Essential Amino Acid Score Research Articles

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.

Tempeh flour from chickpea ( Cicer arietinum L.) nutritional and physicochemical properties

The effects of solid state fermentation (SSF) on physicochemical and nutritional properties of chickpea flour were studied. Fermented (tempeh) flour showed higher particle size index, gelatinization temperature, dispersability and resistant starch content, and lower gelatinization enthalpy and water solubility than unfermented flour. SSF increased the content of the essential amino acids (EAA) Ile, total sulphur (Met + Cys), total aromatic (Phe + Tyr), and Thr in 37, 41, 107, and 39 g kg −1 protein, respectively; Trp content decreased 8 g kg −1 protein. Total sulphur (EAA score = 0.87) was limiting in unfermented flour and Trp (0.93) in tempeh flour. SSP improved the in vitro and true protein digestibility (72.2–83.2% and 83.7–88.8%, respectively), protein efficiency ratio (PER, 1.59–2.31), cPER (1.54–2.21), and corrected protein digestibility (0.73–0.89). Chickpea tempeh flour may be considered for the fortification of widely consumed legume-based food products.

Composição química e valor protéico do resíduo de soja em relação ao grão de soja

Este trabalho teve por objetivo avaliar a composição química e o valor protéico do resíduo de soja, subproduto do processo de extração do óleo de soja. Determinou-se a composição centesimal, o valor energético e o perfil de aminoácidos do resíduo e do grão de soja. O valor protéico foi avaliado mediante índices biológicos. Ratos Wistar machos, recém-desmamados (n = 24), distribuídos em quatro grupos, foram alimentados por dez dias com rações contendo 10% de proteína (resíduo de soja, soja integral, caseína - controle) ou com ração aprotéica. O resíduo apresentou maior conteúdo protéico (47%) e menor teor energético (334 kcal/100 g) em relação ao grão de soja (40% e 452 kcal/100 g, respectivamente), além de perfil de aminoácidos essenciais com escore de 101% em relação ao padrão de referência e digestibilidade protéica de 88%. Segundo os índices RNPR (Relative Net Protein Ratio) e PDCAAS (escore de aminoácidos corrigido pela digestibilidade), a qualidade da proteína do resíduo de soja é similar à do grão integral (valores protéicos de 87% e 85%, respectivamente). O resíduo de soja é fonte de carboidratos, minerais, fibras e proteína de qualidade nutricional adequada, apresentando vantagens em relação à soja integral tais como menor teor energético e maior concentração protéica.

Nutritional properties of tempeh flour from quality protein maize ( Zea mays L.)

The objective of this investigation was to evaluate physico-chemical and nutritional properties of tempeh flour from a quality protein maize (QPM). In comparison to untreated QPM, the QPM tempeh flour showed a higher ( P ⩽ 0.05 ) gelatinization temperature (81.7 vs 73.9 °C), and resistant starch (4.24 vs 1.9 g/100 g dry flour), and a lower ( P ⩽ 0.05 ) gelatinization enthalpy (1.94 vs 2.74 J/g) and total starch content (56.9 vs 62.6 g/100 g dry flour). The essential amino acids (EAAs) content of raw QPM flour was improved by the solid-state fermentation process. The contents of His, Ile, and Leu increased ( P ⩽ 0.05 ) in 0.81, 0.52, and 1.46 g/100 g protein, respectively. The total sulphur and total aromatic EAAs increased ( P ⩽ 0.05 ) in 0.55 and 3.45 g/100 g protein, respectively. In untreated QPM flour, the first and second limiting EAAs were Lys and Trp, with EAAs score of 0.72. First and second limiting EAAs in QPM tempeh flour were Trp and Lys, with an EAAs score of 0.84. The SSF process increased ( P ⩽ 0.05 ) nutritional indicators as follows: protein efficiency ratio (PER) from 1.78 to 2.10, calculated PER from 1.43 to 1.74, and protein digestibility corrected amino acid score from 0.55 to 0.83. It is concluded that based mainly on its nutritive value, fermented flour may be considered for the fortification of widely consumed cereal-based food product (tortillas, bread, cookies, atoles).

Obtenção e caracterização química e nutricional in vitro das proteínas do soro de sangue bovino

O objetivo principal deste trabalho foi o isolamento e a caracterização química e nutricional (in vitro) das duas principais frações protéicas do soro de sangue bovino. Imediatamente, após coleta higiênica do sangue em matadouro, promoveu-se a coagulação e a remoção da fração celular por centrifugação, em condições apropriadas. A fração globulina (GB) foi precipitada do soro pela saturação a 50% com (NH4)2 SO4 . Após separação da GB por centrifugação a saturação do sobrenadante foi elevada a 80%, para a precipitação da albumina (BSA). A precipitação de proteínas séricas das duas frações somou 98% das proteínas totais do soro. As duas frações protéicas foram caracterizadas quanto à composição centesimal, perfil de aminoácidos, composição mineral, escore de aminoácidos essenciais (EAE), digestibilidade da proteína e PDCAAS ("Protein digestibility corrected amino acid scoring"). O teor de proteína nas duas frações foi de aproximadamente 85% e a BSA se caracterizou pelo elevado teor de lisina, histidina e aminoácidos sulfurados. O EAE para BSA foi 70% sendo triptofano o aminoácido mais limitante e 87,8% para a GB, sendo a isoleucina o aminoácido mais limitante. O uso das técnicas de eletroforese e densitometria permitiu a caracterização das frações quanto ao número de bandas pesos moleculares e proporção relativa entre as várias proteínas.

Nutritional and antinutritional evaluation of raw and processed seeds of a wild legume, Canavalia cathartica of coastal sand dunes of India

Seeds of a wild legume, Canavalia cathartica collected from coastal sand dunes of the southwest coast of India were processed (roasted and cooked) and analyzed for proximate composition, mineral constituents, protein fractions, amino acid profiles, fatty acids and some antinutritional factors. Raw, roasted and cooked seeds contained 35.5%, 30.5% and 29.2% crude protein; 52.8%, 65.3% and 65.4% crude carbohydrates; 1.3%, 1.4% and 1.4% crude lipids; 1.7%, 1.6% and 1% crude fibre and 3.1%, 3% and 3.1% ash, respectively. Among the minerals, potassium was the highest (895, 821 and 190 mg/100 g), followed by phosphorus (137, 112 and 99 mg/100 g) and calcium (84, 70 and 44 mg/100 g). Among the true protein fractions of raw seeds, globulins (18.3 g/100 g) and albumins (7.3 g/100 g) were the major seed proteins. Essential amino acids, threonine, valine, methionine + cystine, isoleucine, leucine, phenylalanine + tyrosine and lysine, were above the FAO/WHO pattern in raw seeds. In roasted and cooked seeds, essential amino acid score ranged between 54 (threonine) and 224 (methionine). Essential amino acids, leucine, phenylalanine and lysine, in raw seeds were more than those of whole egg protein, soybean and rice. Total phenolics slightly declined in cooked seeds. Seeds did not possess tannins and trypsin inhibitors. Proteins of raw seeds possessed strong hemagglutination activity, which was lowered in processed seeds. The current study demonstrated that seeds of C. cathartica were high in protein, essential amino acids and low in saturated fatty acids and anti-nutritional factors.

Efeito do enriquecimento de biscoitos tipo água e sal, com extrato de levedura (Saccharomyces sp.)

The objective of this investigation was to establish the composition of the yeast (Saccharomyces sp.) obtained as a byproduct of the alcoholic fermentation industry, in the form of an autolysate (AT) and their derivatives, extract (Ex) and insoluble fraction (FI). The total autolysate (AT) and the extract (Ex), after dehydration in spray dryer, were utilized as flavour enhancers in salted biscuits. Addition to the biscuits of 5% Ex improved the essential amino acid score (EAE) from 38 to 60%, and the net protein utilization index (NPR) from 1.0 to 2.0 (100%). There was also a significant improvement in the acceptability and preference of the enriched biscuits by the consumers.

Enriquecimento de macarrão tipo tubo (massa curta) com derivados de levedura (Saccharomyces sp.): impacto nutricional e sensorial

Esta pesquisa teve como objetivo investigar a viabilidade técnica e os melhores níveis de adição dos derivados de levedura, autolisado (AT) e extrato (Ex) ao macarrão, visando uma melhoria do valor nutritivo sem diminuir a sua aceitação pelo consumidor. Adição de 5 ou de 7,5% de derivado de levedura melhorou o escore de aminoácidos essenciais (EAE) de 9 e 19%, respectivamente, para o AT e o Ex. O índice que mede a capacidade da proteína de promover crescimento (NPR) se elevou de 25 e 40% para a adição de 7,5% de autolisado ou de extrato, respectivamente. No macarrão massa branca, a adição de 5% de Ex não alterou a aceitação do produto, contudo 5% de AT teve um impacto negativo na aceitação pelo consumidor. A adição à massa de extrato de espinafre (massa verde) de 7,5% de derivado de levedura afetou apenas a aparência do macarrão adicionado de extrato e a aparência e a cor do macarrão com 7,5% de autolisado, em relação ao macarrão contendo apenas extrato de espinafre. A adição de espinafre à massa melhorou as características sensoriais do macarrão adicionado de 7,5% de autolisado. As características tecnológicas de fabricação dos macarrões não foram alteradas pela adição à massa dos derivados de levedura.

Production and Nutritional Evaluation of Liquefied Weaning Foods from Malted Sorghum, Quality Protein Maize, and Other Cereals

ABSTRACTDifferent concentrations of sorghum diastatic malt (SDM) were added to pregelatinized pastes from regular maize flour with the aim of hydrolyzing the starch to produce liquefied foods with 15% solids. Viscosities of the blends decreased as the concentration of SDM increased. Addition of 6.66% SDM based on total amount of solids reduced viscosity by ≈50% when compared with a food that did not contain any SDM. Addition of 33.3 or 46.6% SDM reduced viscosity by ≈70 or 75%, respectively. Most of the reduction in viscosity occurred within 1–3 min of incubation with warm water. Weanling rats were fed a combination 33.3% SDM and 66.6% of either quality protein maize (QPM), regular maize (RMZ) or decorticated pearl millet (DPM) to estimate protein efficiency ratios (PER), protein digestibility, biological value (BV), and net protein utilization (NPU). Rat growth was positively correlated with dietary lysine content and essential amino acid (EAA) scores; therefore, animals fed QPM weanling food had significantly higher (P < 0.05) protein digestibility corrected EAA scores, PER, BV, and NPU than counterparts fed diets based on RMZ or DPM. This demonstrates that it is feasible to produce nutritious liquefied weaning foods blending 33.3% SDM with 66.6% QPM using simple processing techniques.

Aspects of whey protein usage in infant nutrition, a brief review

Summary Demineralized whey, whey protein concentrates and, to a lesser extent, some other whey protein fractions are key raw materials in infant formula manufacture. An estimate of the amount of whey protein used in infant formulae annually is in the order of 30–40 000 tons. Infant formula development has been a long lasting effort to approach the nutrient composition of human breast milk while using cow's milk as the raw material. This required extensive fractionation of the bovine milk followed by subsequent recombination of specific fractions. Criteria to judge protein quality and define adequate protein quantity in infant formulae have also evolved. Early criteria for protein adequacy were based on Protein Efficiency Ratio (PER) testing in rats and/or nitrogen balance studies. More recently, the approach of essential amino acid scores, based on the amino acid pattern of mature human milk has been put forward. Regulatory authorities such as CODEX, EC Commission and more recently LSRO in its suggestions to FDA in the USA, have issued reference amino acid profiles which are based on the average amino acid composition of human milk. The same authorities have also regulated protein density in infant formulae, accounting for an observed protein mean density of 1.5–1.6 g /100 kcal in mature breast milk. The minimum protein level of cow's milk based infant formulae was fixed at 1.8 g/100 kcal by these authorities. Current infant formulae have however protein densities significantly higher than the minimum of 1.8 g/100 kcal. The higher protein density compensates for the likeliness that the protein in the best of the formulae, is not as ideal for the infant as the protein from breast milk. Even if a complete equivalence may be difficult to reach, efforts continue in the direction of further optimizing the protein quality in terms of essential and semi‐essential amino acid profiles. This is the only way to be able to lower the protein content in a formula to levels that are nearer to the low protein density of human milk. Among several possibilities, the increase in the mass proportion of bovine α‐lactalbumin is a particularly promising way to achieve this goal.

Chemical composition of three underutilized legume seeds grown in China

Proteins of Phaseolus angularis, Phaseolus calcaratus and Dolichos lablab seeds (24.9 to 26.5% dry weight) were mainly contributed by their cotyledons which had a proportion of 82.9 to 90.8% by weight of the whole seeds. The levels of all the essential amino acids of the legume seeds (415 to 443 mg g −1 protein) were above the FAO/WHO, (1990) requirement with the essential amino acid scores of the methionine and cystine being 1.02 to 1.19. Appreciable amounts of oligosaccharides of the raffinose family were found mainly in the cotyledons (3.52 to 4.72% dry weight). The total dietary fibre of the legume seeds (13.5 to 19.3% dry weight) consisted predominantly of insoluble dietary fibre (IDF). The cotyledons contained 45.9 to 51.4% dry weight of starch but had low contents of cellulose and lignin. Hulls were highly lignified and consisted predominantly of IDF, with values ranging from 70.7 to 74.0% dry weight. The principal sugar residue analysis revealed that pectins were the major polysaccharide present in the SDF of both the cotyledons and the hulls. While xylans and cellulose were the major polysaccharides present in the IDF of the hulls, xyloglucans and arabinose-rich pectic substances were the principal non-starch polysaccharides in the IDF of the cotyledons.

Chemical evaluation of some lesser known edible mushroom mycelia produced in submerged culture from soy milk waste

The feasibility of using food waste, such as soy milk residue, to produce nutritive fungal biomass was evaluated. Edible mushroom mycelia of Volvariella bombycina, Lyophyllum ulmarius and Pleurotus citrinopileatus were produced in liquid culture containing soy milk waste. The chemical composition of the mushroom mycelia is reported and compared with that of the mushroom fruiting bodies. There were great similarities in the crude protein, lipid, ash and nucleic acid contents between the mycelia and fruiting bodies. Differences were observed in the amount of total dietary fibre and amino acid composition. Lysine was the limiting amino acid found in all mushroom samples. In general, the nutritional quality of the proteins from the mushroom mycelia, as measured by their essential amino acid score, was comparable to those of the fruiting bodies and the FAO/WHO requirement pattern.

Amino acid composition of six varieties of dehulled African yam bean (Sphenostylis stenocarpa) flour

The proximate and amino acids of dehulled African yam bean (Sphenostylis stenocarpa) flour were analysed. The proximate composition showed that both protein and carbohydrate were highly concentrated with values ranging from 20.18 ± 0.02 to 25.78 ± 0.05 g/100 g and 58.46 ± 0.04 to 63.34 ± 0.05 g/100 g respectively while the crude fat, total ash and moisture contents were low. Amino acid analysis showed that the protein contained nutritionally useful quantities of most of the essential amino acids including sulphur-containing amino acids. The total essential amino acids amounted to an average of 53.75% (with histidine) while the TEAA without histidine amounted to 49.64% on average. Both the total amino acids and the total essential amino acids showed no significant difference among the six varieties analysed. However, significant difference occurred among the essential amino acid scores at P < 0.05. The limiting amino acids were also found to be a function of the African yam bean varieties. All determinations were in triplicate.

Biological and chemical evaluation of chick pea seed proteins as affected by germination, extraction and alpha-amylase treatment.

The effects of germination, extraction (double extraction with 70% ethanol and water at isoelectric point) and alpha-amylase treatments of chick pea seed flours on crude protein, total carbohydrate, protein efficiency ratio (PER), biological value (BV), true digestibility (TD), net protein utilization (NPU), essential amino acid composition, in-vitro protein digestibility (IVPD) and actual amino acid indices (essential amino acid index or amino acid score) were evaluated. Crude protein content was increased (8-149%), while total carbohydrate was decreased (11-62%) by germination, extraction and alpha-amylase treatments. Alpha-amylase treatment was more efficient in reducing total carbohydrate and increasing the protein content than that of extraction treatment. The protein quality of chick pea flours as measured by PER, BV, TD, NPU, IVPD and corrected amino acid indices (actual amino acid indices x IVPD) was significantly improved by these treatments. The protein quality of germinated-alpha-amylase treatment was comparable with casein, while germinated-alpha-amylase treaded seeds appeared nutritionally superior to casein. The results indicate that the germinated-alpha-amylase and germinated-alpha-amylase-extracted treatments could be used successfully as a source of concentrated high quality protein for baby food production. The corrected amino acid indices gave better prediction of PER, BV, TD and NPU (r = 93 to 97) than actual amino acid indices (r = 45 to 71). PER was highly correlated with corrected amino acid score (r = 0.93). The PER could be predicted from the following simple regression equation: PER = -1.827 + 0.0561 x corrected amino acid score.

Automatic calculation for the renal failure diet

A logical scheme for algorithm for computation of the renal failure diet is presented along with its application to a programmable calculator. The program is user-interractive; the user may add or delete foods without re-entering previous data. Program outputs include water, protein, calories, carbohydrate, sodium, potassium, calcium, phosphorus, and the essential amino acids (EAA) in absolute and percentage terms. As an index of relative protein quality, the chemical score is computed on a meal-by-meal basis. Individual EAA scores are available to permit designation of the limiting EAA of a meal. A major benefit of the program is the ability to explore and document rapidly a wide variety of meal plans. Improvements in "user-friendliness" will facilitate application with patients.

CHEMICAL COMPOSITION OF WILD RICE GRAIN

Twelve samples of Canadian lake and paddy wild rice (Zizania aquatica L.) were analyzed for proximate, mineral and amino acid composition. Mean proximate and mineral values for lake and paddy wild rice were: total carbohydrate 82.8%, protein (nitrogen × 5.7) 13.8%, ash 1.7%, crude fiber 1.2%, ether extract 0.5%, phosphorous 0.28%, potassium 0.30%, magnesium 0.11%, iron 17 ppm, manganese 14 ppm, zinc 51 ppm and copper 13 ppm. Amino acid composition of the unprocessed wild rice showed little variation among samples. The essential amino acid score of the unprocessed wild rice, based on the FAO/WHO 1973 pattern, was 82, with threonine and lysine most limiting. Lysine values were lowered by processing. Calculated nitrogen-to-protein conversion factors were 5.60 for Johnson strain and 5.65 for lake-grown wild rice.

The Influence of Growing Temperature on the Amino Acid and Nucleic Acid Concentrations of Potato Tubers1

Abstract Seven experimental selections and one commercial cultivar of potato (Solanum tuberosum L.) were grown in moderate (22/18°C, day/night) and cool (11/7°, day/night) regimes to determine the influence of temperature on potato tuber nitrogen, amino acid, and nucleic acid levels. Tubers from low temperatures had higher percentages of rRNA and lower levels of alpha-keto acids. Moderate and cool grown tubers of the same genotype exhibited slightly different gel electrophoretic banding patterns in 88% of the samples, evidence that tuber protein composition was altered. Glutamate, from HCl hydrolysates, was higher in cool grown tubers. Most cool grown tubers were higher in Kjeldahl nitrogen, due in part to higher levels of glutamate family amino acids, i.e. glutamate, proline and arginine. The free amino acids, histidine and arginine were higher in the cool grown tubers. The essential amino acid scores of leucine, isoleucine, lysine, threonine and valine and the amino acid patterns of methionine were significantly lower in the cool grown tubers; consequently, the cool grown tubers were nutritionally inferior per unit of tuber nitrogen.