Design and implementation of maple packages for processing offsets and conchoids

In this paper we present two packages, implemented in the computer algebra system Maple, for dealing with offsets and conchoids to algebraic curves, respectively. Help pages and procedures are described. Also in an annex, we provide a brief atlas, created with these packages, and where the offset and the conchoid of several algebraic plane curves are obtained, their rationality is analyzed, and parametrizations are computed. Practical performance of the implemented algorithms shows that the packages execute in reasonable time; we include time cost tables of the computation of the offset and conchoid curves of two rational families of curves using the implemented packages.     

The effect of gestation and of protein quality on the nutritive utilization of protein

A study was made of the effect of protein quality on gestation and on digestive and metabolic utilization in Wistar rats. The protein level of the diet was 14%, and the protein sources used were: casein, beans and a mix of beans and wheat, in order to complement the essential amino-acids deficient in both protein sources. Gestation increased food intake in the 3 groups of experiments, in which distinct protein sources were used. Protein quality did not affect food intake in the two physiological situations under study (gestation and non-gestation). In pregnant animals, the greatest weight gains were obtained with the casein diet, while in non-pregnant ones the weight increases were greater with the diet of beans and wheat. The smallest gains recorded were those of pregnant and non-pregnant rats fed a diet of beans. Gestation did not affect protein-absorption. The digestive utilization of protein was superior with the casein diet. The study of nitrogen retention showed: 1. The pregnant animals retained more nitrogen than the non-pregnant animals with all of the diets under study. 2. In pregnant animals, the greatest metabolic utilization took place with the casein diet, with little difference between the bean and bean-wheat mix diets, although in the latter it was slightly superior.     

Natural fermentation of lentils

Lentil (Lens culinaris var. vulgaris) flour was naturally fermented for 4 days at different temperatures (28°C, 35°C and 42°C) and concentrations (79 g/1, 150 g/1 and 221 g/1). Samples were analysed to establish the changes of total protein content and in vitro protein digestibility, trypsin inhibitor activity (TIA) and phenolic compound content during natural fermentation of lentils. The preparation of lentil flour suspensions to be fermented caused a slight increase in total protein and in vitro protein digestibility content, a decrease of TIA and a sharp decrease the tannin/catechin ratio. During the whole fermentation procedure, the minimum initial lentil concentration and temperature used (79 g/1, 28°C) achieved the maximum protein content and the lowest tannin/catechin ratio. The TIA was more affected by temperature than by concentration, and a 62.5% reduction was observed at 42°C and 79 g/1.     

Nutrients and antinutritional factors in faba beans as affected by processing

 The influence on the nutrients content (soluble sugars, starch, dietary fibre and calcium) and antinutritional factors (α-galactosides and phytic acid) of faba beans (Vicia faba, L. major) of soaking in different solutions (distilled water, citric acid, and sodium bicarbonate solutions), cooking the presoaked seeds, dry-heating and germination have been studied. Soaking brought about a decrease in starch, sucrose, fructose, α-galactoside, dietary fibre and calcium content. Glucose was detected in soaked faba beans and soaking did not modify the phytic acid content. Cooking the presoaked faba beans produced a slight decrease in starch, and caused a general drop in α-galactosides, dietary fibre, calcium and phytic acid, with the exception of seeds presoaked in sodium bicarbonate in which cooking did not cause any appreciable changes in comparison with the unprocessed faba beans. Germination caused a sharp reduction in α-galactoside and phytic acid content after 6 days, whilst starch and dietary fibre decreased slightly. Calcium, however, enjoyed a slight increment during germination which was related to the decrease in the content of hemicellulose and phytic acid. Dry-heating caused a noticeable reduction in all the nutrients and antinutritional factors investigated. Of all the treatments studied, germination appears to be the best processing method to obtain nutritive faba bean flour, since it caused a minor decrease in starch content (15% loss), the largest α-galactoside and phytic acid removal (94% and 45%, respectively) and provided an appreciable amount of dietary fibre. Received: 21 December 1997 / Revised version: 19 February 1998     

Meat Products as Functional Foods: A Review

ABSTRACT: Numerous studies have sought to demonstrate the possibility of changing the image of meat and meat products from the traditionally accepted image to one of healthy living thanks to the addition (vegetables, extracts, fibers, and so forth), elimination (fats), and reduction (additives) of different ingredients. This article presents a revision of studies published in recent years on the topic and looks at possible future trends in the sector, analyzing the changes that have occurred in the traditional meat industry as global forces in the agro food industry direct it more and more to the design and production of functional foods.     

Effect of natural fermentation on carbohydrates, riboflavin and trypsin inhibitor activity of lentils

Lentils were subjected to natural fermentation for 4 days at 30°C. The pH value fell to 3.8 during the process. -Galactosides and sucrose were not detected in fermented lentils but a significant increase in the fructose content was observed. In fermented lentils the neutral detergent fibre, cellulose and hemicellulose contents decreased and the lignin content increased. After fermentation the riboflavin content was higher and the trypsin inhibitor activity decreased.

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Einfluß der natürlichen Fermentation von Linsen auf den Kohlenhydratgehalt, Riboflavingehalt und die Trypsininhibitor-Aktivität

Zusammenfassung Es wurde die Linsenfermentation durch natürlich vorkommende Mikroorganismen während 4 Tage durchgeführt. Die Temperatur wurde bei 30°C gehalten. Durch die Vergärung fällt der pH-Wert auf 3,8. -Galaktoside und Saccharose wurden in den Linsen nicht nachgewiesen, jedoch eine signifikante Zunahme des Fructosegehaltes. Es zeigte sich, daß in den Linsen die neutrale Detergent-Faser, der Cellulose- und Hemicellulosegehalt und die Trypsininhibitor-Aktivität abnimmt, aber der Lignin- und Riboflavingehalt zunimmt.

     

Influence of fermentation on the nutritional value of two varieties of<Emphasis Type="Italic"> Vigna sinensis</Emphasis>

Cowpeas ( Vigna sinensis) are a good source of protein and energy. They are widely consumed all over the world, mainly in rural populations, and satisfy a considerable proportion of the protein requirements. However, like other pulses, cowpeas contain several antinutritional factors, which limit their consumption and affect the digestibility and bioavailability of nutrients. Fermentation seems to enhance the nutritive value of legumes. The present work studies the effect of natural fermentation and subsequent cooking process of two varieties of Vigna sinensis on the content of protein, minerals, ash, fat, soluble and insoluble dietary fibre, -galactosides, inositol phosphates, trypsin inhibitor activity (TIA), water-soluble vitamins (thiamin and riboflavin) and protein quality parameters, in vivo digestibility and PER (protein efficiency ratio). The processes applied caused a significant increase of vitamin B_2, and significant reductions in the contents of TIA (40%) and phytates (100%), main antinutritional factors present in cowpeas. Likewise, the soluble fibre and -galactosides compounds that produce flatulence diminished (67 and 100%, respectively). Protein digestibility for Orituco variety was adequate among legumes (82.8–88.4%), although only Vigna sinensis var. Orituco showed an acceptable PER value (1.63).     

ULSI/GLSI低Na CMP浆料的纯化效率

采用离子交换法去除ULSI/GLSI CMP浆料SiO2水溶胶中的Na+.介绍了微电子专用CMP SiO2水溶胶纯化的研究现状.实验分析了SiO2水溶胶中Na+与阳离子树脂的交换机理,硅溶胶中Na+去除分为硅溶胶溶液中Na+的去除和被硅溶胶胶团吸附Na+的去除.在交换动态平衡时,动态交换1h较静态交换24 h生产效率提...     

Lignocellulosic-derived catalysts for the selective oxidation of propane

The formation of dispersed VPO phases on a lignocellulosic-based activated carbon results in a catalyst that is selective for the partial oxidation of propane, and stable under oxidizing conditions. The use of a stable activated carbon as a catalytic support for active VOx species during the partial oxidation of propane is described for the first time.