Essential Amino Acid Pattern Research Articles

Protein Quality and Sensory Perception of Hamburgers Based on Quinoa, Lupin and Corn.

The need for partial or total substitution of animal protein sources by vegetable sources of high protein quality with good sensory acceptance is a promising alternative. The objective was to develop a hamburger with vegetable protein using a mixture design based on quinoa (Chenopodium quinoa Willd.), Peruvian Andean corn (Zea mays) and Andean lupine (Lupinus mutabilis Sweet). The design of these mixtures allowed obtaining eleven formulations, three of which were selected for complying with the amino acid intake for adults recommended by FAO. Then, a completely randomized design was applied to the selected samples plus a commercial product. Proximal composition was measured on a dry basis (protein, fat, carbohydrates, and ash), calculation of the Protein Digestibility Corrected Amino Acid Score (PDCAAS) and a sensory analysis was carried out using the Check-All-That-Apply (CATA) method with acceptability in 132 regular consumers of vegetarian products. Protein, fat, carbohydrate, and ash contents ranged from 18.5-24.5, 4.1-7.5, 65.4-72.1 and 2.8-5.9%, respectively. The use of Andean crops favored the protein content and the contribution of sulfur amino acids (SAA) and tryptophan from quinoa and lysine and threonine from lupin. The samples with Andean crops were described as easy to cut, soft, good, healthy, legume flavor, tasty and light brown, however the commercial sample was characterized as difficult to cut, hard, dark brown, uneven color, dry and grainy. The sample with 50% quinoa and 50% lupin was the most acceptable and reached a digestibility of 0.92. It complied with the lysine, threonine, and tryptophan intake, with the exception of SAA, according to the essential amino acid pattern proposed by the Food and Agriculture Organization of the United Nations.

Essential and Non-Essential Amino Acids in Dogs at Different Stages of Chronic Kidney Disease.

Simple SummaryHuman patients affected by chronic kidney disease reported alterations of serum amino acid pattern, as a consequence of several metabolic complications of the renal disease. Our study aimed to evaluate possible differences in serum pattern of essential and non-essential amino acids between dogs with chronic kidney disease and clinically healthy subjects. Canine chronic kidney disease resulted in an association with a significant serum deficiency of the majority of both essential and non-essential amino acids. The amino-acidic disorder was particularly evident when protein-energy wasting syndrome was present, suggesting a potential key role of pathological conditions, such as inflammation, insulin resistance, and increased protein breakdown.Abnormalities of serum amino acid profile, mostly characterized by a reduction in essential amino acids (EAAs) and an increase in non-essential amino acids (NEAAs), have been documented in human chronic kidney diseases (CKD). Amino acid disorders have been associated with CKD complications, such as metabolic acidosis and malnutrition. The aim of the present study was to evaluate EAAs and NEAAs in dogs affected by CKD at different IRIS stages, with particular reference to calcium–phosphate abnormalities, metabolic acidosis, and protein-energy wasting syndrome (PEW). Serum EAAs (L-histidine, L-isoleucine, L-leucine, L-lysine, methionine, L-phenylalanine, L-threonine, tryptophan, L-valine, and L-arginine) and serum NEAAs (L-alanine, L-aspartic acid, L-cysteine, L-glutamic acid, glycine, proline, L-serine, and L-tyrosine) were analyzed with HPLC in a group of dogs with CKD (n = 62), and in a group of healthy dogs (n = 25). CKD dogs showed significantly lower serum levels of histidine (p < 0.000), isoleucine (p < 0.000), tryptophan (p < 0.000), alanine (p = 0.013), cysteine (p < 0.000), and serine (p = 0.002), and significantly higher levels of proline (p < 0.000), leucine (p = 0.001), lysine (p < 0.000), valine (p < 0.000), arginine (p = 0.002), glutamic acid (p = 0.002), and glycine (p = 0.010) compared to healthy dogs. Dogs with abnormal calcium x phosphate values showed significantly higher levels of cysteine (p = 0.003), and lower levels of tryptophan (p = 0.025) compared to CKD dogs with normal CaxP. Dogs with metabolic acidosis showed significantly higher levels of phenylalanine (p = 0.035) and leucine (p = 0.034) compared to CKD dogs without metabolic acidosis. Dogs with PEW showed significantly lower levels for most of amino acids. In PEW dogs, the median distribution of both EAAs (p = 0.000) and NEAAs (p = 0.001) was significantly lower. The serum pattern of both EAAs and NEAAs was significantly different in CKD dogs compared to healthy dogs, although no association with the progression of the IRIS stage was found.

The "ideal protein" concept is not ideal in animal nutrition.

Amino acids (AAs) are required for syntheses of proteins and low-molecular-weight substances with enormous physiological importance. Since 1912, AAs have been classified as nutritionally essential amino acids (EAAs) or nonessential amino acids (NEAAs) for animals. EAAs are those AAs that are either not synthesized or insufficiently synthesized de novo in the organisms. It was assumed that all NEAAs (now known as AAs that are synthesizable in animal cells de novo [AASAs]) were formed sufficiently in animals and were not needed in diets. However, studies over the past three decades have shown that sufficient dietary AASAs (e.g. glutamine, glutamate, glycine, and proline) are necessary for the maximum growth and optimum health of pigs, chickens, and fish. Thus, the concept of “ideal protein” (protein with an optimal EAA pattern that precisely meets the physiological needs of animals), which was originally proposed in the 1950s but ignored AASAs, is not ideal in animal nutrition. Ideal diets must provide all physiologically and nutritionally essential AAs. Improved patterns of AAs in diets for swine and chickens as well as zoo and companion animals have been proposed in recent years. Animal-sourced feedstuffs supply abundant EAAs and AASAs (including glutamate, glutamine, glycine, proline, 4-hydroxyproline, and taurine) for diets of swine, poultry, fish, and crustaceans to improve their growth, development, reproduction, and health, while sustaining global animal production. Nutritionists should move beyond the “ideal protein” concept to consider optimum ratios and amounts of all proteinogenic AAs in diets for mammals, birds, and aquatic animals, and, in the case of carnivores, also taurine.

Estimation of the ideal dietary essential amino acid pattern for pacu (Piaractus mesopotamicus) in the later-juvenile growth phase

This study aimed to estimate the ideal pattern of dietary essential amino acids (EAAs) for pacu ( Piaractus mesopotamicus ) in the later-juvenile growth phase (weighing 460–560 g) by the amino acid (AA) deletion method. A total of 231 pacu in the later-juvenile growth phase (with initial average body weight of 460 ± 4.65 g) were equally distributed in a completely randomized design among 33 fiber tanks of 1000-L (7 fish per tank) in a closed water recirculation system. The trial consisted of 11 treatments including a control diet (CD) and 10 EAA-deficient diets (DDs), with three replicates (tanks) per treatment. The CD consisted of 45% synthetic amino acids and purified feed ingredients and 55% non-purified conventional feed ingredients. The 10 DDs represented the same nutritional composition of the CD but each DD was maintained deficient in 45% of the respective test EAA. During the 60-day experimental duration, fish were fed with extruded diets three times a day until apparent satiation. The present results revealed that fish fed with CD showed better growth performance, feed utilization and body N deposition as compared to DDs. The ideal pattern of dietary EAAs was estimated through the relationship between body nitrogen retention and the amount of amino acid deleted from the control diet. Based on the deletion method, the ideal pattern of dietary EAAs for pacu in the later-juvenile growth phase (expressed relative to lysine requirement of 100%) was estimated as: arginine (84.33%); phenylalanine (55.21%); histidine (29.52%); isoleucine (55.06%); leucine (73.82%); methionine (24.86%); threonine (46.08%); tryptophan (10.42%); and valine (57.00%). • Deletion method can efficiently estimate the ideal EAA pattern for pacu in the later-juvenile • growth phase • 2: Estimation of ideal ratios of EAAs is required for obtaining maximum performance of fish • 3: Diets with ideal EAA ratios may optimize the feed utilization efficiency of fish • 4: Estimation of ideal EAA profiles could help to economize the protein content of feed

Evaluation of the optimum dietary essential amino acid pattern for adult pacu (Piaractus mesopotamicus)

The optimum levels of essential amino acids (EAAs) are required to be maintained in fish feed for obtaining normal body protein synthesis and muscle growth. This study aimed to determine the optimum dietary EAA pattern for adult pacu (Piaractus mesopotamicus) by the amino acid (AA) deletion method. A total of 165 adult fish of 1109.83 ± 14.26 g (initial body weight ± standard deviation) were equally distributed among 11 treatments in a recirculation aquaculture system. Each of the 11 treatments consisted of three randomly arranged replicates (tanks) and 5 fish were stocked per tank. During the 60-day experimental period, fish were fed with 11 diets including a control diet (CD) and 10 EAA limiting diets (LDs) two times daily until apparent satiation. The body nitrogen (N) retention and weight gain in fish fed with EAA LDs was lower (P < 0.05) than the CD. The feed efficiency in fish fed with CD was similar (P > 0.05) to most EAA LDs, except arginine and histidine LDs. The specific growth rate in fish fed with tryptophan, arginine and histidine LDs was different (P < 0.05) as compared to the CD. Based on the present N retention data obtained through the AA deletion method, the optimum pattern of dietary EAAs estimated in relation to lysine requirement (100%) was as follows: arginine 72.16%; phenylalanine 40.83%; histidine 30.15%; isoleucine 53.01%; leucine 81.71%; methionine 24.97%; threonine 58.20%; tryptophan 9.13% and valine 54.69%.

Nutritional evaluation of whole soybean curd made from different soybean materials based on amino acid profiles

AbstractObjectivesAmino acid profiles of whole soybean curds (WSCs) and conventional soybean curds (CSCs) were comparatively studied to 1., evaluate their nutritional value and 2., study the suitable soybean material to fabricate WSCs.Materials and MethodsNine types of soybean materials were selected to make WSCs and CSCs. Protein digestibility-corrected amino acid score (PDCAAS) and principal component analysis were selected to perform the comparative analysis of amino acid profiles of the products.ResultsTotal contents of amino acids in WSCs and CSCs were 41.24–54.87 mg/g and 27.77–36.82 mg/g. Content ranges of essential amino acids were 13.59–19.38 mg/g and 8.46–11.76 mg/g for WSCs and CSCs. The essential amino acid pattern of WSCs was basically close to amino acid pattern spectrum requirements except valine and sulfur amino acids. As a limiting amino acid, methionine represented less than 0.4 for PDCAAS in all soybean curds except WSCs made from relay-cropping Nandou12 and Nandou25.ConclusionsThe overall quality of amino acids in WSCs was higher than that in CSCs, indicating that WSCs indeed exhibited higher nutritional value than CSCs from the viewpoint of amino acid profile. WSCs with the high nutritional value could be made using Nandou25 and relay-cropping Nandou12 as materials.

Nonessential amino acid usage for protein replenishment in humans: a method of estimation

Essential amino acids (EAAs) are key factors in determining dietary protein quality. Their RDAs have been estimated. However, although nonessential amino acids (NEAAs) are utilized for protein synthesis too, no estimates of their usage for body protein replenishment have been proposed so far. The aim of this study was to provide minimum, approximate estimates of NEAA usage for body protein replenishment/conservation in humans. A correlation between the pattern of both EAAs and NEAAs in body proteins, and their usage, was assumed. In order to reconstruct an "average" amino acid pattern/composition of total body proteins (as grams of amino acid per gram of protein), published data of relevant human organs/tissues (skeletal muscle, liver, kidney, gut, and collagen, making up ∼74% of total proteins) were retrieved. The (unknown) amino acid composition of residual proteins (∼26% of total proteins) was assumed to be the same as for the sum of the aforementioned organs excluding collagen. Using international EAA RDA values, an average ratio of EAA RDA to the calculated whole-body EAA composition was derived. This ratio was then used to back-calculate NEAA usage for protein replenishment. The data were calculated also using estimated organ/tissue amino acid turnover. The individual ratios of World Health Organization/Food and Agriculture Organization/United Nations University RDA to EAA content ranged between 1.35 (phenylalanine+tyrosine) and 3.68 (leucine), with a mean±SD value of 2.72±0.81. In a reference 70-kg subject, calculated NEAA usage for body protein replenishment ranged from 0.73 g/d for asparagine to 3.61 g/d for proline. Use of amino acid turnover data yielded similar results. Total NEAA usage for body protein replenishment was ∼19 g/d (45% of total NEAA intake), whereas ∼24 g/d was used for other routes. This method may provide indirect minimum estimates of the usage of NEAAs for body protein replacement in humans.

Molecular Identification of Green Algae, Spirogyra Porticalis, along Parts of River Kaduna and its Potential for Singlecell Protein (SCP) Production

The freshwater alga spirogyra porticalis, a filamentous chlorophyte, was collected and identified on the basis of morphology and molecular characteristics. The nutritional composition of the Alga (protein, carbohydrate, moisture, fat, ash) were determined using the AOAC, Official Methods of Analysis. The components of Single Cell Protein (SCP) were determined using method of proximate analysis. The total content of protein (% dry weight) ranged from 12.46-16.89%, carbohydrate from 34.72-39.25%, moisture from 12.97-16.75%, fat from 20.17-22.03%, ash from 10.78-15.98%. The result revealed that this Macroalga has an appreciable amount of protein, carbohydrate, moisture, fat, and ash. Amino acids composition determines the protein quality of Algae. Hence, the amino acids present in the algal sample were extracted and estimated using an automated amino acids Analyzer. The results have shown the presence of the following amino acids; Leu, Lys, Ile, Phe, Val, His, Arg, Met, Trp, Thr, Pro, Tyr, Gly, Glu, Asp, Cys, Ser, Ala. The essential amino acids (Leu, Lys, Ile, Phe, Val, His, Arg, Met, Trp, Thr) profile of the alga as compared with conventional protein sources and the WHO/FAO reference pattern of essential amino acids (g per 100 protein), reveals that the levels of the essential amino acids in the alga were either similar to or greater than the levels of the same amino acids in the reference foods and WHO/FAO reference pattern. Thus, results of the present study shows that S.porticalis is a potential source of single cell protein, and may be of use to the food industry as a source of ingredients with high nutritional value. S. porticalis can provide a dietary alternative due to its nutritional value and its commercial value can be enhanced by improving the quality and expanding the range of freshwater macroalgae based products.

44 Practical Application of Ideal Protein Concept after 25 Years.

Perhaps the greatest advance in establishing amino acid requirements for domestic animals, in the past 25 years, has been the implementation of the ideal protein concept (Fuller et al., 1989; Chung and Baker, 1992). This concept has been widely applied in pigs, poultry and dairy cattle nutrition. Calculations account for differences in specific amino acid patterns that are required for various physiological processes (e.g. maintenance, growth, pregnancy, lactation). In pigs, the requirement for each amino acid is expressed as a ratio to the lysine, the first limiting amino acid in typical pig diets. This pattern of essential amino acids is referred to as ‘ideal protein’ as it would precisely meet the physiologic needs of the animal. Importantly, the ideal amino acid pattern required for maintenance (M) differs from that for growth (G). The best illustration of how amino acids patterns vary with changing proportions of M and G is with pregnancy, where the ideal pattern for early pregnancy (low G, tissue deposition) differs from that in late pregnancy (increasing proportion of tissue growth beyond M; mammary, fetal growth, blood volume) (Kim et al., 2009; NRC Swine, 2012). The ideal protein method provides the basis for being dynamic with relative differences in G: M, and in systematically estimating requirements for all amino acids, without empirically proving the requirement for each amino acid. Animal Scientists take for granted this major advance. In contrast, this is one of the most urgent gaps identified for late pregnant and lactating human mothers and pre-maturely weaned children (Odle et al., 2016). Landmark changes in practical amino acid nutrition were set in place by academic leaders (D. Baker, M. Fuller), but integration into practice was driven primarily by Industry leaders. (J. Usry, M. Johnston, D. Boyd, G. Allee). The landscape of practical amino acid nutrition completely changed by (1) defining the lysine requirement curve and (2) relating the most limiting amino acids to lysine. This moved practicing nutritionists away from defining the requirement for each amino acid individually; each under differing conditions. Usry and co-workers proved the academic and financial importance of empirical calibration, and the extent to which certain amino acids change (or do not change) with stage of growth. The ideal protein concept solidified the move from protein formulation and provided a sensible guide as to other essential amino acid needs for pigs with genetically different rates of protein deposition and response to dietary lysine.

Quality assessment of soy sauce using underivatized amino acids by capillary electrophoresis

ABSTRACTFermented soy sauce was identified by determining underivatized amino acids through the proposed capillary electrophoresis-ultraviolet method coupled with sweeping technology for the first time, based on the coordination interaction between amino acids and Cu2+. The essential amino acids pattern was used to the evaluate quality of soy sauce of different grades, the results showed that the quality of special grade soy sauce was higher than that of others. The sample S13 had the highest quality according to the analysis of the 12 kinds of soy sauce by principal component analysis. According to the method of Taste Activity Value, glutamic acids, lysine, alanine, and aspartic acid were considered to be the main taste amino acids in soy sauce.

Establishing the optimum dietary essential amino acid pattern for silvery-black porgy (Sparidentex hasta) juveniles by deletion method

A 6-week feeding trial was conducted to estimate the optimum dietary essential amino acid (EAA) pattern for silvery-black porgy juvenile based on the AA deletion method. Eleven isonitrogenous and isoenergetic diets were formulated containing 60% of fish meal nitrogen and 40% of crystalline AA nitrogen. In the control diet, the EAA profile was made similar to fish meal protein. Ten other diets were formulated similar to the control diet but replacing 40% of each EAA by a mixture of non-essential amino acids. Triplicate groups of fish (initial body weight of 4.7 g) were handfed with the experimental diets, three times a day, to visual satiation, for 42 days. At the end of the trial, final body weight of all EAA-deficient groups was lower than that of control group, ranging from 6.3% of reduction with arginine-deficient diet to 39.4% of reduction with lysine-deficient diet, relatively to the control group. Based on the relationship between nitrogen retention and EAA intake of the control and EAA-deficient diets, the optimal dietary EAA profile for silvery-black porgy juveniles was estimated to be (g 16/g N): arginine 5.3, lysine 6.0, threonine 5.2, histidine 2.5, isoleucine 4.6, leucine 5.4, methionine + cysteine 4.0 (in a diet containing 0.6 cysteine), phenylalanine + tyrosine 5.6 (in a diet containing 1.9 tyrosine), tryptophan 1.0 and valine 4.6.

Effects of varying protein and lipid levels and protein-to-energy ratios on growth, feed utilization and body composition in juvenileNibea diacanthus

A two-factor experiment was designed to determine the suitable dietary protein and lipid levels for juvenile Nibea diacanthus. Nine extruded pellet diets were formulated to contain three levels of protein (420, 470 and 520 g kg−1) and three levels of lipid (70, 110 and 150 g kg−1). Each diet was randomly fed to triplicate groups of 25 juvenile N. diacanthus (initial weight 12.12 ± 0.23 g) for 8 weeks in net cages. The results showed that weight gain rate (WGR), specific growth rate, final body weight and energy retention were significantly influenced by the dietary protein and lipid levels-. The highest WGR (982.5g kg−1.) of N. diacanthus was found in the group with dietary protein and lipid of 520 and 150 g kg−1. Feed intake and feed efficiency were significantly impacted by the dietary protein levels. An interactive effect between dietary protein and lipid on the protein retention and protein efficiency ratio was observed. There were no significant differences in condition factor and survival among all treatments. Hepatosomatic index and viscerasomatic index of N. diacanthus were positively related with dietary lipid levels, but negatively with dietary protein levels. Crude protein, crude lipid, ash, moisture and energy contents of the whole body, muscle and liver were influenced by dietary protein and lipid levels. Moreover, total essential amino acid pattern of the muscle was correlated to those of dietary protein. Total protein concentration in the serum was affected by dietary protein and lipid levels. Meanwhile, both serum cholesterol and triglyceride concentrations increased with increasing dietary lipid levels. These results demonstrate that the diet containing 470 g kg−1 protein and 110 g kg−1 lipid is optimal for juvenile N. diacanthus and analysis of WGR by quadratic regression indicated that the estimated optimal protein-to-energy ratio for juvenile N. diacanthus was 24.53 mg protein kJ−1.

Improving the nutritive characteristics of corn flakes enriched with functional components

This paper investigates the effects of simultaneous addition of sunflower (3, 6 or 9 g/100 g of sample) and dry residue of wild oregano (0.5 or 1 g/100 g of sample) on the essential amino acids pattern and antioxidant potential of flake products. The accepted experimental design plan was 3?4. Data point that Score and PDCAAS values in flake products increase with increasing share of sunflower. Maximum value of phenolic compounds and antioxidant activity were experienced of TPC 2.84 mg/g, DPPH 0.75 mg/ml, FRAP 1.57 mg/g with the product having maximum shares of sunflower and dry residue of wild oregano. Tukey?s HSD test showed statistically significant differences between most of the mean values of amino acids content and antioxidant activity in the observed corn flakes. The response surface method has been applied for evaluation of amino acid content and antioxidative potential of corn flakes. Sunflower in flake products positively contributed to the protein nutritive value and dry residues of wild oregano elevated antioxidant potential of flake products and also contributed to the food waste valorisation in the food industry. Corn flakes are new products with improved essential amino acid pattern, antioxidant activity and functional properties due to added dry residue of wild oregano and sunflower.

Nutritive value of flakes products with sunflower

This paper investigates the influence of sunflower addition (3, 6 or 9 g/100 g of sample) on the essential amino acids pattern of flakes products. The nutritive value of proteins in flakes products is expressed by the amino acid score (AAS) and the protein digestibility-corrected amino acid score (PDCAAS). The results obtained indicate that the AAS and PDCAAS values in flakes products increased with an increase in the sunflower share. Sunflower in flakes products positively contributed to the nutritive value of proteins. Flakes products with 9 g/100 g of sunflower are particularly suitable for adults, an AAS of 0.60±0.06 and a PDCAAS of 51.3±0.3.

A simple estimation of ideal profile of essential amino acids and metabolizable energy for growing Japanese quail.

An experiment was conducted to determine apparent metabolizable energy (AME) and amino acid requirements of growing Japanese quail based on ideal protein concept using artificial neural network and desirability function (D-ANN). Seven-day-old quail chicks were assigned to nine experimental diets based on central composite design (CCD) containing five levels of AME (2809-3091kcal/kg) and CP (19-24.8% of diet). The ratio of lysine (Lys) to CP was set at 0.053 among all treatments, and remaining essential amino acids (EAA) were adjusted to Lys. The experimental data of CCD were fitted to D-ANN model to compute the optimal values for independent variables. The optimal values of inputs including AME, CP, digestible Lys (dLys), methionine (dMet), total sulphur amino acids (dTSAA), threonine (dThr), tryptophan (dTrp), isoleucine (dIle), valine (dVal) and arginine (dArg) for maximizing gain and minimizing feed conversion ratio were estimated at 2865kcal/kg, 25, 1.32, 0.55, 0.88, 0.84, 0.20, 0.75, 1.04 and 1.45% of diet, respectively, with D (desirability function)=0.94. The corresponding optimal amounts of amino acids based on total amino acids were 1.42, 0.59, 0.95, 0.90, 0.22, 0.81, 1.12 and 1.56% of diet respectively. The ideal pattern of essential amino acids to Lys was as follows: dMet: dLys=0.42, dTSAA: dLys=0.67, dThr: dLys=0.64, dTrp: dLys=0.15, dIle: dLys=0.57, dVal: dLys=0.79 and dArg: dLys=1.09. The results of this study showed that amino acid requirements of modern quails might be higher than those reported by NRC.

Effects of dietary protein levels on growth, feed utilization, body composition and ammonia–nitrogen excretion in juvenile Nibea diacanthus

Juvenile Nibea diacanthus were fed various dietary protein levels, and their growth performance, feed utilization, carcass proximate composition and 24-h postprandial ammonia–nitrogen excretion were investigated. Five isoenergetic and isolipidic experimental diets, containing various protein levels ranging from 36 to 52 % by a 4 % increment, were formulated. Each diet was randomly fed to triplicate groups of 25 juvenile N. diacanthus (initial weight 62.85 ± 0.32 g) for 8 weeks. Highest weight gain, specific growth rate, feed efficiency, protein efficiency ratio and protein retention were obtained at 48 % dietary protein levels (P < 0.05). As dietary protein levels increased, feed intake, hepatosomatic index and viscerosomatic index declined significantly. Similarly, the ammonia–nitrogen excretion rate was largely inversely correlated with dietary protein levels, with the lowest value appearing in the 48 % group (P < 0.05). High-protein diets resulted in higher whole-body and muscle protein contents and produced a significant effect on muscle amino acid profile. Also, total essential amino acid pattern of the muscle was significantly correlated to those of dietary proteins. Analysis of specific growth rate and weight gain by broken-line regression indicated that the estimated optimal dietary levels of protein for juvenile N. diacanthus were 48.66–48.94 %.

English

This study evaluated the nutritional qualities of a protein concentrate and an isolate produced from cashew nut. The nutritional qualities were evaluated by determining amino-acid composition, in vitro digestibility and anti-nutritional factors (tannins, trypsin inhibitor activity-TIA and phytic acid content) in the protein concentrate and isolate using standard analytical methods. The amino-acid with the highest concentration in defatted cashew nut powder (DCNP), cashew nut protein concentrates (CNPC), and cashew nut protein isolate (CNPI) was glutamic acid, which was found to be 22.5, 21.38, and 21.81 g/100 g, respectively. This was followed by leucine, aspartic acid and arginine, in that order. The amino-acid with the lowest concentration in DCNP, CNPC, and CNPI was cysteine. The sulphur-containing amino-acids and some other essential amino-acids (lysine, tryptophan, leucine, isoleucine, and tyrosine) in CNPI were not significantly different (p>0.05) from that of DCNP, but were significantly different from that of CNPC (p<0.05). CNPC and CNPI were rich in essential amino-acids, and based on the FAO/WHO recommended essential amino-acids pattern requirements for an infant, the limiting amino-acid in CNPC, and CNPI was lysine with chemical scores of 0.68, and 0.63 respectively. However, the anti-nutritional factors (tannins, TIA, and phytic acid contents) of CNPI were found to be lower than those in DCNP and CNPC, while those of CNPI and CNPC were within the range found in the commercial peanut and soy protein concentrates and isolates. The highest in vitro digestibility was observed in CNPI (95.30%), while CNPC (87.83%) had a higher value than DCNP (79.93%). The nutritional qualities of the protein concentrate and isolate from cashew nut were found to be comparable to those reported for commercial peanut and soy protein concentrates and isolates. Therefore, the cashew nut products could be suitable as additional source of protein ingredients in food formulations. Key words: Cashew, protein, nutrition, isolate, concentrate.

Fatty acid, amino acid, mineral and antioxidant contents of acha (Digitaria exilis) grown on the Jos Plateau, Nigeria.

Digitaria exilis (Kippist) Stapf (also known as acha, hungry rice) has been cultivated for millennia in the dry savannahs of West Africa, but much remains to be learned about its nutritional properties. Acha was collected in four villages in Northern Nigeria and analyzed for fatty acids, minerals, amino acids and antioxidant content. Fatty acids accounted for 1.91% of the dry weight, with 47.4% linoleic acid and 30.5% oleic acid. The content of the essential minerals, copper, magnesium, molybdenum, zinc and calcium averaged 4.88, 1060, 0.23, 23.0 and 172 μg/g, respectively. The protein content was 6.53% and the essential amino acid pattern, except for lysine, compared favorably to a World Health Organization (WHO) reference protein. The total polyphenolic content of methanolic extracts of acha matched that of common cereals (for example, maize, rice, wheat) and the extracts contained substantial amounts of free-radical scavenging substances. Thus, acha is a source of many nutrients critical to human health.

Evaluation of acute toxicity potential of water hyacinth leaves

Although higher protein yield per hectare of water hyacinth than that of soy, high protein content of its leaves and good essential amino acid pattern have been proven, its dietary toxicity for human or animal consumption has not yet been evaluated. Therefore, the acute toxicity of water hyacinth leaves has been evaluated by an animal feeding test. The concentrations of common toxic metals including cadmium, lead, platinum, palladium, tin, mercury, barium, silver, stibium and aluminum in the water hyacinth leaf powder (WHLP) used for the animal feeding test were within their maximum limits in food additives as reported by the World Health Organization. The median lethal dose (LD50) of WHLP was more than 16 g kg(-1) body weight. In the study, after feeding for 7 and 28 days, the body weight of all the mice increased. The results of hematological analysis, clinical biochemical analysis, histopathological evaluation, general dissection or investigations of internal organs, appearance and behavior observations did not indicate any adverse effects from the diet containing WHLP. It is therefore concluded that water hyacinth leaves are not acutely toxic.

Furthering an understanding of West African plant foods

PurposeThe main purpose of this paper is to determine the content of amino acids, fatty acids and minerals in seven indigenous leafy vegetables (ILVs) in Ghana.Design/methodology/approachLeaves from plants growing near Kumasi were milled to a fine powder, dried to constant weight in a vacuum desiccator, and analyzed for their content of the afore‐mentioned nutrients. The plants were: Hibiscus sabdarifa, Hibiscus cannabinus, Amaranthus cruentus, Corchorus oliforius, Solanum macrocarpon, Xanthomosa sagittifolium and Vigna unguiculatus.FindingsAll seven ILVs contained a large amount of protein (15.5‐22.8 percent), which compared favorably to the essential amino acid pattern of a WHO standard. They all contained nutritionally useful amounts of α‐linolenic acid and had an omega‐6/omega‐3 ratio of 0.1‐0.9. The seven ILVs contained quantities of calcium, copper, iron, magnesium, manganese, molybdenum and zinc that could contribute significantly to satisfying an individual's need for these elements.Research limitations/implicationsThe presence of relatively large amounts of various nutritionally essential macro‐ and micronutrients in these seven ILVs does not necessarily mean these nutrients are bioavailable. Future research is required to determine the amounts of anti‐nutrients (e.g. protease inhibitors, chelators) in these vegetables, and the extent to which their protein, lipid and mineral constituents are digested and/or absorbed.Originality/valueSince malnutrition (e.g. iron‐deficiency anemia, rickets, zinc deficiency, protein‐calorie malnutrition) is common in sub‐Saharan Africa, the information which is provided should increase awareness among agricultural and public health officials of the nutritional value of seven underappreciated and underutilized ILVs that are indigenous to Ghana and many other parts of Africa.