Nutritive Value Of Leaf Protein Research Articles

Chemical composition and nutritive value of leaf protein concentrate from leucaena leucocephala

AbstractLeaf protein concentrate (LPC) was prepared from Leucaena leucocephala leaf meal (LLM). The recovery of LPC was 7.6 % and analysis showed that the LPC contained 65.91 % crude protein compared with 29.15 % of the LLM, ash content was 17.56% while levels of essential amino acids‐lysine, histidine, arginine, isoleucine and leucine—were 5.57, 2.34, 5.88, 5.42 and 10.8% on a dry matter basis, respectively. The LPC had higher in‐vivo digestibility than the LLM with values being 63.20 and 48.82%, respectively. The LPC diet supported growth in rats but gave lower nutritive indices than the control diet of soya bean and Guinea corn.

The changes of the yield, composition and nutritive value of leaf protein extracted from vetch and cereal mixtures during three years cultivation

Three mixtures of vetch with cereals (rye, triticale and wheat) were grown during three consecutive seasons 1985/86, 1986/87 and 1987/88 and leaf protein concentrates (LPC) were prepared using the standard method. LPC were analysed for their gross composition and amino acid content. True digestibility (TD) and biological value (BV) of LPC proteins were estimated on rats using the Thomas-Mitchell balance method. There were no statistical differences in green matter and dry matter yield in the course of the whole experiment. However, in the first season (1986) the yield of vetch × rye mixture was apparently higher and that of the other two mixtures was lower than in the next two years. The protein content of LPC in 1986 was lowest, especially in the concentrates obtained from the triticale and wheat mixtures. There were only small differences in amino acid composition of proteins and these differences did not depend on the year of cultivation or species of cereal used. BV of protein extracted from the rye-containing mixtures was always lower than that of other preparations (means of three years: rye 40, triticale 46, wheat 49). Protein extracted in 1987 had the highest BV. It can be concluded that the season of cultivation affects the green and dry matter yield of legume x cereal mixtures though these differences are levelled off during long-term experiments. The LPC quality is affected both by the kind of cereal and year of cultivation.

Yield, composition and nutritive value of leaf protein concentrates from mixed forages of cereals and legumes

Leaf protein concentrates (LPC) were produced from high- and low-legume (high-cereal) mixtures of forage. The forages were obtained by sowing seed mixtures containing either 60% legume and 40% cereal or 60% cereal and 40% legume (air dry matter). The legumes used were vetch and pea, and the cereals were wheat, triticale and barley. Average green- and dry-matter yield was highest for high-legume mixtures containing vetch. Barley-containing mixtures gave higher yields than those containing wheat or triticale. The LPC were analysed for their gross composition and amino-acid content. Biological value and true digestibility of LPC protein were estimated in rats using the Thomas-Mitchell balance method. Protein content of LPC was low (32.3–46.7% dry matter basis). All concentrates were poor in sulphur amino acids and their content of basic amino acids was unexpectedly low. Protein extracted from low-legume forages was higher in biological value than that from high-legume forages, while true digestibility did not differ significantly. It can be concluded that increasing the proportion of legume in mixed (legume-cereal) forages increases the yield of green and dry matter per unit area, but significantly decreases nutritive value of extracted protein.

The effect of toxic substances present in some leaf protein concentrates on their nutritiv value

The composition and nutritive value of leaf protein concentrates (LPC) from various cultivars of potato and tobacco, m and various species of lupin, were investigated with special respect to the content and effect of anti-nutritional substances. Biological value (BV) and true digestibility (TD) of proteins were determined in rats using the Thomas-Mitchell balance method. No distinct differences in amino acid composition of proteins extracted from particular plants were found. The nutritive value of concentrates from potato haulm was not correlated either with their amino acid composition or solanine content. LPC from cv. Nysa contained the highest amount of solanine (1015 mg kg −1), but its protein was of the highest biological value (62). Both BV and TD of protein extracted from the leaves of bitter lupin were significantly lower than these from sweet lupin (BV = 50 and 62, TD = 77 and 81, respectively). Nicotine contained in LPC from tobacco had lethal effects on some of the rats. It was concluded that anti-nutritional and toxic substances present in the green matter of plants can penetrate LPCs and in some cases impair their nutritive value. Thus, in vitro tests cannot provide an adequate basis for the prediction of LPC quality.

Application of in vitro methods to assess the nutritive value of leaf protein concentrates

Application of in vitro methods to assess the nutritive value of leaf protein concentrates

The effects of processing methods and cholesterol addition on the nutritive value of leaf protein concentrates in chicks.

The effects of processing methods and cholesterol addition on the nutritive value of LPCs prepared from alfalfa, Italian ryegrass and ladino clover were studied in chicks. Each LPC fortified with methionine was used as a sole protein source, providing 10% protein in the diet.The washing by ethanol of thermally-treated coagulum obtained from alfalfa was effective in reducing the medicagenic acid content and improving the nutritive value, whereas this treatment had little effect on the nutritive value of Italian ryegrass and ladino clover LPCs.The adjustment of the alfalfa extract to pH 8 by NaOH had little effect on the medicagenic acid content but significantly improved the nutritive value although it was still inferior to the nutritive value of the ethanol-treated LPC.The heated and NaOH-treated alfalfa LPCs high in the medicagenic acid content had a hypocholesterolemic effect. The addition of 1.0% cholesterol was as effective as the ethanol treatment in improving the nutritive value of the heated and NaOH-treated alfalfa LPCs.The nutritive value of alfalfa and Italian ryegrass LPCs coagulated by anaerobic fermen-tation of the extract for 7 days was much lower than that of the thermally-treated LPCs. In the case of the fermented alfalfa LPC, the accumulation of medicagenic acid was observed and the cholesterol addition was not so effective.This work was supported by a grant-in-aid for Co-operative Research No. 59360036 from the Ministry of Education, Science and Culture in Japan.

Nutritive value of leaf protein concentrates for young chicks.

Eight-day old chicks were fed the diets containing leaf protein concentrates (LPCs) with or without supplementation of deficient amino acids as a sole protein source to supply 19-20% crude protein in the diet. The performance of the chicks fed the LPC diets was compared with that fed the methionine supplemented soybean protein control diet. The LPCs used here were obtained from the mixture of alfalfa+barnyard grass (LPC A), from the mixture of oat+annual meadow grass (LPC B) and from ladino clover (LPC C). Chemical analysis showed that the LPC A diet was deficient in arginine and methionine and the LPC C diet in arginine, when compared to the NRC requirements for chicks. Feed intake of the birds fed the LPC A or LPC A+Arg+Met were not significantly different from that of the control diet, while the birds received the LPC B consumed significantly more diet than the control. Feed intake of the birds fed the LPC C or LPC C+Arg were significantly lower than that of the control. Body weight gain and feed efficiency were significantly lower in the LPCs than in the control. Even when the deficient amino acids were supplemented to the LPC diets no significant improvement of both body weight gain and feed efficiency was observed. Nitrogen retention rate was significantly lower in the LPC diets than in the soybean protein control diet even when the LPCs were supplemented with deficient amino acids. Energy metabolizability was extremely low in the LPC diets compared to that of the soybean protein diet. Among the LPCs including those supplemented with deficient amino acids, LPC B (oat+annual meadow grass) showed the highest protein utilization and energy metabolizability. The inferiority of LPCs in protein and energy utilization might lead the low nutritive value of LPCs for poultry.

In vitro methods to assess the nutritive value of leaf protein concentrate.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIn vitro methods to assess the nutritive value of leaf protein concentrateBadri P. MaliwalCite this: J. Agric. Food Chem. 1983, 31, 2, 315–319Publication Date (Print):March 1, 1983Publication History Published online1 May 2002Published inissue 1 March 1983https://doi.org/10.1021/jf00116a033RIGHTS & PERMISSIONSArticle Views161Altmetric-Citations30LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (663 KB) Get e-Alerts Get e-Alerts

Nutritive evaluation of leaf protein concentrates made from different crops in chicks.

The nutritive value of leaf protein concentrates (LPCs) made from different crops was examined in chicks in connection with methionine supplementation. Two feeding experi-ments were made in which LPCs were used as a sole source of dietary protein to provide 18% crude protein. In the first experiment, the supplementation of 0.2% L-methionine improved the nutritive value of both LPCs made from broad bean and ladino clover though there was no difference in the nutritive value between both the LPCs. In the second ex-periment, the nutritive value of five LPCs was compared with that of soybean meal or isolated soybean protein. Without the supplementary methionine, the nutritive value of LPCs made from Italian ryegrass and oats-annual blue grass mixture (3:7 in a dry matter basis) was higher than that of the leguminous LPCs made from broad bean, ladino clover and red clover. This difference was related to the sulfur-containing amino acids content in the LPC. Thus, the supplementation of 0.2% L-methionine was more effective in improving the nutritive value of the leguminous LPCs low in the sulfur-containing amino acids and consequently diminished the nutritive difference among LPCs except the broad bean LPC. However, the nutritive value of LPCs with supplemental methionine was still inferior to that of soybean meal or isolated soybean protein. The nutritive value of the alfalfa LPC was examined in the second experiment, but feeding the alfalfa LPC diet caused the death of all the chicks, regardless of the methionine supplementation.

A Study of the Chemical Composition and Nutritive Value of Leaf Protein Concentrates

Leaf protein concentrates from alfalfa and from clover obtained by solvent-precipitation and by heat-coagulation have been examined for their chemical composition, their nutritive value and their digestibility. The amino acid composition is not affected by the process of precipitation except that solvent precipitation seems to retain more methionine and less leucine than the heat process. Alfalfa and clover have similar amino acid patterns except that alfalfa has more cystine, aspartic acid and serine than clover.The lipids retained with the protein by the heat process contain much more linolenic and less palmitic, stearic, oleic and linoleic acids than those by the solvent process. Acetone retained more linoleic and linolenic acids and less stearic and palmitoleic acids than alcohol. The lipids of clover had more stearic and oleic acids than those of alfalfa. More mineral elements except Na and Fe and more carbohydrates were found in the solvent-precipitated concentrates than in the heat-coagula. Alfalfa protein concentrate was more digestible and had a higher P.E.R. value than clover protein concentrate. Both, however, were inferior to casein. Dispersibility in water was greater for solvent-precipitated than for heat-precipited concentrates.

Studies on nutritive value of left protein from lucerne (Medicago sativa). 3. Supplementation of rat diets based on wheat.

AbstractGrowth responses of weanling female rats for 4 to 8 weeks, and the Protein Efficiency Ratio (PER) for 4 weeks were measured for diets of wheat flour (W) and three mixtures of wheat and lucerne leaf protein (W:LP). Increasing the proportion of leaf protein in, and the protein content of the mixtures led to progressive improvements up to 4 weeks, but there was no significant difference in weight gain after 8 weeks between the supplemented diets.4‐week growth and PER studies using diets of wheat, lucerne leaf protein and mixtures of these two substances in various proportions, but all containing around 10% protein, showed that the diets containing 40–60% of the mixture‐protein derived from lucerne preparations promoted significant responses the best results being given by the W50:LP50 mixture. The content of some of the essential amino acids in these diets, on calculation, showed that in the W50:LP50 mixture the deficiency (in comparison with the F.A.O. Reference Protein) of threonine, valine, isoleucine and lysine in wheat is eliminated. Both wheat and lucerne leaf protein are deficient in methionine; cystine, of which there is an adequate amount in wheat but not in lucerne leaf protein, becomes marginal at a protein ratio of W80:LP20 and is deficient by only 10% in the W50:LP50 mixture. The optimum response obtained from the latter indicates that it contains the best balance of essential amino acids possible with these two substances. The decrease in the efficiency of mixed diets containing more than 50% of the protein from lucerne preparation is possibly due to the progressively increasing deficiency in total S‐containing amino acid content.

Nutritive value of leaf protein concentrates. I.—Effect of addition of cholesterol and amino‐acids

AbstractThe value of leaf protein concentrates as supplements to cereal diets for chicks has been studied using the ‘gross protein value’ technique. Protein concentrates from different crops have been found to vary widely in nutritive value, but have in all cases been inferior to casein. Concentrates from lucerne contained a factor depressing chick growth, the effect of which was counteracted by adding cholesterol to the diets. This factor was not found in concentrates from Italian ryegrass or white clover. The addition of lysine increased the value of diets containing leaf protein concentrates, possibly because the lysine present in the latter was partly unavailable through low digestibility of the proteins or chemical combination.

Nutritive value of leaf protein concentrates. II.

AbstractLeaf protein concentrates were treated in various ways in an attempt to improve their nutritive value, as measured by the “gross protein value” technique with chicks. Washing with hot water improved the value of some lucerne concentrates by removing a water‐soluble toxic factor. No appreciable improvement was obtained by: (a) varying pH of precipitation of curd, (b) different methods of drying the wet curd, or (c) solvent extraction of pigments, waxes, etc. Dried whole juice and alkali‐soluble protein had low nutritive values. The leaf protein concentrates differ considerably in “gross protein value”, but all are inferior to the better animal protein concentrates.