The nutritive value of new high-lysine barley mutants

Four new high-lysine barley mutants, the mother variety ‘Sultan’, and the cultivar ‘Lysimax’ with the high-lysine gene lys3a were grown in a field trial in 1992 at Riso, Denmark. Yield and 1000 kernel weights were measured. The material was analyzed for protein, fat, starch, soluble non-starch polysaccharides, insoluble non-starch polysaccharides, lignin, β-glucans, sugars, energy and amino acids. The nutritive value was evaluated in balance experiments with rats. The mutants yielded less than the mother cultivar ‘Sultan’ in the range 80–96%. Thousand kernel weights were also lower than for the mother cultivar. The protein concentration was higher in the mutants, with the highest value of 14·2% vs 12·9 in ‘Sultan’. The fat content was usually higher in the mutants, with the highest value of 5·3% vs 3·9% for ‘Sultan’. The starch content varied considerably, from 51·2%–60·3% for the mutants, while ‘Sultan’ contained 58·2%. The level of dietary fibre was usually higher in the mutants compared to the level in ‘Sultan’ (19·7%). β-glucan and sugar contents varied among the mutants, with values higher and lower than in ‘Sultan’. ‘Sultan’ contained 3·31 g lysine/ 16 g N vs 4·73 g N in one of the mutants. The higher lysine content resulted in an 11·6% unit increase (P<0·05) in biological value (77·6% for ‘Sultan’ vs 88·2% for this mutant). The protein digestibility was usually higher (P<0·05) in ‘Sultan’ (87·1%). Energy digestibility was slightly lower (P<0·05) in the mutants compared to the value for ‘Sultan’ (84.1%).     

Relationship of phenotypic variation in sorghum to nutritive value of crop residues

Improvements in dry matter digestibility of crop residues contribute to greater productivity of livestock consuming dual-purpose sorghums (Sorghum bicolor L. Moench). Delayed leaf senescence (stay-green), brown-midrib (bmr), leaf disease resistance, and high yield are among sorghum phenotypic traits that could enhance nutritive value of crop residues. The objective was to evaluate nutritive value and hydrocyanic acid potential (HCN-p) of leaf or stem components of crop residues of sorghum lines and hybrids representing differences in phenotypic traits. Four replications of eight or more lines and hybrids made up a randomized complete block design during 2 years in central Texas. Dry matter yield, dry weight loss after extraction in water and incubation in rumen, and fiber concentrations of leaves and stems were measured after grain harvest under field conditions. In addition, HCN-p of axillary branches and mature leaves was quantified. Sample weight loss in water extractions without incubation in rumen was negatively correlated with fiber concentrations, which were measured as the sample weights remaining after extraction in neutral (NDF) and acidic (ADF) detergent solutions. Greater concentrations of water-extractable dry matter and lower concentrations of NDF and ADF were observed for stay-green than for bmr or lines that senesced under drought. Yet, the sum of water-extractable dry matter plus ensuing weight loss during 7 days in rumen, expressed as yield ha⁻¹ of leaf and stem digestible dry matter, was not consistently greater for stay-green than drought-susceptible lines. In addition, the yield of the sum of water-extractable and 7-day rumen losses of stay-green lines was comparable to or less than the bmr line. Under conditions in which leaf senescence varied little, analyses of nutritive value indicated water-extractable dry matter was enhanced and fiber concentrations were reduced in crop residues of stay-green compared to senescent lines.     

Physical and nutritional qualities of extruded weaning foods containing sorghum,pearl millet,or finger millet blended with mung beans and nonfat dried milk

Sorghum, pearl millet, and finger millet flours (60% of each) were blended with toasted mung bean flour (30%) and nonfat dry milk (10%) and extruded (Brabender single screw) to make precooked, ready-to-eat, weaning foods. The extruded foods had high cold paste viscosity, but their cooked paste viscosity was lower than that of the respective blends. Chemical scores of the extruded foods were 78 for sorghum, 80 for pearl millet, and 96 for finger millet. Protein digstibility corrected amino acid scores (PD-CAS) were similar for pearl millet (68%) and finger millet (69%); PD-CAS for sorghum was 57%. Total dietary fiber content of the foods ranged from 7.6 to 10.1%, with the soluble dietary fiber content of the foods being about 10% higher than that of the corresponding blends. Extrusion enhanced the in vitro protein digestibility of foods, but no marked difference occurred in the in vitro carbohydrate digestibility among the unprocessed blends and the extruded foods. The net protein ratio, protein efficiency ratio, and biological values were higher for the finger millet food than for the pearl millet food, probably because of the higher lysine content of the finger millet protein.Contribution No. 95-253-J of the Kansas Agricultural Experiment Station.     

The composition and nutritive value of protein concentrates from potato haulms

Summary Protein concentrates were prepared from potato haulms by standard, methods. There were distinct differences between potato varieties in chemical composition and nutritive value of their concentrates. The amino acid composition of proteins was similar and deficiency of sulphur amino acids was observed. The biological value of proteins of the best preparations was nearly as good as that of soya bean meal protein but their digestibility was lower.

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Zusammenfassung Aus Kartoffelkraut von 8 Kartoffelsorten wurden Eiweisskonzentrate hergestellt. Eine Parzelle der Sorte Uran wurde mit Stickstoff gedüngt (180 kg N/ha). Frisch geschnittenes Kartoffelkraut wurde gemahlen, der Saft ausgepresst, daraufhin das Safteiweiss thermisch koaguliert und nach Filtration getrocknet. Die H?lfte des feuchten Eiweisskoagulats der Sorte Merkury wurde vor dem Trocknen mit Wasser gespült, dat mit HCl auf pH 4,0 anges?uert wurde. Bei Anwendung dieser Methode konnte bis zu 155 kg Eiweiss pro Hektar erzielt werden. Die Konzentrate enthielten ungef?hr 45% Eiweiss, 12 % Fett und 18 % Asche in der Trockenmasse (Tabelle 1). Der Karotingehalt schwankte zwischen 85 mg und 335 mg und der des Solanins zwischen Spuren und 1015 mg pro Kilogramm des Konzentrates. Die Zusammensetzung der Aminos?uren aller Eiweisskonzentrate war ?hnlich (Tabelle 2). Sie enthielten verh?ltnism?ssig viel Lysin, aber wenig Schwefelaminos?uren. Dennoch enthielten sie mehr Methionin als das Sojabohnenprotein, das als Standard benutzt wurde. Es wurden deutliche Unterschiede im N?hrwert der mit Hilfe der Bilanzmethode von Thomas-Mitchell an Ratten bestimmten Proteine festgestellt (Tabelle 3). Der biologische Eiweisswert betrug 39 bis 62 und war für die besten Konzentrate fast so hoch wie für das Sojaprotein, die Verdaulichkeit war jedoch geringer. Wahrscheinlich war dies auf den hohen Aschegehalt in den Konzentraten zurückzuführen. Die Stickstoffdüngung hatte eine Steigerung der vom Hektar erzielten Eiweissmenge zur Folge. Sie hatte keinen Einfluss auf die Zusammensetzung des Eiweisses, aber erh?hte seine Verdaulichkeit. Dies konnte das Resultat eines h?heren Gehaltes an leicht l?slichen, Protein nicht enthaltenden Substanzen im Konzentrat der gedüngten Pflanzen sein. Das Spülen mit Wasser erh?hte den Gehalt aller Aminos?uren im Konzentrat und den biologischen Wert des Eiweisses, vielleicht als Folge des Auswaschens von Stickstoff aus dem Konzentrat, der nicht an Eiweiss gebunden war. Die erzielten Ergebnisse zeigen, da? das Kartoffelkraut einen guten Rohstoff für die Produktion von Eiweisskonzentraten bilden kann. Diese Konzentrate enthalten eine zufriedenstellende Menge an Eiweiss, Karotin und einzelnen Aminos?uren mit Ausnahme der Schwefelaminos?uren. Der biologische Wert des Eiweisses der besten Konzentrate ist nur et was schlechter als der des Sojabohnenproteins.

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Résumé On a réussi à produire des concentrés protéiques à partir du feuillage de 8 variétés, une partie de la culture d’Uran ayant re?u une fumure azotée (180kg N/ha). Les fanes fra?chement récoltées ont été broyées et pressées. Les protéines contenues dans le jus ont été coagulées par la chaleur et séchées après filtration. La moitié du coagulum protéique humide de la variété Merkury a été rincé avec une eau acidifiée par HCl (pH 4,0) avant séchage. Grace à cette méthode 155 kg de protéines ont été obtenus par hectare. Par rapport à la matière sèche, les concentrés contenaient environ 45% de protéines, 12% de lipides extractibles par l’éther et 18% de cendres. La teneur en carotène variait de 85 à 335 mg/kg et celle de la solanine de quelques traces à 1015 mg/kg de concentré (tableau 1). Les protéines avaient une composition en amino acides semblable (tableau 2). Elles étaient relativement riches en lysine mais pauvre en amino acides soufrés. Cependant elles contenaient plus de méthionine que la protéine du soja utilisée comme témoin. La valeur nutritive des protéines a été déterminée sur des rats par la méthode de bilan de Thomas-Mitchell. Des différences ont été constatées (tableau 3). La valeur biologique variait de 39 à 62 et pour les meilleurs concentrés était presque aussi haute que pour la protéine du soja (VB=66). La digestibilité des protéines de concentrés était relativement basse. Cela était probablement d? à leur teneur élevé en cendres. La fumure azotée a augmenté la quantité de protéines produites à l’ha. Elle n’a pas eu d’effet sur la composition en acides aminés mais a augmenté la digestibilité des protéines. Le lavage augmenterla teneur en amino acides et la valeur biologique de la protéine, peut être parce que le rin?age élimine du coagulum l’azote non protéique. Les résultats obtenus indiquent que les fanes de pommes de terre peuvent être une bonne matière première pour la production de concentrés protéiques. Ces concentrés contiennent des quantités satisfaisantes de protéines, carotène et acides a minés à l’exception des acides aminés soufrés. La valeur biologique de la protéine des meilleurs concentrés est seulement légèrement inférieure à celle de la protéine soja.

     

The nutritive value of Prangos ferulacea

This study was conducted to determine the chemical composition and nutritive value of Prangos ferulacea, a plant found in the Mediterranean and Middle‐east regions, where it is used as animal fodder. Samples of mature plants were collected from S.E. Turkey. Metabolizable energy (ME) values were estimated from in vitro gas production measurements and from chemical composition. ME concentrations of the whole plant, leaves and stems were estimated to be 12·2, 11·9 and 12·7 MJ kg^?1 dry matter (DM) respectively, which compares favourably with high‐quality forages commonly used in ruminant feeding. The DM degradability of the whole plant, leaves and stems increased up until 48 h of in situ incubation, 866, 915 and 784 g kg^?1 DM respectively, but changed little between 48 and 72 h. In vitro DM and organic matter digestibility of the whole plant, leaves and stems were 0·769 and 0·806, 0·773 and 0·790, and 0·740 and 0·840 respectively. The results show that P. ferulacea may be regarded as a high‐energy forage, but further research is needed on its intake characteristics and the levels of animal performance that can be achieved from its inclusion in the diet.     

Harnessing sorghum and millet biotechnology for food and health

This review highlights recombinant DNA technology as a powerful tool to enhance the gene pools of sorghum and pearl millet crops regarded as jewels of Africa. Although important advances in the improvement of these species have been made by classical breeding and modern marker assisted selection, genetic manipulation and in vitro culture allows the gene pool to be broadened beyond that normally available for improvement by allowing the transfer of genes which control well-defined traits between species. The current state of sorghum and millet transformation technology is summarised and applications in the improvement of nutritional quality and the resistance to pathogens and pests for crops grown in Africa and Asia is discussed. Regulatory aspects including gene flow and future prospects are also discussed.     

Influence of processing conditions on the nutritive value of Ogi-baba,a Nigerian fermented sorghum gruel

The effect of germination, cowpea fortification and fermentation on thechemical and amino acid composition of ogi-baba, a Nigerian fermented sorghum gruelwas investigated. The lowest protein value of 1.4% was obtained in the traditionally preparedsample, while samples prepared from germinated, fortified sorghum had 13%. The ash ranged from 0.9% to above 2%, while the fat was in the range of 1.2% to2.8%. Generally, fortification, in addition to germination, improved the chemicalcomposition of ogi-baba relative to the control sample. There was improvement in the amino acidprofile of all the ogi-baba samples compared to the unprocessed sorghum grains.Lysine, a limiting amino acid in sorghum, increased more than 50% in ogi-baba. However, samples prepared using germinated sorghum without the addition of cowpeas hada lower lysine content.     

Harnessing sorghum and millet biotechnology for food and health

This review highlights recombinant DNA technology as a powerful tool to enhance the gene pools of sorghum and pearl millet crops regarded as jewels of Africa. Although important advances in the improvement of these species have been made by classical breeding and modern marker assisted selection, genetic manipulation and in vitro culture allows the gene pool to be broadened beyond that normally available for improvement by allowing the transfer of genes which control well-defined traits between species. The current state of sorghum and millet transformation technology is summarised and applications in the improvement of nutritional quality and the resistance to pathogens and pests for crops grown in Africa and Asia is discussed. Regulatory aspects including gene flow and future prospects are also discussed.     

Response of pearl millet to grain sorghum environments

Increasing awareness of drought tolerance in pearl millet [Pennisetum americanum (L.) Leeke.] has stimulated research into pearl millet as a potential U.S. crop. Objectives of this study were to compare yield and yield components of pearl millet and grain sorghum [Sorghum bicolor (L.) Moench] and evaluate pearl millet response to a range of grain sorghum environments.Yield and yield component comparisons were made using 24 millet hybrids and six grain sorghum hybrids at seven Kansas locations, from 1980 to 1982. To compare pearl millet production in grain sorghum environments, millet hybrid mean yields were regressed on sorghum location means. A desirable millet hybrid would have a high yield and a regression coefficient not significantly different from 1.0.Average grain sorghum yields were greater than millet yields in all three years. Millet hybrid yields ranged from 350 to 5400 kg ha⁻¹. Over all locations and years, millet yield averaged 63% of sorghum yield.In unfavorable environments, pearl millet yield and response to changing environments were not significantly different from those of grain sorghum. As environmental conditions improved, sorghum significantly yielded more than millet. Lower millet yields could be attributed to significantly smaller seed size and head sterility. The small seed also reduced plant establishment; however millet's tillering ability compensated for reduced population.     

Trypsin inhibitors and nutritive value in cereals

Chemical assays demonstrated that rye and barley cultivars contained relatively high levels of trypsin inhibitor activity as compared to oat and wheat cultivars, and there was a low degree of stability to prolonged wet heat treatment. In feeding trials with broiler chicks, incorporation of 67% raw barley or 50% raw rye in the rations enhanced feed intake and weight gains, and the marginal increases in pancreas weight were not reversed by feeding autoclaved cereals. Raw rye cultivars fed at the 75% level in mouse diets reduced weight gains, feed efficiency, protein digestibility, protein efficiency ratio and biological value. Autoclaving to inactivate trypsin inhibitors, or ether extraction to remove the resorcinols, failed to improve the nutritive value of rye diets for mice. It appeared that the protease inhibitors in the four cereals were relatively weak inhibitors of trypsin in the digestive system despite stability to dry heat and acid pH.     

The nutritive value of amaranth grain (Amaranthus caudatus)

Digestibility of dietary fibre (DF) and energy of three pale-seeded and one darkseeded variety ofAmaranthus caudatus were studied in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 8% of DF and the black seeds about twice as much. The soluble DF fraction made up 33–44% of the total DF (TDF) fraction in the pale-seeded varieties, but only 18% in the black seeds. The monomer sugar composition of the DF was very similar in all products. However, the black seeds were very high in lignin, and DF of the black-seeded products were more resistant to digestion than that of the pale-coloured products. In the pale amaranth products digestible energy (DE) varied between 86 and 91%. In the dark-seeded products DE was lower, and there was a significant negative correlation (r=–0.92) between DE and TDF. Processing of pale seeds had only minor effects on TDF and DE, but increased the proportion of soluble DF and the digestibility of DF in one variety. The food intake tended to be lower in rats fed raw pale seeds compared with those consuming processed products, indicating the presence of heat-labile factors reducing palatability.In conclusion, the pale seeds had a lower content of DF than most cereal grains and the DF was more easily digested. As a source of energy, amaranth grains seem to be comparable to other cereals.     

Nutritive value of malted millet flours

The changes in proximate composition, phytate phosphorus, thiamine and ascorbic acid content of finger millet, pearl millet and foxtail millet during progressive germination were studied. Germination resulted in a slight decrease in total protein and minerals, a marked fall in phytate-phosphorus and a significant increase in the ascorbic acid content of the millets. An increase in lysine and tryptophan but no appreciable changes in threonine and sulfur amino acid content of the millets were observed as a result of germination. However, the protein efficiency ratio values of ungerminated control seeds, 48 h germinated green malt and kilned malt were not significantly different.     

The nutritive value of some selected Tanzanian plant food sources

The chemical composition of different varieties of field beans (Vicia faba L.), cowpeas (Vigna unguiculata), groundnuts (Voandzeia subterranea), and sorghum (Sorghum vulgare) were determined. Nutrients analysed in these materials included amino acids, starch, sugar, fibre, minerals and antinutritional factors. All the materials were further tested in balance trials with rats; true protein digestibility (TD), biological value (BV), net protein utilization (NPU) and digestible energy (DE) were evaluated. Based on the chemical analyses as well as on the biological data, the nutritive value of plant materials between species as well as between varieties within species differed considerably. Therefore, more quality evaluation studies along with plant breeding programmes are needed to select the most promising varieties from the nutritional point of view.     

Production and evaluation of weaning foods based on sorghum and legumes

Five weaning formulations (F1-F5) based on sorghum, groundnuts, sesame seeds, chickpeas, and skim milk powder were processed by a twin-roller drum dryer and evaluated for composition, functional properties (bulk density, water absorption capacity, and apparent viscosity), in vitro indices (protein digestibility and available lysine), protein quality (PER, NPR, and NPU) and effects of feeding on rat livers. Composition and properties of the five formulations were compared to those of Cerelac. The results indicated that F3 (60% sorghum, 20% chickpeas, 5% sesame, 8.5% skim milk powder, 5% sugar, and 1.5% vitamins and minerals) and F2 (55% sorghum, 15% chickpeas, 5% groundnuts, 10% sesame, 8.5% skim milk powder, 5% sugar, and 1.5% vitamins and minerals) formulations had compositions and properties comparable to those of Cerelac and hence have a good potential for use as weaning foods.     

The nutritive value of amaranth grain (Amaranthus caudatus)

The nutritional value of three pale seeded and one dark seeded variety ofAmaranthus caudatus was studied by chemical analyses and in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 14% protein, 10% fat, 2.5% ash, 64% starch and 8% of dietary fibre. The black seeds had a much higher content of fibre (16%). The concentration of essential amino acids were high. Lysine ranged from 5.2–6.0 g/16 g N in the grains, and the limiting amino acids were leucine followed by valine or threonine. The grains contained small amounts of tannin (0.3%) and heat-labile protease inhibitor activity, at levels typical of common cereal grains. Digestibility of protein in the pale seeds was high (87%) and quite unaffected by processing. Protein digestibility of the black seeds was lower, and the digestibility was further reduced by toasting. The biological value of the protein was similar in all products, and very high. The content of minerals varied among varieties and was also affected by processing. Phytate: zinc molar ratios were high in most products, and rats fed the amaranth samples with the lowest zinc contents were in negative zinc balance. In general, femur zinc concentrations were rather low. However, amaranth is an unconventional crop which deserves further attention.     

Development,nutritive content and shelf life of home processed supplementary foods

Four low cost supplements containing whole wheat, pearl millet, bengal gram, green gram grain and amaranth leaves employing roasting and malting methods were developed. Nutritional evaluation showed that chemical composition of developed supplements was within the range prescribed for processed supplements and could meet satisfactorily one third requirements of protein, energy, iron and calcium for young children. Developed supplements were stored in three packings, polythene bags, tins with lids, glass bottle with lids (each 1 kg capacity, under ambient temperature (24–32°C) and RH (70–80%) for a period of 30 days and analysed for moisture, peroxide value, fat acidity and alcoholic acidity. Stored samples were also evaluated organoleptically. The values of moisture, peroxide value, fat acidity and alcoholic acidity of stored samples were within the range of prescribed specifications for processed supplements. Storage of supplements for 30 days resulted in non-significant changes in organoleptic traits except for taste and aroma of bajra based supplements on 20th and 30th day of storage. In spite of these variations, all the supplements were found to be acceptable till 30th day of storage.     

The influence of milling on the nutritive value of flour from cereal grains. 5. Maize

Different grades of maize flour were produced by dry milling of yellow maize. The chemical composition of wholemeal, three semi-sifted flours and degermed maize was determined, and the nutritional value of the flours were investigated in balance experiments with growing rats. Distinct differences in nutrient and fibre content were found. Amino acid composition was significantly different in the milled fractions, and the content of minerals and phytate in the flours was determined by the extent to which the germ was retained. Phytate: zinc molar ratios ranged from 43 to 2. Weight gain of rats was closely correlated to the concentration of lysine (r=0.99) and tryptophan (r=0.97). Weight gain of rats fed degermed maize was reduced to half of that of rats fed wholemeal. True protein digestibility was high, but protein quality varied widely between the different flour fractions. Energy density of the flours was quite similar. Rats fed wholemeal had the highest intake of zinc and the highest apparent zinc absorption and retention but the lowest femur zinc concentration. Factors present in whole maize may interfere with zinc utilization. The results might indicate an interaction between phytate and fibre. Supplementation of wholemeal with lysine and tryptophan increased the biological value of the protein and the weight gain considerably, but apparent absorption and retention of zinc as well as femur zinc concentration were similar in unsupplemented and supplemented rats. The percentage of zinc absorbed from degermed maize flour was high, but degermed maize has a very low content of minerals and is highly deficient in lysine and tryptophan.     

The influence of milling on the nutritive value of flour from cereal grains. 1. Rye

Rye was milled into flours having extraction rates between 100 and 65%. The nutritive value of the various fractions was studied by chemical analyses and in balance trials with rats. The concentration of essential nutrients decreased when the extraction rate was lowered. The lysine content (g/16 g N) was 4.23 in whole rye, but only 3.76 in the 65% extraction flour, and a corresponding reduction in biological value was found. A reduction of 50% or more was observed for several minerals with zinc and phosphorus being most affected. The apparent zinc absorption and retention expressed in absolute values, were significantly higher from the flours of high extraction than from the more refined flours, in spite of a much higher phytate content in whole rye and lightly milled flours. It could be concluded that milling of rye into highly refined flours not only preclude considerable amounts of nutrients from human consumption, but the remaining flours have a much poorer nutritive value than flour made from whole rye.