Protein Content Of Meal Research Articles

Growth, digestive enzyme activities and hepatic glycogen levels in juvenile Colossoma macropomum Cuvier from South America during feeding, starvation and refeeding

Abstract. Feeding trials with juvenile Colossoma macropomum Cuvier (approximately 40g) were carried out to study their protein requirements and their efficiency in metabolizing vegetable protein. Two groups of diets were used. In one group, the crude protein consisted exclusively of fish protein concentrate. In the second group the protein consisted of a mixture (55:45) of vegetable and animal protein without fish meal. In each group 30 and 50% protein levels were used. The highest weight increase (1·64%/day) and the lowest feeding rate were obtained with the 50% protein fish meal free diet. During the trial all fish accumulated visceral fat while body protein content decreased and dry matter increased. There was a high correlation between liver weight and liver glycogen. The highest amounts of liver glycogen were induced by diets containing fish meal and/or low protein content. In contrast lo visceral fat deposits, accumulated liver glycogen was of less significance for surviving starvation periods. The activity of digestive enzymes depends on both stomach and gut fullness. Trypsin activity, contrary to pepsin, was correlated with diet protein content, a-amylase activity was not correlated with diet composition.

Processing of canola meal for incorporation in trout and salmon diets

Canola meals (two commercial meals and one low‐heat meal) were processed to reduce fiber content, then washed with selected solvents to reduce the content of antinutritional substances and further concentrate protein. The meals, fiber‐reduced meals, and washed meals were used to provide 40% of total protein (26–38% of feed) in the diets of 6‐g rainbow trout for 3 weeks or 25% of total protein (21–31% of feed) in the diets of 23‐g chinook salmon for 11 weeks. Air‐desolventized (low‐heat) canola meal, as compared to commercial meal, provided no protein quality advantage in trout feeds. Fiber reduction processing of commercial meal increased meal protein content by 11–16% and reduced crude fiber by 23–50%, but did not have any effect on the quality of protein for trout or salmon. Solvent‐washing of fiber‐reduced meal improved fish response to canola meal, probably due to reduced glucosinolate content, but possibly also due to reduced sinapine content and alterations in protein availability. Protein concentration was increased by 25–40% by washing, and glucosinolate concentration was reduced by 40–90%.

Alto summer rape

Alto summer rape (Brassica napus L.), registered in 1988, is a canola-quality cultivar. Alto has a high meal protein content and is similar to the cultivar Westar in seed yield, oil content, and maturity. Alto is adapted to all of the B. napus growing areas in western Canada. Key words: Rape (summer), cultivar description

Production of phytase by Aspergillus ficuum and reduction of phytic acid content in canola meal

AbstractProduction of the phytase (EC 3.1.3.8) from Aspergillus ficuum in a submerged batch process was inhibited by high concentrations of glucose. The inhibition was overcome by applying a fed batch technique in the production of the enzyme. Tests carried out at different oxygen concentrations revealed that aeration had a beneficial effect on the production of the enzyme. The enzyme showed an optimum pH and temperature of 5·0 and 60°C, respectively. Preincubation of the enzyme preparation at 60°C resulted in relatively fast denaturation of the enzyme. Upon storage at 4°C it lost only 15% of its activity in 5 weeks. Aspergillus ficuum also produced phytase when grown on canola meal by a solid state technique. The enzyme catalysed degradation of the phytic acid present in the meal and completely eliminated it, rendering the commodity more suitable for animal feed. An apparent 10% increase in protein content of the canola meal was noted as a result of the growth of the microorganism.

THE EFFECTS OF 2-CHLORO-6 (TRICHLOROMETHYL)-PYRIDINE (’N-SERVE’) AND N FERTILIZERS ON PRODUCTIVITY AND QUALITY OF CANADIAN OILSEED RAPE

’N-Serve’ has been shown to reduce losses of applied N-fertilizer and thereby increase fertilizer N-utilization by plants. This study was undertaken to test the effects of ’N-Serve’ on fertilizer N efficiency in oilseed rape production and quality. Field experiments were conducted on two chernozemic soils over 4 yr in Manitoba. The oilseed rape cultivars Tower (Brassica napus L.) and Torch (B. campestris) were used in the study. Spring and fall applied ammonium nitrate, urea and fluid-N, with and without ’N-Serve’ delayed flowering and increased the herbage yield of both oilseed rape cultivars. The number of days from full pod to maturity was increased with application of N fertilizers, but the number of days from flowering to full pod was constant. Increased herbage yield and total plant N at flowering was reflected in increased seed yield and meal protein content, but decreased oil content. ’N-Serve’ applied with and without N fertilizer reduced oil content and oil yield. However, when ’N-Serve’ was applied in the fall with urea and fluid-N it improved their efficiency, resulting in higher seed yields and meal protein content equivalent to that of spring applications. ’N-Serve’ used with fall applied ammonium nitrate or with all three sources of spring applied N had no similar effect. It is concluded that ’N-Serve’ should not be applied to oilseed rape, mainly because of its negative effect on seed oil content.Key words: Oilseed rape, ammonium nitrate, urea, fluid-N, chernozemic soil, protein, oil

Standardization of Electrode Positioning and Composition of Meals for Long-Term Intragastric pH Metry in Man

In these prospective studies the influence of two different intragastric positions of electrodes and of four different compositions of standardized meals on 24-hour ambulatory pH recording were compared intraindividually in healthy male subjects. Simultaneous pH monitoring in 12 subjects demonstrated a more pronounced postprandial pH elevation in the fundus body compared to the antral area. The intraindividual comparison of an identical diet given on two different days to 10 subjects revealed nearly identical pH profiles. Variations of carbohydrate, protein and fat content of isocaloric meals given in a randomized order did not significantly alter 24-hour intragastric pH profiles. It is concluded from these data that positioning of the pH electrode in the fundus body area is superior to an antral position. 24-hour ambulatory intragastric pH monitoring in man is well reproducible. A strict standardization of the composition of meals is mandatory only for scientific investigations.

Breeding Soybeans for the Economic Values of Seed Oil and Protein

The monetary value of meal has exceeded that of oil from a bushel of U.S. soybeans in 28 of the past 30 yr. Yet we continue to produce soybeans with higher oil and, consequently, lower protein content. This paper considers, theoretically, the biological and economical aspects of breeding soybeans for oil and protein content and seed yield. All assumed genotypes are compared with a “standard” soybean (18% oil, 35.86% protein at 13% moisture). Varying rates of loss or gain in protein per unit gain or loss in oil and varying ratios of oil to 44% meal prices are assumed. Chemical constituent values (CCV, the economic value of oil plus protein) of the seed of soybean genotypes varying in seed oil and protein content were determined by the formulae of Updaw and Nichols. Continuation of present breeding programs emphasizing increased seed yields will probably result in increased oil and decreased protein content of seed. High yielding, 20% oil-34% protein soybean cultivars are now available. Assuming a 1:1 tradeoff of protein for oil, a 22% oil, 32% protein soybean may be achievable by breeding for high oil and/or high yield. Meal protein content is a function of seed oil and protein. The rate of protein loss as oil increases must be minimized in order to maintain current minimum standard specifications of protein content of meal. The high protein-lower oil soybean with highest CCV will be achieved with maximum gain of protein per unit loss of oil as compared to the standard soybean. High protein-lower oil soybeans are higher in CCV/bu than either standard or high oil-lower protein soybeans when soybean oil is less than three times the value of 44% meal. The big constraint on the high protein-lower oil soybean to date is lower yielding ability. The yielding ability of high protein-lower oil soybeans must approach that of standard or high oil-lower protein soybeans to be competitive on a CCV/acre basis. High oil-high protein-high yielding soybeans are probably not achievable by conventional breeding methods but may be attainable by biotechnological approaches.

Threonine entry into rat brain after diet-induced changes in plasma amino acids.

Passage of amino acids across the blood-brain barrier is modified by the amino acid composition of the blood. Because blood amino acid concentrations respond to changes in protein intake, we have examined associations among diet, plasma amino acid patterns, and the rate of entry of threonine into the brain. Rats were adapted for 8 h/day for 7-10 days to diets containing 6, 18, or 50% casein before receiving a single, independently varied, final meal of a diet containing 0, 6, 18, or 50% casein. After 4-7 h, they were anesthetized and infused intravenously with [14C]threonine for 5 min before plasma and brain samples were taken for determination of radioactivity and amino acid content. Plasma and brain threonine concentrations decreased as protein content increased in the diets to which the rats had been adapted. Plasma threonine concentrations increased twofold, from 1.6 to 3.0 mM, when rats adapted to 6% casein meals received a single 50% casein meal rather than a nonprotein meal; a fivefold increase, from 0.13 to 0.69 mM, occurred when rats had been previously adapted to 50% casein meals. Increasing the protein content of the final meal did not increase brain threonine concentrations. Highest and lowest rates of threonine entry into the brain occurred, respectively, in rats adapted to 6 and 50% casein meals. Changes in plasma threonine concentrations and threonine flux into brain reflected protein content of both pretreatment and final meals.

Metabolic effect of pre-cooked instant preparations of bean and potato in normal and in diabetic subjects

The effect of a 50 g starch meal prepared with pre-cooked instant bean flakes on glucose and insulin plasma levels and on glucose oxidation rate as measured by continuous indirect calorimetry was assessed in six healthy human volunteers during 4 h following the meal. Comparison was done with the same load of starch as potato flakes to which the fiber and protein content of the bean meal had been added. Thirty minutes after ingestion, plasma glucose and insulin rise was less after beans than after potatoes (0.4 ± 0.2 vs 2.0 ± 0.3 mmol·1−1, p < 0.01, and 8 ± 2 vs 38 ± 5 µU · ml−1, p < 0.001). The elevation of glucose oxidation was markedly less during the 2 h following the ingestion of beans when compared to potatoes. The bean flakes meal gave rise to only moderate elevation of plasma glucose and insulin levels and of glucose oxidation rate when given to four non-insulin-dependent-diabetes mellitus patients. It is suggested that the slow carbohydrate property of legumes is not due to their fiber content, but might be related to the histological structure of the seed.

True Metabolizable Energy and Total and Available Amino Acids of Candle, Altex, and Regent Canola Meals

Prepress solvent extracted canola meals of Brassica campestris cv. Candle and B. napus cv. Altex and Regent and expeller processed Candle meal were analyzed for crude protein (N × 6.25), ether extract, glucosinolates, true metabolizable energy (TME), amino acids, and amino acid availability. Except for the higher protein content of Regent meal and increased ether extract and TME content of expeller over prepress solvent processed meals, the cultivars were similar in composition and amino acid availability. The TME values of the prepress solvent meals ranged from 10.2 to 10.6 kJ (2.44 to 2.54 kcal)/g dry matter compared with 11.4 kJ (2.72 kcal)/g for expeller processed meal.

Compositional and metabolic changes in brown adipose tissue following a single test meal

In rats maintained on a scheduled feeding plan, the hypertrophy of brown adipose tissue (BAT) observed after a low-protein/high-carbohydrate single test meal was accompained by significant changes in the percentage of all major constituents of the tissue. There was a fall in the percentage of water ( P < 0.01), a rise in the percentage of fat ( P < 0.05), and a rise in the percentage of glycogen ( P < 0.001). The largest absolute changes following a meal were in the fat content, which almost doubled, and in the glycogen content, which exhibited about a four-fold increase. Deposition of fat in the BAT following the test meal was accompanied by a three-fold increase in the rate of fatty acid synthesis ( P < 0.05). The in vitro respiration rate of BAT was usually significantly increased in the meal-fed rats, but the effect of replacing the protein content of the test meal with starch was not clear. A lower protein, higher starch diet (9% of calories from protein, 72% from starch) resulted in a trend for a larger thermic effect than a higher protein, lower starch diet (27% of calories from protein, 54% from starch).

Changes in brain levels of acidic, basic, and neutral amino acids after consumption of single meals containing various proportions of protein.

Rats fasted overnight were allowed to consume single meals containing 0, 18, or 40% protein or continued to fast; after 2 h, brains and sera were taken and assayed for various amino acids. In general, serum levels of most amino acids were reduced by the 0% protein meal and elevated by the high-protein meal when compared with those associated with fasting conditions. Exceptions were those not diminished by the 0% protein meal (tryptophan, methionine, proline) and those increased (alanine) or decreased (glycine) by all of the test meals. Amino acids exhibiting the broadest normal ranges (estimated by comparing their serum levels after 40% protein with those after 0% protein) were tyrosine, leucine, valine, isoleucine, and proline; serum lysine and histidine, two basic amino acids, also varied more than threefold. Brain levels of lysine, histidine, and some of the large neutral amino acids (LNAAs) also exhibited clear relationships to the protein content of the test meal: those of valine, leucine, and isoleucine were depressed by the 0% protein but increased (compared with 0% protein) when protein was added to the meal: brain tyrosine was increased by all of the test meals in proportion to their protein contents; tryptophan, phenylalanine, and glutamate were increased after the 0% protein meal but not by protein-containing meals; brain lysine, histidine, and methionine were increased after the high-protein meal, and brain alanine was increased slightly by all of the meals.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein enrichment of cassava root meal by trichoderma harzianum for animal feed

AbstractA fermentation procedure to increase the protein content of cassava root meal (CRM) with Trichoderma harzianum is described. The organism was grown in a 4% CRM medium with inorganic nitrogen. The fungal biomass plus the rest of CRM were collected by filtration at the end of fermentation. Satisfactory results were obtained at 23 °C (pH 4.0‐4.2) and a fermentation time of 60 h. The CRM/biomass contained about 38% crude protein (CP) on a dry matter basis. This should be compared with 2.4% CP in the untreated CRM. The sum of amino acids in the product corresponded to about 60% of the CP value. The estimated efficiency of conversion of the CRM into CRM/biomass was found to be about 30%. A substantial improvement in the protein content and quality of CRM can be made through submerged cultivation of T. harzianum on CRM.

Protein quality studies on rats fed on cassava-root meal enriched with Cephalosporium eichhorniae 152 or with conventional plant-protein supplements

Using rats, the protein content and quality of an enriched cassava-root meal (CRM) biomass, produced by growing Cephalosporium eichhorniae 152 on a CRM medium in a submerged fermentation, was compared with that of soya-bean meal (SBM) and cotton-seed cake (CSC) in rats. The contents of crude protein of these feeds were 38.8, 52.0 and 42.3% on DM basis, respectively, and there were differences in their amino acid composition. The nitrogen digestibility of the enriched CRM-biomass and of CSC was lower than that of SBM. The biological value of the enriched CRM-biomass was equal to that of CSC, but lower than that of SBM. Net protein-utilization estimates for the enriched CRM-biomass and for CSC were similar, whereas that for SEM was greater. Enriching CRM by C. eichhorniae 152 seems to be a way of increasing protein supply for livestock production.

Zinc absorption from composite meals I. The significance of wheat extraction rate, zinc, calcium, and protein content in meals based on bread

The absorption of zinc in man from composite meals based on bread was measured with a radionuclide technique using 65Zn and whole-body counting. Bread was made up from wheat flour of 100 and 72% extraction rate. A lower absolute amount of zinc was absorbed from the white bread compared to the absorption from the same amount of wholemeal bread. When the two types of bread were enriched with zinc chloride the absorption was higher from the white bread than from the wholemeal bread. Addition of calcium in the form of milk products improved the absorption of zinc from a meal with wholemeal bread. A significant positive correlation was found between zinc absorption and the protein content in meals containing milk, cheese, beef, and egg in various combinations with the wholemeal bread.

Response of Wild Oat (Avena fatua), Flax (Linum usitatissimum), and Rapeseed (Brassica campestrisandB. napus)to Diclofop-methyl

Diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} applied as postemergence treatment at rates of 0.84 to 1.68 kg/ha controlled 65 to 87% of the wild oat (Avena fatuaL.) without injuring flax (Linum usitatissimumL.) or rapeseed (Brassica campestrisL. andB. napusL.) Yields of both crops were significantly increased because wild oat competition was minimized. Wild oat control was further improved when adjuvants were added with the herbicide at a concentration of 0.5% (v/v) to the spray mixture. Oil content, iodine number, and linolenic acid concentration of flax, and oil content of rapeseed were increased with the application of the herbicide, while the protein content of meal from both crops was unaffected. When flax was grown in the greenhouse under weed-free conditions, the 0.84 and 1.12 kg/ha rates of the herbicide did not affect seed and oil composition, whereas the 1.68 kg/ha rate decreased protein content, and slightly increased oil content, but had no significant effect on iodine number when compared with the untreated check. The change in seed and oil quality of flax appears to be related to a reduction in weed competition by the herbicide.

Feeding of school children in a London borough.

A survey of 12 schools in a London borough showed that the protein and energy content of the average school meal was below the standard set by the Department of Health and Social Security for all age groups. Failure to meet the standards resulted from inadequate food purchases, poor menu planning and portion control, and several management problems. A 24-hour recall questionnaire showed that 5% of the pupils were "poorly" fed. These pupils were, however, no worse off than their "adequately" fed peers with regard to absences from school or academic attainment measured by reading quotient, but there was some slight difference in height and weight. The percentage of children having no breakfast increased from 4% in the infant schools to 21% in the senior schools. Two per cent of the senior pupils regularly ate no lunch.

Evaluation of the ESCA technique as a screening method for the estimation of protein content and quality in seed meals.

AbstractThe ESCA (Electron Spectroscopy for Chemical Analysis) technique has been evaluated as an analytical screening method for the determination of protein content and quality of grain meals of some legumes and cereals. To this end the grain meals of a number of different species were analysed for total nitrogen, meals of varieties of cowpea (Vigna unguiculata) were examined for sulpho‐amino acid content, and the levels of basic amino acid in meals of some maize and barley varieties were measured by this technique; some amino acids, polyamino acids and pure proteins were also examined as standards.The results obtained for 15 grain meals by the ESCA technique, expressed as the ratio of the intensity of the N1s photoelectron signal to that of the C1s signal, were compared with %N as determined by a semi‐automated micro‐Kjeldahl method, and the correlation coefficient between the results from these two methods was r = 0.98. The binding energies of S2p electrons were determined for some amino acids and proteins, and the amino acid sulphur was differentiated from oxidised sulphur. The N1s/S2p intensity ratios for four pure proteins correlated very well with the calculated stoichiometric N/S ratios (r = 0.999). The N1s/S2p intensity ratios were also determined for seven cowpea varieties and the correlation coefficient between these values and the ratios N/Saa, measured by chemical methods, was r = 0.77.The N1s photoelectron peaks of some varieties of barley and maize meals showed a pronounced shoulder on the high binding energy side. On deconvolution into two components the main peak was assigned to nitrogen in the peptide bond and the smaller peak was assigned to the protonated nitrogen on the side chains of the basic amino acid residues.

Protein and Free Amino Acid Composition of Sesame Meal as Affected by Nitrogen, Phosphorus, and Potassium Nutrition

AbstractProtein and free amino acid composition of lipid‐free sesame (Sesamum indicum L.) meal was studied for effects of increasing substrate levels of N, P, and K in sand culture experiments. Concentrations of individual protein amino acids were increased in the seed meal with increasing substrate levels of N and K nutrition due primarily to increases in protein content. Increasing P supply had no significant effect on amino acid composition.Increasing levels of N resulted in increases in nonamino acid forms of N. Nitrogen increased individual free amino acids while P had no effect. Potassium deficiency resulted in accumulations of all individual free amino acids except cystine. These accumulations coupled with the observed decreases in protein amino acids in K‐deficient plants support the view that adequate K supply is required for proper utilization of amino acids in protein synthesis.The pattern of essential amino acids expressed as a fraction of the total essential amino acids was little affected by N, P, and K nutrition when compared to the large increases resulting from increased seed yield and meal protein content.

School meals and the nutrition of schoolchildren.

The contribution of school meals to the nutrition of 778 primary and secondary schoolchildren attending schools in Kent was assessed using information collected during a survey made in 1968-70 which included a weighed diet record, a socioeconomic questionnaire, and a medical examination. Younger children, those from larger families, those without fathers, and those whose mothers worked were more likely to take school meals. Significantly more children from lower social classes and without fathers received them free. School meals made an important contribution to the nutrition of schoolchildren. Children who took them had higher weekday lunchtime nutrient intake during term-time. Children in lower social classes, larger families, and without fathers who took school meals obtained a higher proportion of their weekday intake of nutrients from lunchtime than other children. This applied in particular to nutrients important for growth. School meals consumed by children in the study broadly met the standard set by the Department of Education and Science. The mean energy and protein content of school meals consumed in the study was slightly lower and the mean fat content higher than the standard set for the meal. The mean sugar content was about one-third higher than the suggested amount of sugar to be included in a school meal. There was no evidence that children who took school meals were taller, heavier, had greater skinfold thickness, or were more likely to be assessed as obese than other children.