Main Amino Acids Research Articles

Free amino acids profile of Polish and Slovak honeys based on LC-MS/MS method without the prior derivatisation.

LC-MS/MS method was applied for determination of free amino acids in honey without derivatisation steps. Twenty free amino acids including aspartic acid, asparagine, glutamic acid, glutamine, alanine, arginine, glycine, leucine, histidine, hydroxyproline, isoleucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, valine and ornithine were analyzed in thirty honey samples from Poland and Slovakia. The analysis covered: acacia, lime, rape, multifloral and forest types of honey. Applied method was characterized to had good sensitivity with limit of detection ranged from 3.0ng/cm3 for valine to 13.0ng/cm3 for hydroxyproline. Average content of proline (main amino acid component in honey) ranged from 151.46μg/g (rape honey from Slovakia) to 389.66μg/g for forest honey (honeydew honey) from Poland. In analyzed honeys large quantities of glutamine, glutamic acid, lysine, phenylalanine, asparagine, alanine, and valine were also found.

Quality of Cultured Wader Pari During Storage at Different Temperature

Gelatin is one of the products which become a necessity for various industries, i.e. food and non-food industries. The application of gelatin has been increasing year by year in Indonesia. However, there is no<br />gelatin industry in Indonesia so far. Thus, it is necessary to find an alternative source of gelatin, especially from fishery by products.Thus, the purpose of this research was to extract fish skin gelatin of yellowfin tuna with temperature treatments (55, 65 and 75oC). In addition, the properties of resulted gelatin were determined including yield, pH, gel strength, viscosity, functional groups, molecular weight profiles, and amino acid composition. The extraction at 75oC was chosen as the best result. The yield was 17%; pH 5.3; gel strength 1789.55 gf, viscosity 104.2 Cp, respectively. There was functional group amide A, I, II, dan III. SDS-PAGE showed β, α1 dan α2 bands for tuna skin gelatin. In addition, the main amino acids were glycine and proline.

Reduced Stress and Improved Sleep Quality Caused by Green Tea Are Associated with a Reduced Caffeine Content.

Caffeine, one of the main components in green tea, can interfere with sleep and block the effect of theanine. Since theanine, the main amino acid in tea leaves, has significant anti-stress effects in animals and humans, we examined the effects of green tea with lowered caffeine content, i.e., low-caffeine green tea (LCGT), on stress and quality of sleep of middle–aged individuals (n = 20, mean age 51.3 ± 6.7 years) in a double-blind crossover design. Standard green tea (SGT) was used as the control. These teas (≥300 mL/day), which were eluted with room temperature water, were consumed over a period of seven days after a single washout term. The level of salivary α-amylase activity (sAA), a stress marker, was significantly lower in participants that consumed LCGT (64.7 U/mL) than in those that consumed SGT (73.9 U/mL). Sleep quality was higher in participants that consumed a larger quantity of LCGT. In addition, a self-diagnostic check for accumulated fatigue was significantly lower in those participants that consumed LCGT than SGT. These results indicate that LCGT intake can reduce stress in middle-aged individuals and improve their quality of sleep. The reduction in caffeine is suggested to be a valid reason for enhancing the anti-stress effect of green tea.

Identification of botanical origin of Chinese unifloral honeys by free amino acid profiles and chemometric methods

The amino acid contents of five floral sources Chinese honeys (jujube, rape, chaste, acacia, and lungan) were measured using reversed phase high-performance liquid chromatography (RP-HPLC). The results showed that proline was the main amino acid in most of the analyzed samples. Phenylalanine presents at the highest content in chaste honey samples, and the total amino acid contents of chaste honeys were also significantly higher than those of other honey samples. Based on the amino acid contents, honey samples were classified using chemometric methods (cluster analysis (CA), principal component analysis (PCA), and discriminant analysis (DA)). According to the CA results, chaste honeys could be separated from other honeys, while the remaining samples were correctly grouped together when the chaste honey data were excluded. By using DA, the overall correct classification rate reached 100%. The results revealed that amino acid contents could potentially be used as indicators to identify the botanical origin of unifloral honeys.

Novel synthesis of isoindoline/isoindoline-1,3-dione derivatives under solventless conditions and evaluation with the human D2 receptor

Isoindolines are the focus of much research because of being an important family of compounds present in a wide array of bioactive molecules. Although many different pathways of synthesis have been described, they do not follow green chemistry principles. The aim of this contribution was to develop a green synthesis technique for isoindolines/dioxoisoindolines. These compounds derived from analogs of important biogenic amines were tested in silico (on the human dopamine receptor D2) to predict their affinities and some pharmacokinetic parameters. One of them, YaI-01, was evaluated in vivo in a Parkinsonism mouse model. Seven molecules, including three isoindolines and four dioxoisoindolines, were synthesized using simple heating and relatively quick solventless reactions. They were then purified with a methodology as green as possible. Since no published crystal structure exists for dopamine receptor D2, it was necessary to generate and validate a homology model for molecular docking studies of the seven molecules synthesized presently. Docking was performed to assess affinity in terms of binding energy (∆G). Apart from pharmacokinetic parameters, Lipinski’s rule of five and some properties of toxicity from QSAR models were evaluated. Whereas no risk was found for the isoindolines, there was evidence of three kinds of toxicity for the isoindoline-1,3-dione compounds. Overall, the in silico analysis suggests that the three isoindolines herein tested have the best properties as ligands of the dopamine receptor D2, interacting with the main amino acid residues at its allosteric binding site. YaI-01 (254 µmol/kg) reverted Parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

Chemical composition of different muscle zones in pirarucu (Arapaima gigas)

Abstract Identifying potential patterns in pirarucu ( Arapaima gigas ) composition, as a function of the different fish muscle zones (dorse, venter, ventrecha and tail), was the main objective of this research. For such, the different pirarucu muscle zones were evaluated, in order to obtain proximate composition and minerals content. It was also determined amino acids and fatty acids contents in fish muscle. The dorsal, ventral and tail muscle zones presented similar moisture (76.5-78.2%), protein (17.8-18.9%), total lipids (1.0-1.5%) and ash (0.9-1.2%) contents. On the other hand, the ventrecha zone presented 25.8% of protein and the major total lipids content (17.1%). The main minerals found in fish muscle were K (183.5-288.6 mg/100 g muscle) and Na (65.1-175.5 mg/100 g). Glutamic acid (3027.6 mg/100 g muscle) was the main amino acid found in fish muscle, which presented 48% of essential amino acids in the protein fraction. Lipids content showed 57.3% of unsaturated fatty acids and 42.7% of saturated fatty acids.

Intracellular lipid binding protein family diversity from Oyster Crassostrea gigas: genomic and structural features of invertebrate lipid transporters

Intracellular lipid binding proteins (iLBPs) play a role in the transport and cellular uptake of fatty acids and gene expression regulation. The aim of this work was to characterize the iLBP gene family of the Pacific oyster Crassostrea gigas, one of the most cultivated marine bivalves in the world, using bioinformatics and molecular biology approaches. A total of 26 different iLBPs transcripts were identified in the Pacific oyster genome, including alternative splicing and gene duplication events. The oyster iLBP gene family seems to be more expanded than in other invertebrates. Furthermore, 3D structural modeling and molecular docking analysis mapped the main amino acids involved in ligand interactions, and comparisons to available protein structures from vertebrate families revealed new binding cavities. Ten different CgiLBPs were analyzed by quantitative PCR in various tissues of C. gigas, which suggested differential prevalent gene expression of CgiLBPs among tissue groups. The data indicate a wider repertoire of iLBPs in labial palps, a food-sorting tissue. The different gene transcription profiles and reported docking systems suggest that the iLBPs are a non-generalist ligand binding protein family with specific functions.

개체동결 굴(Crassostrea gigas)을 이용한 레토르트파우치 굴국의 제조 및 품질특성

To develop a value-added product from individually quick-frozen oysters Crassostrea gigas (IQFO), we prepared a retort pouched oyster soup (RPOS) from IQFOs and characterized its processing conditions and quality metrics. We found that the most appropriate manufacturing process for the RPOS consisted of half-thawing and washing raw IQF oysters, blanching, adding them to the retort pouch along with other ingredients (base soup stock, IQF oyster extract, radish, bean sprouts, garlic, and red pepper), sealing, retort sterilization (<TEX>$120^{\circ}$</TEX>, F0-value 10 min.), cooling, and packaging inspection. The moisture, crude protein, pH and salinity of the RPOS were 91.0%, 2.8%, 6.20 and 0.9%, respectively. The total amino acid content of the RPOS was 2,163.8 mg/100 g, and the main amino acids were glutamic acid, aspartic acid, leucine, proline, lysine and arginine. The primary inorganic ions were Na, K, S and Zn. In taste compounds, total free amino acid content was 313.4 mg/100 g, and the main free amino acids were glutamic acid, taurine, proline, hydroxyproline, aspartic acid, glycine, alanine, valine, lysine and arginine. This RPOS has good storage stability and organoleptic qualities compared with commercial retort pouched shellfish soup, and is suitable for commercialization as a value-added instant seafood soup.

Sectorial land snail damage to the lichen Argopsis friesiana could be explained by metabolite profiles

Notodiscus hookeri is the only native land snail of the sub-Antarctic present in Crozet Archipelago. Two shell ecophenotypes co-exist on Possession Island and feed exclusively on lichens [1] that are symbiotic organisms widely distributed in sub-Antarctic islands. To improve our understanding of lichen-snail trophic interactions, the endemic tripartite lichen Argopsis friesiana was selected. The snail belonging to the organic ecophenotype occurs sympatrically with A. friesiana. Profiling and quantification of the major secondary metabolites in the whole lichen were carried out by LC-DAD-MS. Two main compounds were identified, the depside atranorin (8.2 mg g-1 DM) and the depsidone argopsin. Besides, a screening of primary metabolites was carried out to determine which compounds could be useful for the snail energetic demands. Glutamate, glutamine, gamma-aminobutyric acid and alpha-alanine were the main amino acids found in the lichen in low concentrations (0.4 mg·g-1 DM). Carbohydrates, including arabitol (10.2 mg g-1), mannitol (4.0.10-4 mg g-1) and sucrose (3.0.10-4 mg g-1), were also identified. In cultivation, N. hookeri snails were fed with fructified thalli of A. friesiana. Snails (n = 20) ate the podetia cortex and phyllocladia but they clearly avoided apothecia, the reproductive organs. This sectorial damage of the lichen by the snail suggested a differential distribution of the metabolites. Therefore, a profiling of secondary compounds was performed by Direct Analysis in Real Time – Mass Spectroscopy (DART-MS) [2] on each morphological part of the lichen (phyllocladia, apothecia, podetia and cephalodia). The identification and distribution of secondary metabolites, fatty acids, amino acids and carbohydrates should help us to determine whether metabolites affect snail feeding choice and which of them could be involved.

Molecular epidemiology of Japanese encephalitis viruses isolated in Yunnan province, 1977-2010

Objective: To understand the genetic and molecular epidemiologic characteristics of 63 strains of Japanese encephalitis virus (JEV) isolated in Yunnan province, China during 1977-2010. Methods: Suckling mice were inoculated with viruses continuously and the viral nucleic acid were extracted from the brain-grinding supernatants of the infected and moribund mice, then the gene fragments of E region were amplified by RT-PCR. Bioinformatics (Clustal X, DNAstar, Mega 5.0 and other software) was used to analyze the nucleotide and deduced amino acid sequences and phylogenetic trees. Results: Yunnan strains of JEV could cause illness and deaths in suckling mice. The results of virus nucleic acid detection and sequencing indicated that nucleotide sequences of E gene of the 63 virus strains were obtained. Phylogenetic tree and homology analyses based on E genomes showed that 47 strains of the experimental virus belonged to genotype 1 (G-1) and 16 strains belonged to genotype 3 (G-3). The 47 isolates of G-1 were divided into 2 clades, of them, the earliest isolates of G-1 (M28, 1977 and BN82215, 1982) in Yunnan of China and the early isolates of G-1 (U70416, 1982; DQ084229, the year is unknown) in Thailand were in one clade, and the isolates of G-1 from 2007-2010 in Yunnan could be divided into 2 subgroups. The 16 isolates of G-3 from Yunnan were divided into 3 clades, among them, the isolates from 1970-1990s in Yunnan were in two clades, and the isolates from 2004 in Yunnan were in one clade. In addition, their main amino acid sites of antigenicity, pathogenic, virulence of both G-1 and G-3 had no significant change. Conclusion: JEV G-1 and G-3 co-circulated in Yunnan, and G-1 was predominant. The JEV strains isolated in different years and areas in Yunnan had different molecular epidemiologic characteristics and genetic diversity. The results of this study suggested that JEV G-1 might originate from Yunnan of China and adjacent Southeast Asia region.

Concentration Variation and Removal of Amino Acids in Typical Drinking Sources in the South of China

Amino acids are the main components of nitrogenous organic matter in surface water. In order to reveal the concentration variation and removal of amino acids in reservoirs water, the concentration variation of the twenty common amino acids for three main reservoirs' water in a typical southern city of China was monitored between May and October in the year of 2015 by HPLC, and the space distribution and change trend of the twenty amino acids were analyzed. In addition, the removal of the twenty amino acids was also studied by different water treatment processes. The results showed that the amino acids contents and composition were different among the three reservoirs. Aspartic acid, cysteine and leucine were the main amino acids for the three reservoirs. Besides, there was no obvious seasonal variation of amino acids content for reservoir C. However, the concentration of amino acids in autumn was higher than that in summer. Coagulation and sedimentation were main units for the removal of amino acids in conventional and BAC-UF processes while O3 oxidation was the main unit in O3-BAC process. 94.42%, 66.04% and 49.75% of total amino acids contents were removed by the conventional, BAC-UF and O3-BAC processes, respectively.

Free amino acid profile of Bubalus bubalis L. meat from the Campania region

In this study, we determined the amount of carnosine and anserine in water buffalo meat without hanging treatment and the free amino acid profile by using amino acid analyser with post-column ninhydrin derivatization procedure. The main free amino acids present in samples were glutamic acid (>60 mg/100 g), followed by alanine, glycine, and arginine. Other protein amino acids were detected in minor amounts (less than 2 mg/100 g). Among the non-protein amine-containing compounds, taurine and urea were the most abundant. The analysis showed that 50% of the total free amino acids was represented by dipeptides carnosine (average ~130.3 mg/100 g) and anserine (average ~17.9 mg/100 g). Thus, this study for the first time reports the free amino acids profile of water buffalo meat and the content of carnosine and anserine, potentially involved in the darkening meat process and their ratio, that could be used to estimate the water buffalo meat portion in mixed meat products.

Caffeine alters glutamate–aspartate transporter function and expression in rat retina

l-Glutamate and l-aspartate are the main excitatory amino acids (EAAs) in the Central Nervous System (CNS) and their uptake regulation is critical for the maintenance of the excitatory balance. Excitatory amino acid transporters (EAATs) are widely distributed among central neurons and glial cells. GLAST and GLT1 are expressed in glial cells, whereas excitatory amino acid transporter 3/excitatory amino acid carrier 1 (EAAT3/EAAC1) is neuronal. Different signaling pathways regulate glutamate uptake by modifying the activity and expression of EAATs. In the present work we show that immature postnatal day 3 (PN3) rat retinas challenged by l-glutamate release [3H]-d-Aspartate linked to the reverse transport, with participation of NMDA, but not of non-NMDA receptors. The amount of [3H]-d-Aspartate released by l-glutamate is reduced during retinal development. Moreover, immature retinae at PN3 and PN7, but not PN14, exposed to a single dose of 200 or 500μM caffeine or the selective A2A receptor (A2AR) antagonist 100nM ZM241385 decreased [3H]-d-Aspartate uptake. Caffeine also selectively increased total expression of EAAT3 at PN7 and its expression in membrane fractions. However, both EAAT1 and EAAT2 were reduced after caffeine treatment in P2 fraction. Addition of 100nM DPCPX, an A1 receptor (A1R) antagonist, had no effect on the [3H]-d-Aspartate uptake. [3H]-d-Aspartate release was dependent on both extracellular sodium and Dl-TBOA, but not calcium, implying a transporter-mediated mechanism. Our results suggest that in the developing rat retina caffeine modulates [3H]-d-Aspartate uptake by blocking adenosine A2AR.

β-Catenin signaling positively regulates glutamate uptake and metabolism in astrocytes.

BackgroundNeurological disorders have been linked to abnormal excitatory neurotransmission. Perturbations in glutamate cycling can have profound impacts on normal activity, lead to excitotoxicity and neuroinflammation, and induce and/or exacerbate impairments in these diseases. Astrocytes play a key role in excitatory signaling as they both clear glutamate from the synaptic cleft and house enzymes responsible for glutamate conversion to glutamine. However, mechanisms responsible for the regulation of glutamate cycling, including the main astrocytic glutamate transporter excitatory amino acid transporter 2 (EAAT2 or GLT-1 in rodents) and glutamine synthetase (GS) which catalyzes the ATP-dependent reaction of glutamate and ammonia into glutamine, remain largely undefined.MethodsGain and loss of function for β-catenin in human progenitor-derived astrocyte (PDAs) was used to assess EAAT2 and GS levels by PCR, western blot, luciferase reporter assays, and chromatin immunoprecipitation (ChIP). Further, morpholinos were stereotaxically injected into C57BL/6 mice and western blots measured the protein levels of β-catenin, GLT-1, and GS.Resultsβ-Catenin, a transcriptional co-activator and the central mediator of Wnt/β-catenin signaling pathway, positively regulates EAAT2 and GS at the transcriptional level in PDAs by partnering with T cell factor 1 (TCF-1) and TCF-3, respectively. This pathway is conserved in vivo as the knockdown of β-catenin in the prefrontal cortex results in reduced GLT-1 and GS expression.ConclusionsThese studies confirm that β-catenin regulates key proteins responsible for excitatory glutamate neurotransmission in vitro and in vivo and reveal the therapeutic potential of β-catenin modulation in treating diseases with abnormal glutamatergic neurotransmission and excitotoxicity.

Evaluation of the digestible lysine requirements in female turkeys from 0 to 68 days of age

Over the past years, turkey meat has gained a prominent position in the global market. As lysine (Lys) is among the main essential amino acids (AA) for protein deposition in the carcass, defining Lys requirements can contribute to improving the performance and carcass yield of turkey for meat production. Thus, the objective of this study was to evaluate if the digestible Lys levels proposed by breeder’s guidelines are adequate to achieve the best performance in the used rearing and feed conditions of this study. In each phase, 800 female turkeys of the BUT (British United Turkey) hybrid strain were used. The turkeys were distributed in a completely randomized design in experiment 1 (initial phase: 0–25 d) and in a randomized block design in experiment 2 (growth phase: 26–48 d) and experiment 3 (finishing phase: 49–68 d). The treatments consisted of graded levels of digestible Lys with eight replications of 20 turkeys each. The digestible Lys levels tested were 13.6, 14.5, 15.8, 16.9 and 18.2g/kg in the initial phase; 12.2, 13.2, 14.4, 15.4 and 16.2g/kg in the growth phase; and 9.7, 10.4, 11.4, 12.1 and 13.7g/kg in the finishing phase. The average daily gain (ADG), average daily feed intake (ADFI), feed efficiency (FE) and carcass yield (CY) were evaluated. The ADG, FE and CY data were improved by the digestible Lys levels (P<0.05), and the data were adjusted to the quadratic and broken line functions. The digestible Lys level was estimated by the first intercept of the quadratic function with the plateau of the broken line function. At the end of experiment 3, the CY was evaluated (at 68 d). The digestible Lys level for better ADG and FE were, respectively, 16.69g/kg and 16.55g/kg in the initial phase, 14.25g/kg and 14.15g/kg in the growth phase, and 12.23g/kg and 12.07g/kg in the finishing phase. The digestible Lys level for CY was 12.32g/kg. The current study concludes that digestible Lys levels are in the range of the nutritional guidelines for the strain used, except in the initial phase. Due to the difference in the initial recommendation, these levels should be validated in further investigations through performance trials.

일반과 자색 건조 돼지감자의 식품 성분 및 항산화 활성

본 연구는 일반과 자색 건조 돼지감자의 일반성분, 무기질함량, 유리아미노산 함량, 색도, 항산화 활성을 측정하였다. 돼지감자의 일반성분은 품종과 관계없이 탄수화물, 조단백, 회분, 수분 함량 순으로 높았으며, 색의 차이는 나타나지 않았다. 돼지감자의 품종과 관계없이 가장 높은 무기질은 칼륨이었고, 다음으로 칼슘, 마그네슘, 나트륨, 철분 순으로 나타났다. 일반시료가 자색시료보다 높은 무기질은 칼슘, 마그네슘, 철분, 아연이었고 자색이 일반보다 높은 것은 칼륨, 나트륨, 구리, 망간으로 나타났으나 품종 간의 유의적인 차이는 없었다. 돼지감자에 가장 많이 함유된 아미노산은 품종과 관계없이 arginine이었고, 다음으로 asparagine, aspartic acid, γ-amino-n-butyric acid 순으로 나타났다. 또한, 일반시료보다 자색시료에서 유의적으로(P0.05) 높게 나타난 아미노산은 cystine, leucine, tyrosine이었고, 일반시료가 자색시료보다 유의적으로(P0.05) 높게 나타난 아미노산은 phosphoethanolamine으로 나타났다. 색도의 경우 L, a, b 모두 일반시료보다 자색시료에서 높게 나타났으나 유의적 차이는 없었다. 항산화 활성에서는 방법론 중 ABTS assay를 제외하고는 모든 활성에서 자색시료가 일반시료에 비해 항산화 활성이 높게 나타났다. 일부 FRAP와 ORAC assay의 경우 추출물의 낮은 농도에서는 일반시료와 자색시료 간 차이가 없는 것으로 나타났으며, 자색시료의 경우 높은 농도에서 항산화 활성이 있는 것으로 나타났다.

Labelled microbial culture as a calibration medium for (13) C-isotope measurement of derivatized compounds: application to tert-butyldimethylsilyl amino acids.

Compound-specific stable carbon isotope analysis by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) is widely used in studies of environmental or biological functioning. In the case of derivatized molecules, a calibration might be required due to added non-analyte carbon and in some cases non-stoichiometric recovery by the mass spectrometer. Two biological materials of known isotopic composition were produced by microbial cell cultures on either (13) C-labelled glucose or non-labelled glucose as sole source of carbon. Subsequent hydrolyzed amino acids were derivatized as tert-butyldimethylsilyl (tBDMSi) derivatives and analyzed by GC/C/IRMS. The (13) C-enrichment measurements were used as a direct calibration to calculate the original (13) C/(12) C ratios of individual amino acids. We tested this calibration on both known and unknown samples. For the main proteinogenic amino acids we could determine the number of non-analyte added carbon atoms and assess the non-stoichiometrical recovery of tBDMSi carbon atoms, due to their incomplete oxidation in the combustion step of GC/C/IRMS. The calibration enabled the determination of the natural abundances (δ(13) C values) of amino acids with an average accuracy of ±1.1 ‰. We illustrate the application of the calibration to determine the (13) C/(12) C ratios of amino acids, and the associated uncertainty, in biological and plant materials. The analysis of a labelled microbial cell culture offers a straightforward, rapid and reliable estimate of non-analyte carbon contribution to stable isotope composition. We recommend this method as a calibration or a control in artificial or natural (13) C-tracing experiments. Copyright © 2016 John Wiley & Sons, Ltd.

English

Gelatin extraction process from Kumakuma (Brachyplathystoma filamentosum) skin was optimized using a calcium hydroxide solution. The gelatin obtained was characterized through scanning electron microscopy and analyses of yield, gel strength, color, viscosity, amino acid profile, melting point, foaming capacity, and emulsifying capacity. The optimized conditions were defined over ten days of pre-treatment at 50&deg;C. This condition resulted in desirability of 0.965 and yield and gel strength values of 20.24% and 221 g, respectively. Glycine was the main amino acid both in the fish skin (11.68%) and in the gelatin obtained (23.39%). Gelatin had extendable and consistent gel characteristics and its microstructure showed even threads with small gaps throughout, which is favorable for the food industry. &nbsp; Key words: Residue, fish, pre-treatment, gelatin, gel strength.

Diversité Variétale, Qualité Et Utilisation Du Maïs (Zea Mays) En Afrique De l’Ouest : Revue Critique

Maize (Zea mays) is a cereal cultivated through all the region of the world. Its constitutes one of the cereals the most used for human consumption. The current review focused on the diversity, the nutritional quality and the forms of use of maize in West Africa region. The review allowed to notice that more than twenty varieties of maize were cultivated in Bénin and in the sub-region. With regard to nutritional aspect, those different varieties of maize contained variable amounts of starch (64-78%), fat (4- 6%), protein (7-12%), crude fibers (2-2.5%), ash (1-1.5%) and sugar (1-3%). Potassium (324.8-344 mg /100g), magnesium (107.9-115 mg/100g) and phosphorus (99,6-276 mg/100g) were the main mineral in maize. Likewise, leucine, isoleucine, tryptophane and valine all contained in the germ were the main amino acids in maize. These chemical components can be alone or in a possible synergy of action responsible for numerous technological advantages of maize. Through its chemical and technological characteristics the maize constitutes an important raw material for many culinary recipes in West Africa region. So it is important to make the inventory of the main varieties cultivated in the sub-region, to compare them at both nutritional and technological aspects for prospective actions to undertake in order to improve the yield of these varieties and to guarantee food security for the populations.

Apparent digestibility of nutrients and energy of conventional ingredients for the silver mojarra, Diapterus rhombeus

Knowledge on the nutritional value of feed ingredient is an important step in the formulation of diets in order to maximize animal productivity. Thus a study was conducted to determine the apparent digestibility coefficients (ADC) of dry matter (ADCDM), crude protein (ADCCP), gross energy (ADCGE) and amino acids (ADCAA) of conventional feed ingredients for juvenile silver mojarra (13.0 ± 3.23 g). The study was conducted in the laboratory for nutrition and feeding of fish (AQUANUT), using 80 silver mojarra collected in nature, which were kept in digestibility aquaria for a period of 21 days. The following ingredients were evaluated: fish meal, soybean meal, corn meal, corn gluten meal, rice bran, wheat bran and starch, which substituted 30% of a reference pelletized diet with 325.00 g kg-1 crude protein and 3,692 Kcal kg-1 gross energy. Additionally 1.0 g kg-1 chrome oxide was added to each diet as a marker. The excreta were obtained using three repetitions for each tested ingredient, which were dried for further analyses. The soybean meal showed the best ADCDM value (67.45%), followed by the other ingredients. There was no significant difference between the soybean meal (95.16%), fish meal (92.97%) and the corn meal (91.90%) for the best ADCCP coefficients. The ADCGE for soybean meal and maize meal were 65.23% and 60.31%, respectively, followed by fish meal (51.85%). The results demonstrate that silver mojarra can digest animal protein as well as that of vegetal origin. Silver mojarra can also efficiently digest and absorb some of the main amino acids of fish, such as lysine, methionine and threonine, from the same studied ingredients.