarities to C. quinoa and differences with respect to wheat. In the case of "amaranth milk", viscosity and gelatinization temperature produced satisfactory values. The extension of amaranth cultivation in the country is hereby suggested in view of the seed's nutritional quality, and considering the behavior of whole amaranth flour and its fractions.     

Retention of Eucalyptol,a Natural Volatile Insecticide,in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.     

Development of bakery products for greater adult consumption based on wheat and rice flour

The present investigation was developed as a contribution to Guatemalan's elderly food and nutrition. Its main objective was to evaluate the chemical, nutritional and sensory quality of bread prepared from the partial substitution of wheat flour with rice flour. Wheat flour substitutions with rice flour in the order of 15, 20, 30, 40, 50 and 60% were evaluated. Differences with the control (100% wheat bread) were found during the process of preparation, as well as texture, volume, height, weight and specific volume. Important effects in dough handling were noted specifically in the 40, 50 and 60% rice bread. Thus, a sandy texture was found in breads of higher rice levels. The bread protein quality increased with the level of substitution; however the protein quality difference between the wheat bread and the bread with 60% rice flour did not achieve statistical significance. Based on a statistical analysis of the physical properties the bread with 30 and 40% rice flour was selected, and through a preference test between these last two, the 30% rice flour bread was selected as the sample best suited to the present study's purposes. This bread was not different to wheat bread in many nutritional parameters, although in others it showed to be superior. Each serving size of bread has a weight of 80 grams (2 slices) that contributes adequate quantity of calories, protein and sodium, although a little less dietary fiber than 100% wheat bread.     

Discriminating power of the hydrocarbon content from virgin olive oil of extremadura cultivars

Samples of virgin olive oils (105) from seven Extremaduran olive varieties (Cacereña, Carrasqueña, Cornezuelo, Corniche, Morisca, Picual, and Verdial de Badajoz) in three stage of maturity (green, semi-ripe, and ripe) were collected and the alkane, alkene, and sesquiterpene contents determined. There were significant differences at the 0.01 probability level in most of the hydrocarbons, both by variety and by state of maturity. Discriminant analysis applied to 70 samples explained 72.3% of the variance between the different groups of varieties and allowed 90% of the samples to be classified according to their variety. The acceptability of the model was verified against the remaining 35 samples, giving a mean level of correct classification of 94%.     

New lake district in Europe: origin and hydrochemical characteristics

This article presents a new lake district in Southern Poland created as a result of human activity in the Upper Silesian region. The area has been named the Upper Silesian Anthropogenic Lake District. The lake density of the Lake District as delineated by the authors (with an area of 6766 km²) is 2.74%. It includes 4773 water bodies of various origins – reservoirs retained by dams, flooded mineral workings, water bodies formed in subsidence basins and hollows, levee ponds, residual water bodies following river regulation and other water bodies. These are located in urban‐industrial, rural‐agricultural or quasi‐natural areas. The hydrochemical diversity of water bodies is conditioned by their origin, location in the catchment and function. Studies have shown the widespread occurrence of eutrophication processes in limnic waters within the Lake District. The diverse origin and hydrochemical properties of water bodies within the Upper Silesian Anthropogenic Lake District make it special among other anthropogenic lake districts.     

Model selection, identification and validation in anaerobic digestion: a review

Anaerobic digestion enables waste (water) treatment and energy production in the form of biogas. The successful implementation of this process has lead to an increasing interest worldwide. However, anaerobic digestion is a complex biological process, where hundreds of microbial populations are involved, and whose start-up and operation are delicate issues. In order to better understand the process dynamics and to optimize the operating conditions, the availability of dynamic models is of paramount importance. Such models have to be inferred from prior knowledge and experimental data collected from real plants. Modeling and parameter identification are vast subjects, offering a realm of approaches and methods, which can be difficult to fully understand by scientists and engineers dedicated to the plant operation and improvements. This review article discusses existing modeling frameworks and methodologies for parameter estimation and model validation in the field of anaerobic digestion processes. The point of view is pragmatic, intentionally focusing on simple but efficient methods.     

Integrated material flow and radioactivity distribution methodology within the calculation tool for evaluation of parameters for decommissioning of nuclear installations

Decommissioning of nuclear facilities becomes an important issue in all areas of nuclear technology, mainly in their energetic applications. Decommissioning process has to be planned in the safe, ecological and economic manner. It determines the requirements on appropriate evaluation of needed technologies, media, amount of solid materials released into the environment, radioactivity of effluents, amount of radioactive waste for disposal, number and exposure of personnel and finally the financial demands. A detailed evaluation of these parameters may be done by analytical calculation approach. This approach models a real process of decommissioning with its individual basic activities. The methodology of integrated material flow and radioactivity distribution within this calculation evaluation tool is applied and implemented to describe the real decommissioning activities and their mutual relations to obtain more accurate outputs.