Analysis Of Amino Acid Profiles Research Articles

Proximate Analysis Of Castor Seeds And Cake

Castor seed obtained from Ilorin was evaluated analytically using its un-decorticated and decorticated full-fat and cake forms for chemical composition and nutritional constituents. Proximate analyses of un-decorticated and decorticated seeds and cake revealed that both the oil seed and cake contain valuable nutrients namely soluble carbohydrate: seed-7.96, cake-24.69, protein: seed-20.78, cake-31.06, fat: seed-51.20, cake-19.40, mineral matter: seed-7.75, cake-11.10 for undecorticated castor seeds and cake respectively. Thedecorticated seed cake gave higher values of these nutrients than the un-decorticated, for instance carbohydrate: seed-8.86, cake-24.88, nitrogen: seed-21.87, cake-35.43, ether extract: seed-55.50, cake-25.10, total ash: seed- 9.40, cake-7.14. Amino acid profile analysis of un-decorticated and decorticated seed and cake compared with soybeans as standard plant protein indicated that the cake is deficient in some indispensable amino acids like lysine (4.11), iso-leucine (3.09), tryptophan (0) compared with 6.30, 7.90 and 1.30 lysine, iso-leucine and tryptopha in soybeans respectively.Based on results of the analyses, it is observed that the seed and cake containvaluable nutrients especially when decorticated and may serve useful alternatives to food/feedstuffs if the castor seed is detoxified of the phytotoxins, ricin (a toxic protein), ricinine (a relatively harmless protein), hydrocyanides and allergens, the extremely potent toxins.

Metabolomic screening and star pattern recognition by urinary amino acid profile analysis from bladder cancer patients

Metabolomic analysis of urinary amino acids (AAs) from patients with bladder cancer was performed by gas chromatography–mass spectrometry. The β-aminoisobutyric acid (P < 0.05) and pyroglutamic acid (P < 0.03) levels among 21 AAs had relatively low P-values in the cancer group. The distorted star pattern of the cancer group was different from the heneicosagonal shape of the control mean. The present metabolomic screening combined with star pattern recognition method as clinical monitoring tool might be useful for the visual discrimination of bladder cancer group from normal group.

Evaluation of the Botanical Origin of Estonian Uni- and Polyfloral Honeys by Amino Acid Content

The free amino acid content of 61 honey samples from Estonia has been determined by HPLC-UV with precolumn derivatization with diethyl ethoxymethylenemalonate. Analyzed samples were seven types of unifloral honeys and polyfloral honeys. The main amino acids found in Estonian honeys were proline and phenylalanine. The resulting data have been analyzed by t test and principal component analysis (PCA). t Test revealed that some amino acids (alpha-alanine, beta-alanine, asparagine, gamma-aminobutyric acid, glutamine, glycine, histidine, ornithine, phenylalanine, proline, serine, and tryptophan) are more potent for assigning honey botanical origin than others. PCA enabled differentiation of some honey types by their botanical origin. In the space of the two first principal components, heather honeys form a cluster that is clearly separable from, for example, polyfloral honeys. It is concluded that analysis of the free amino acid profile may serve as a useful tool to assess the botanical origin of Estonian honeys.

Determination of microbial community structures of shrimp floc cultures by biomarkers and analysis of floc amino acid profiles

Simple, rapid and reliable methods are required to monitor the microbial community change in aquatic pond for better animal performance. Four floc (suspended organic matter) samples were collected from outdoor raceways and tanks used for culturing Pacific white shrimp Litopenaeus vannamei. Twenty-two chlorophyll (Chl) and carotenoid pigments were separated, identified and quantified using high-performance liquid chromatography–ultraviolet/Vis-mass spectrometry in the freeze-dried floc samples. Algal community composition (diatoms, chlorophytes, cyanobacteria, dinoflagellates and cryptophytes) was determined by measuring concentrations of the respective taxonomic biomarkers (carotenoid fucoxanthin, lutein, zeaxanthin, peridinin and alloxanthin) as independent variables and Chl a as the dependent variable using a multiple regression model. This analysis found that the phytoplankton community of the floc samples from two groups of shrimp tanks (32 g L−1-salinity) were diatom-dominated (81.7% and 84.4%); and two floc samples from shrimp raceways (5 and 18 g L−1-salinity) were chlorophyte-dominated (75.4% and 82.3%). Assessment of total algal and bacterial biomass by quantification of Chl a and muramic acid, respectively, indicated that the 18 g L−1-salinity raceway sample was bacteria-dominated, whereas the other three floc samples were algae-dominated. Sample protein quality was evaluated by its essential amino acid (AA) score and index. Arginine and lysine were found to be the two most limiting AAs for all floc samples.

Lysine biosynthesis and nitrogen metabolism in quinoa ( Chenopodium quinoa): Study of enzymes and nitrogen-containing compounds

Aspartate kinase (AK, EC 2.7.2.4), homoserine dehydrogenase (HSDH, EC 1.1.1.3) and dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) were isolated and partially purified from immature Chenopodium quinoa Willd seeds. Enzyme activities were studied in the presence of the aspartate-derived amino acids lysine, threonine and methionine and also the lysine analogue S-2-aminoethyl- l-cysteine (AEC), at 1 mM and 5 mM. The results confirmed the existence of, at least, two AK isoenzymes, one inhibited by lysine and the other inhibited by threonine, the latter being predominant in quinoa seeds. HSDH activity was also shown to be partially inhibited by threonine, whereas some of the activity was resistant to the inhibitory effect, indicating the presence of two isoenzymes, one resistant and another sensitive to threonine inhibition. Only one DHDPS isoenzyme highly sensitive to lysine inhibition was detected. The results suggest that the high concentration of lysine observed in quinoa seeds is possibly due to a combined effect of increased lysine synthesis and accumulation in the soluble form and/or as protein lysine. Nitrogen assimilation was also investigated and based on nitrate content, nitrate reductase activity, amino acid distribution and ureide content, the leaves were identified as the predominant site of nitrate reduction in this plant species. The amino acid profile analysis in leaves and roots also indicated an important role of soluble glutamine as a nitrogen transporting compound.

Amino acid profiling in urine by capillary zone electrophoresis – mass spectrometry

Analysis of amino acid profiles in urine and plasma is an essential part of modern clinical diagnostic routine. Here we present an approach for the analysis of amino acids in urine by capillary electrophoresis/time-of-flight (TOF) mass spectrometry. At first a method combining improved separation, high dynamic range, and high sensitivity is presented. Detection limits in the mid nM-range are achieved through the use of pH-mediated stacking injection in combination with modern TOF detection technology. The method can be easily applied to detect differences in the amino acid profile in urine in a clinical context. Moreover, beside amino acids low molecular weight amines, peptides and related metabolites can be profiled. As a proof of concept, urine samples from patients suffering from osteoarthritis have been analyzed. Finally, the introduction of multivariate data analysis in the work flow was evaluated on spiked urine samples and real clinical material.

FORMATION OF TASTE AND ODOR COMPOUNDS DURING PREPARATION OF DOUCHIBA, A CHINESE TRADITIONAL SOY-FERMENTED APPETIZER

Douchiba (DCB), a Chinese traditional soy-fermented appetizer, is abundantly produced and widely consumed in Guizhou province of southwest China. In this study, an analysis of free amino acid (FAA) profiles, low-molecular weight peptide fractions (LMWPFs), hydrophobic bitter peptide fractions (HBPFs) and volatile compounds was conducted to understand the changes in taste and odor compounds of DCB during five consecutive manufacturing stages: steamed soybean (SS), 5-day incubated Koji (Koji), 6-month fermented Douchi, semifinished Douchiba (sm-DCB) and 6-month ripened finished Douchiba (DCB). The total free amino acids (TFAAs) increased significantly from SS to DCB by about 11 times and amounted to 20.1% of the crude protein. Arg, Glu, Phe, Leu and Lys were the most abundant FAA at the end of ripening, and were 64.6% of TFAA. The most abundant taste active FAA classes were the bitter FAA, representing eight- and threefold increases over sweet and MSG-like FAA, respectively. The final values of all bitter and monosodium glutamate-like (MSG-like) FAA at DCB stage were significantly higher than their respective thresholds. The of oligopeptides (500∼1000 Da) accounted for 13.8 and 2.5% of LMWPF and HBPF, respectively. However, the taste of DCB was predominated by saltiness, followed by moderate umami taste and slight bitterness, likely as a result of the and interaction among different taste components. A total of 122 volatile compounds were identified, including alcohols, acids, esters, aldehydes, ketones, phenols, sulfur-containing compounds, heterocyclic compounds, alkines, benzenes and spice aromatics. The subtle aroma of the finished DCB seemed to depend not only on particular key compounds but also on a critical balance or a weighted concentration ratio of 60 compounds. These volatile compounds, mainly derived from lipid oxidation, amino acid degradation, carbohydrate fermentation, Maillard reaction and Strecker degradation during the microbial metabolism, enzymatic catalysis and spontaneous reactions.

Role of Glutamine Depletion in Directing Tissue-specific Nutrient Stress Responses to L-Asparaginase

Role of Glutamine Depletion in Directing Tissue-specific Nutrient Stress Responses to L-Asparaginase

Amino acid profiles of Diplodus sargus (L., 1758) larvae: Implications for feed formulation

The indispensable AA profile of fish carcass has been commonly used as a good indicator of fish amino acids requirements. Amino acid composition of the whole body tissue of Diplodus sargus was determined for the larval ages of 0, 2, 5, 8, 12, 17, 25, 35 and 45 days after hatching (DAH). No significant differences were found during this species ontogeny, except for phenylalanine. A comparative analysis of amino acid profiles from larvae and respective diet was performed. Low correlation was found to rotifers ( R 2 approximately 0.5), while higher correlations were found for Artemia nauplli, metanauplii ( R 2 approximately 0.8) as well as for the dry feed. These results suggest that D. sargus are subjected to higher nutritional imbalances during the first 10 days of feeding when larvae are fed on rotifers alone. Arginine, threonine, lysine, cysteine and histidine appeared to be limiting amino acids at 2, 12, 25 and 45 DAH, respectively. Similar results were reported in literature for Sparus aurata and Solea senegalensis, although D. sargus diets seem to have more amino acids in deficiency as well as more severe differences between larval and diet amino acid profiles. To solve these apparent nutritional imbalances, amino acid supplementation should be considered. The use of inert diets in early larvae ages seems to be most adequate as live feed supplementation appears to be more difficult.

Plasma L-arginine concentration and follicular maturation

Plasma L-arginine concentration and follicular maturation

Diet development and evaluation for juvenile abalone, Haliotis asinina: protein/energy levels

Juveniles of abalone, Haliotis asinina with mean initial weight and shell length of 0.6±0.03 g and 15±0.07 mm were fed practical diets for 90 days. The practical diets contained graded levels of protein from fish meal, shrimp meal, and soybean meal at 22 (diet 1), 27 (diet 2), and 32% (diet 3) with corresponding estimated metabolizable energy values of 3254, 3150, and 3090 kcal ME/kg diet. The amino acid profile and proximate analyses of muscle meat of the test animal and published nutrient requirements of other species of Haliotids were used as a basis for formulating and developing these practical diets. The diets were fed to abalone at 2–5% body weight once daily (1600 h) for biological evaluation in terms of weight gain (WG), increase in shell length (SL), specific growth rate (SGR), protein efficiency ratio (PER), feed conversion ratio (FCR) and for physical evaluation in terms of shell coloration of the animal. Natural food, Gracilariopsis bailinae (17% CP/2200 kcal ME/kg) (NF) fed ad libitum served as the control. Better growth rates, in terms of WG and SL, FCR and PER were noted in abalone fed the three formulated diets compared with those fed seaweed, G. bailinae. Abalone fed diets 3 (WG: 347%; SGR: 0.81; SL: 140%) and 2 (WG: 307%; SGR: 0.70; SL: 139%) showed significantly better growth rate than those fed diet 1 (WG: 252%; SGR: 0.51; SL: 132%). Natural food-fed abalone had the lowest WG (134%), SGR (0.06) and increase in SL (77%). Survival was generally high at 85–95% for all treatments. FCR (1.5–2.3) and PER (2.19–2.47) for animals fed the three diets were significantly better than for those fed natural food (0.10 PER and 6.98 FCR). Regression analysis showed the optimum protein level for juvenile abalone to be 27% with an energy level of 3150 kcal/kg ME. Abalone juveniles fed the formulated diets produced shells with light bluish green color while those fed seaweed retained the original brown color. Diet 2 which contained 27% protein, 5% lipid and 40% carbohydrates with an energy value of 3150 kcal/kg ME may be used as a basal diet for the rearing of juvenile abalone, H. asinina.

Fractionation of casein hydrolysates using polysulfone ultrafiltration hollow fiber membranes

The objective of this study was to characterize the fractionation profile of casein hydrolysates obtained with polysulfone hollow fiber ultrafiltration membranes. The two-step ultrafiltration process developed by Turgeon and Gauthier [J. Food Sci., 55 (1990) 106] was used: a caseinate solution was submitted to proteolysis with chymotrypsin or trypsin, and the reaction mixture (RM) was subsequently ultrafiltered using a 30 kDa (MWCO) hollow-fiber polysulfone membrane. The total hydrolysate permeating from this first step was further fractionated using a 1 kDa (MWCO) membrane, producing the mixture of polypeptides (retentate) and the amino acid fraction (permeate). The effect of enzyme specificity and of membrane retentivitiy on the total composition (total nitrogen, fat, lactose, minerals) and amino acid profile of the fractions was studied. The overall composition of the fractions was not significantly affected by the nature of the enzyme but the degree of hydrolysis and the molecular weight distribution profile analyses showed a marked effect of the enzyme specificity, with trypsin giving a larger proportion of small peptides (< 200 Da) in the mixture of polypeptides. Amino acid profile analyses provided useful information on the phenomena governing the fractionation of amino acids with a polysulfone membrane: (1) the target amino acids of the enzyme are concentrated in the permeate as a result of their presence in all peptides produced by hydrolysis, (2) polar amino acids are retained by the membrane, (3) non-polar amino acids are not selectively rejected by the membrane. Our results suggest that the charge/hydrophobicity balance of the peptides produced is the predominant factor determining the fractionation of casein hydrolysates.

Li Chang-lian et al. An analysis of serum free amino acid profiles in severely burned patients. (Chinese) Chin. J. Plast. Surg. Burns 6

Li Chang-lian et al. An analysis of serum free amino acid profiles in severely burned patients. (Chinese) Chin. J. Plast. Surg. Burns 6

Age-dependent effects of growth hormone on striped bass hybrids

1. 1. The age-dependency of the effects of growth hormone on striped bass hybrids was investigated. 2. 2. The growth enhancement was higher in yearlings than in juveniles after weekly injection of the hormone. 3. 3. The analysis of total protein, RNA, DNA and amino acid profile in the muscle tissue indicated hormonestimulated hypertrophic growth and a possible need for essential amino acid supplementation in diet. 4. 4. Feeding rate was not stimulated whereas food conversion efficiency and intestinal amino acid absorption rate were significantly increased by the hormone treatment in an age-dependent manner. 5. 5. Possible reasons for these observations are discussed.

Fluorometric assay of amino acids and amines by use of 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole(NBD-F) in high-performance liquid chromatography

The reaction of a newly developed fluoregenic reagent, 7-fluoro-4-nitrobenzo-2-oxa-1,3-diazole(NBD-F), with amino acids and biogenic amines was investigated. NBD-F was reactive to both primary and secondary amines including amino acids and biogenic amines such as catecholamines. The amino acids were reacted with the reagent, separated by high-performance liquid chromatography on μ-Bondapak C18 and detected at 10 to 100 fmol level. A few μg of protein hydrolysates, rabbit pyruvate kinase M1, rabbit aldolase A and papain, were adequate for the amino acids quantitation. An automatic amino acid analyzer with fluorometric detection by the post-column derivatization with NBD-F enabled the amino acid profile analysis in blood samples present in a paper disc of 3 mm diameter.