Nutritional quality of some landraces of pearl millet Pennisetum Glaucum grown in hyperardi ecosystem

Pearl millet Pennisetum glaucum is the most widely grown type of millet considered as secondary cereal. The center of biodiversity is in the Sahel zone of West Africa. It's known to be well adapted to drought, low soil fertility, and high temperature. Pearl millet is an important food across the Sahel. It is a main staple in a large region of Nigeria, Niger, Mali and Burkina Faso. India is the largest producer of pearl millet. The Sahara of Algeria which is a hyper arid region bordering the Sahel countries include many landraces. The aims of this study were to determinate the nutritional value of grains from some landraces of pearl millet. The protein, starch, fat, fiber, soluble sugar and minerals contents were obtained. An important interest was given to starch, as energetic source, so the ratio of amylose and amylopectin and some of its properties as rheological and thermal properties were determinate and showed interesting values comparatively to those given by previously studies done on pearl millet grown in different ecosystems. Pearl millet grains are gluten free and rich in starch, protein and minerals; it exhibits interesting applications in food and health, especially for celiac, anemic and cardiac patients and it is recommended for children growth. The grain components and their properties can present a competitive potential to satisfy specific, technological and nutritional needs for target market. Conservation and use of genetic diversity of millet in farming systems are at the heart of important issues, including food self-sufficiency

Kinetic of Sorghum starches bioconversion using various a-amylases

Industrial enzymology is an important branch of biotechnology. Enzymes offer alternative ways of making products previously made using conventional chemical. Originally, acid conversion was used to produce glucose syrups but today alpha-amylase are used to hydrolyze starches. Corn starches are the most useful industrially despite that Sorghum (Sorghum bicolor (L.) Moench) starches exhibit interesting properties. These properties show variability according to genotype and influence the digestibly of starch in the presence of amylases. The aim of this research is to determine the susceptibility of isolated starches from different cultivars of sorghum cultivated in hyper arid ecosystems of the Sahara of Algeria to the bioconversion using pure α-amylases and so to study the influence of the genotype of sorghum on the liquefaction and saccharification which respectively produce dextrin and reducing sugars. Many authors have reported that properties of starch as amylose content, solubility affect the starch behaviour during the enzymatic hydrolysis as well as mechanism of action of amylases. Starches sorghum were isolated and purified in the laboratory from white and pigmented seeds of cultivars from Algeria (In Salah), and United States of America. Some of their characteristics were determined. Amylases used were from fungal and bacterial sources (α-amylase from Aspergillus oryzae α-amylase from Bacillus subtilis), which possess an important hydrolysis activity. The kinetic studies of enzymatic catalysis had allowed to identify of optimum operating conditions and to calculate enzymatic activities. We also highlight the influence of genotype on starch bioconversion. Indeed, the composition and concentrations of maltoolisaccharides obtained after amylase hydrolysis were determined using HPAEC-PAD and results of profiles show differences according the sources of starch and amylase. This study is of great importance to consider industrial bioconversion of starches to produce oligosaccharides syrups

Isolation and chemical characterization of pearl millet starches from Algeria

Starch is the most important carbohydrate in the human diet. Depending on botanical origin and genetic background, starch has different chemical structures, and so different functional properties. Native starch constitutes a key ingredient in numerous food and chemical applications as well as its modified products. The word production reaches 60 million tons with an average growth rate of 2,4 %. Industrially, Starch is isolated from corn, wheat and potato. Pearl millet grain cultivated in the Algerian Sahara present 59, 8 -68, 8 % of starch so we focused on isolation and characterization of this starch. For that, four (4) cultivar samples of pearl millet were collected from In Saleh, Tamanrasset (Algeria) and Agadez (Niger) regions and starch was isolated using modified alkaline method. The isolated starches were pure (93 – 97%). Some physicochemical and functional properties as granules size, thermal and rheological properties were determined. Pearl millet starches exhibit unique properties. Indeed, it has a high gelatinization temperature (75°C) and very high viscosity (4872 cP) compared to starches of pearl millet growing in other ecosystems and other botanical sources (corn, wheat ...). These properties makes them suitable for applications in cosmetic and pharmaceutical industries as powders, in food as Thickener and texturizing, and in chemistry industries as thin, resistant and biodegradable films for embedding or encapsulation

Effect of a-amylase source on enzymatic activity in Sorghum Starch Hydrolysis

Sorghum (Sorghum bicolor (L.) Moench) exhibit unique starches properties. These properties influence the digestibility of starch in the presence of a-amylases and can be a good raw material for glucose production. The aim of this research is to determine the susceptibility of amylase from different sources: a-amylases from human salivary, a-amylases from fungy (Aspergillus oryzae) and a-amylases from bacteria (Bacillus subtilis) and show how the source of amylase affects the atcivities in starch hydrolysis. Starch sorghum was isolated and purified in the laboratory from white and pigmented seeds of cultivars from Algeria In Salah). The enzymatic hydrolysis reactions were done in batch bioreactors and the reducing sugars obtained were determined quantitatively and qualitatively using HPAEC-PAD. The kinetic studies of enzymatic catalysis had allowed to identify of optimum operating conditions and to calculate enzymatic activities. The results showed a significant influence of amylase source on the kind of maltooligosaccharides. The fungal a-amylases is more efficient than bacterial a-amylases

The prototypical inhibitor of cholesterol esterification, Sah 58-035 is an agonist of estrogen receptors.

We have recently shown that estrogen receptor (ER) ligands share a diphenyl ethane (DPE) pharmacophore with Sah 58-035, a prototypical inhibitor of the Acyl-Cholesterol-Acyl-Transferase (ACAT), which enabled us to establish that ER ligands were potent inhibitors of ACAT and blocked the formation of foam cells. In the present study, we have tested whether this structural similarity means that Sah 58-035 is an ER modulator. We report that Sah 58-035 bound to ERalpha and ERbeta with an IC50 of 2.9 microM and 3.1 microM respectively. Docking studies using molecular modeling of Sah 58-035 with the X-ray structure of the ER showed that Sah 58-035 fits well into the ligand binding site known for 4-hydroxy-tamoxifen. Despite having high three dimensional structural similarities with the pure antiestrogen ICI 164,384, we showed that Sah 58-035 is an agonist of ER for transcription and cellular proliferation. These data showed that Sah 58-035 was an estrogen receptor agonist, and that the size and the chemical nature of the side chain were critical for agonist versus antagonist activity on ER. This new molecular mechanism of action for Sah 58-035 has to be taken into account in understanding better its pharmacological activities. Moreover these data give new structural insights into the understanding of agonist versus antagonist activities of ER ligands and also for the conception of new drugs with a dual ACAT inhibition and ER modulation potential and their evaluation in different pathologies where both targets are involved, such as atherosclerosis, Alzheimer's disease and cancer

Physicochemical and functional properties of starches from sorghum cultivated in the Sahara of Algeria

Pure starches were isolated from white and red sorghum cultivated in Tidikelt, a hyper and region situated in south Algeria. Amylose content, X-ray pattern and theological properties of starches were examined. The amylose content in white sorghum starch (27.1%) was slightly higher than that in red sorghum (24.8%). The swelling power and the solubility behavior of both starches were nearly similar below 65 degrees C. At higher temperatures, starch isolated from the white sorghum cultivar showed higher swelling power and lower solubility index than pigmented sorghum starch. The pasting properties of starches determined by RVA, Rapid Visco Analyser showed different viscosity peaks. Red sorghum starch had a higher value (4731 cP) than white sorghum starch (4093 cP). For both sorghum, X-ray diffractograms exhibit an A-type diffraction pattern, typical of cereal starches and the relative degrees of crystallinity were estimated at 22.72% and 28.91%, respectively, for local white and red sorghum starch. DSC analysis revealed that sorghum starches present higher temperatures at the peak (70.60 and 72.28 degrees C for white and red sorghum starches, respectively) and lower gelatinization enthalpies (9.087 and 8.270 J/g for white and red sorghum starches, respectively) than other cereal starches. The results showed that physicochemical and functional properties of sorghum cultivar starches were influenced by the genotype and the environment. (C) 2009 Elsevier Ltd. All rights reserved