EVALUATION OF THE NUTRITIONAL QUALITY OF NONTOXIC KERNEL FLOUR FROM JATROPHA CURCAS L. IN RATS

ABSTRACT

The origin of Jatropha curcas L. is in Central America, probably Mexico, although it is also distributed in South America, Africa and Asia. In Mexico, it grows as nontoxic and toxic J. curcas genotypes. In this work, the protein quality including protein efficiency ratio (PER), net protein ratio (NPR) and true digestibility (TD) of nontoxic genotype defatted flour was assessed using Wistar rats. The probed diets contained flour (3), flour‐lysine, 1% (4), flour‐phytase, 500 FTU (5) and two control diets: nitrogen‐free (1) and casein (2). The rats were fed for 28 days. The PER (1.37, 1.77 and 1.61) and NPR (1.80, 2.29 and 2.12) obtained values for diets (3.4 and 5) were lower than those obtained for casein (2.07 and 2.46), respectively. No statistical differences were found in TD.

PRACTICAL APPLICATIONS

Jatropha curcas defatted flour may be used in the food industry for the development of diets for human and animal consumption. Besides achieving fortification of foods that are made from wheat, which has a low protein content, with the addition of Jatropha meal, these foods will improve the protein quality of many food products.     

MODIFICATION OF THE LOW-MOLECULAR WEIGHT BASIC ALBUMIN FRACTION FROM RAPESEED (BRASSICA NAPUS L.) BY ACETYLATION PART 1. CHEMICAL AND PHYSICOCHEMICAL ASPECTS1

The chemical and physicochemical changes of the low-molecular weight basic albumin fraction from rapeseed, as a function of degree of acetylation, were studied using amino and ester groups analyses, PAGE electrophoresis, isoelectric focusing, viscometry, circular dichroism and fluorescence spectroscopy. The surface hydrophobicity was evaluated by means of the ANS fluorescence probe technique. The protein was readily acetylated at the amino groups by addition of acetic anhydride. Acetylation of amino acid hydroxyl groups was significantly slower and proceeded in the presence of an excess of the reagent after the amino groups had already been blocked. Acetylation resulted in protein species with isoelectric points at pH 7.6, 6.6, 5.95 and 5.4. The intrinsic viscosity of the native protein fraction dropped from 0.159 dlg^?1 to 0.038 dlg^?1 at a moderate degree of modification. The secondary structure of the protein, characterized by a content of 40–45% helix conformation, was not significantly influenced by acetylation. Modification did not result in wavelength shifts of the peaks in the near ultraviolet CD and fluorescence spectra. However, the negative ellipticities in the 250–270 nm region of the CD spectrum increased markedly with increasing degree of acetylation. The surface hydrophobicity increased linearly with the amount of acetyl groups introduced into the protein.     

Ionic Conduction in Alkali and Thallium Silicate Glasses

Electrical conductivities of binary alkali and thallous silicate glasses have been measured as a function of composition, temperature, and frequency. The best approximation to the activation energy for dc conduction can probably be obtained by extrapolating its frequency dependence to zero frequency, although values obtained at frequencies below 2500 hz do not differ greatly from the dc values. The plot of activation energy for conduction against modifier content consists of two straight lines of different slope. For all the alkali silicate glasses the break in slope occurs near 25 mole % alkali oxide and at an activation energy near 14.7 kcal/mole. The slope of the line below 25 mole % alkali oxide is proportional to the alkali ion radius. The behavior of thallous silicate glass is similar but not identical to that of the alkali silicates. It is concluded that (1) the reported conduction behavior does not result primarily from phase separation, (2) the principal contribution to the activation energy is probably the work required for a mobile ion to pass through the glass network rather than to leave its initial position, and (3) a structural change independent of the nature of the modifier cation occurs near a modifier content of 25 mole %.     

3-mirror quasi-optical power combining of millimetre-wave sources

In order to achieve high power readily for applications such as plasma heating in fusion, it is required that the outputs of several gyrotron tubes be combined. A new kind of 3-mirror quasi-optical power combiner has been presented and studied in this paper. Both theoretical and experimental study point out that the proposed power combiner has attractive features. It seems that this 3-mirror quasi-optical power combiner may not be used only for high power millimetre gyrotron power combining, but also for millimetre and submillimetre solid state power combining     

TRIACYLGLYCEROL ANALYSIS OF VEGETABLE OILS BY MATRIX-ASSISTED LASER DESORPTION AND IONIZATION TIME-OF-FLIGHT (MALDI-TOF) MASS SPECTROMETRY AND 31P NMR SPECTROSCOPY

Triacylglycerols play an important role in nutrition and cosmetics, but are also of significance in a number of diseases. Because of their commercial importance, there are different established analytical techniques of composition analysis. Most of these methods are, however, relatively time-consuming. In this study we used a matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) for characterization of different vegetable oils. Products with acidic -OH groups (derived from triacylglycerols) were additionally detected by ³¹P NMR after derivatization with chlorophosphane. The combination of these two methods is very advantageous. Whereas MALDI-TOF provides very fast and reliable information on the fatty acid composition of lipid samples by detection of the corresponding triacylglycerol molecular ions, the detection of monoacylglycerols and especially free fatty acids is difficult. In contrast, such compounds can be easily detected by ³¹P NMR spectroscopy, but with a lower sensitivity. Due to the rapid performance, high sensitivity and the quantification of spectra, the combination of both methods provides a promising new tool in lipid analysis.     

Efficient order quantities: the dynamic case

When fixed reordering costs and/or carrying rates are not known, efficient instead of optimal order quantities may be calculated by allocating the available reordering capacity to storage items such that the implied inventory investment is minimized, or vice versa. Static versions of this problem have been discussed in detail elsewhere. The present paper develops an algorithm suitable for calculation of efficient order quantities under conditions of dynamic multi-item demands.     

TOWARDS A NEW ATLAS OF SOLAR RADIATION IN EUROPE

A new solar radiation atlas for Europe up to the Ural and including neighbouring mediterranean territories will be produced by a European group of experts. The atlas will be oriented towards the needs of the users like solar architects and engineers, respecting the state of the art of their working field and their need of precise input data.

rom best available measured solar data complemented with other meteorological data necessary for solar engineering, maps for the European continent will be produced. Satellite images will help to improve precision. TRY or DRY will be included. The “hard copy” atlas will be complemented by a PC-package including a data base whith the mapping in digital form with high resolution, algorithms to calculate derived parameters and input files for engineering problems. The PC-package will be complemented by a users' guidebook. Information from past and ongoing CEC solar projects will be integrated.