bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduction of the phytate content of bran by leavening in bread and its effect on zinc absorption in man
Authors: Barbro Nävert , Brittmarie Sandström , ÅKE Cederblad 
Published: September 2005

1. The effect of leavening of bread containing bran on the phytic acid content and on zinc absorption in man was studied.2. Twenty breads with leavening times varying from 0 to 120 h were prepared. The breads contained 250 g wheat bran/kg flour. The phytic acid content was determined after baking.3. The phytic acid content of bread containing bran was reduced to about 40% after 2 h of leavening and to 15 % after 2 d. No further decrease was observed.4. Zn absorption from single meals was determined using a radioisotope technique. Forty-two students volunteered for these studies. They were served a breakfast of milk, butter, bread and 10, 16 or 30 g bran served either raw or baked into the bread with fermentation times of 15 min, 45 min, 3 h or 16 h. One meal contained no bran, but phytate and Zn were added in amounts equivalent to the content of 10 g bran.5. The amount and percentage of Zn absorbed increased at each bran level as fermentation was prolonged. The percentage of Zn absorbed was reduced by increased bran content in the meal.6. It is concluded that the fermentation of bread containing bran reduces the phytic acid content and increases Zn absorption from such bread. This may be of importance to people subjected to diets with a high cereal content, especially in combination with a low animal-protein intake.
Reactions of proteins with oxidizing lipids
Authors: Nlelsen Henrik K. , Löliger J. , Hurrell R. F. 
Published: September 2005

1. The reactions between protein-bound amino acids and oxidizing lipid were investigated in a whey protein-methyl linolenate (C18.3)–water model system. The extent of fat oxidation was followed by measuring oxygen uptake, hydroperoxide formation and hydrocarbon (ethane and pentane) formation.2. Significant losses occurred with lysine (up to 71 %), tryptophan (up to 31 %) and histidine (up to 57%). Methionine was extensively oxidized to its sulphoxide but less than 2% was further oxidized to the sulphone. No other amino acids were affected.3. Increasing storage temperature (20°, 37°, 55°) resulted in an enhancement of fat oxidation reactions and amino acid degradation.4. Increasing water activity (0.28, 0.65, 0.90) increased losses of lysine and tryptophan but had no influence on the oxidation of methionine, the level of remaining hydroperoxides or 02uptake. Hydrocarbons were decreased.5. Limitation of 02uptake to 1 mol/mol lipid instead of excess 02(02uptake about 2.5 mol/mol lipid in 4 weeks) significantly reduced the degradation of lysine and tryptophan but had less influence on the oxidation of methionine. The level of remaining hydroperoxides was increased but hydrocarbons were unaffected.
Reactions of proteins with oxidizing lipids
Authors: Nielsen Henrik K. , Finot P. A. , Hurrell R. F. 
Published: September 2005

1. The consequences of reactions between protein and oxidizing lipids on the nutritional quality of food proteins have been investigated using a whey protein–methyl linolenate-water model system.2. In rat assays, significant reductions were observed in protein efficiency ratio, net protein ratio, net protein utilization, biological value and true nitrogen digestibility, especially when the reaction had taken place at high moisture content, high temperature and in the presence of excess oxygen.3. The losses of bioavailable lysine and tryptophan as measured by rat assays followed a similar pattern. The chemical value of each amino acid multiplied by the true N digestibility closely resembled the rat assay value. In general, the reaction products of lysine and tryptophan formed during lipid oxidation were biologically unavailable.4. The bioavailabilities of methionine and of ‘methionine plus cyst(e)ine’ were determined in separate assays. Cyst(e)ine was calculated as ‘methionine plus cyst(e)ine’ minus methionine. In whey protein which had reacted with oxidizing methyl linolenate, the bioavailable methionine content was not significantly reduced even though 82% of the methionine residues were present as methionine sulphoxide. In hydrogen peroxide-treated casein in which all methionine residues were oxidized to the sulphoxide, methionine sulphoxide was found to be 96% as utilizable as a methionine source to the rat. Free methionine sulphoxide was 87% utilizable.5. Cyst(e)ine appeared to be as sensitive as lysine to reactions with lipid oxidation products. In whey protein which had reacted with oxidizing methyl linolenate, the bioavailabilities of cyst(e)ine, lysine, tryptophan and methionine were reduced by 28, 24, 11 and 8% respectively and true N digestibility by 9%. These results are discussed in relation to food products.
Effect of riboflavin deficiency on lipid metabolism of liver and brown adipose tissue of sucking rat pups
Authors: Duerden Julia M. , Bates C. J. 
Published: September 2005

1. An increase in 1iver:body-weight and in hepatic triacylglycerol content, together with changes in the fatty acid profiles of hepatic phospholipids, were observed as a result of moderate riboflavin deficiency in sucking rat pups. Oxygen consumption by hepatic mitochondria, with palmitoyl L-carnitine as substrate, was not significantly impaired.2. Mitochondria from interscapular brown adipose tissue, however, showed a marked impairment of O2Consumption, with palmitoyl L-carnitine as substrate, in the riboflavin-deficient pups. This impairment was also apparent after uncoupling with carbonyl cyanidep-trifluoromethoxyphenylhydrazone, but was not consistently observed after the addition of GDP to suppress uncoupled oxidation. It was much less evident, and did not reach statistical significance, for the mitochondria of brown adipose tissue of the corresponding deficient dams.3. Binding of3H-labe11ed GDP by brown adipose tissue mitochondria was unaffected by riboflavin deficiency in the pups, suggesting that the effect on O2consumption is more likely to be due to impaired integrity of the mitochondrial respiratory chain, than to impairment of the specific capacity for uncoupling of respiration which is characteristic of brown adipose tissue mitochondria. Total cytochromecoxidase (EC 1.9.3.1) activity of the brown adipose tissue of riboflavin-deficient pups was not significantly reduced.4. A small but significant impairment was observed in the stimulation ofwhole-body O2consumption by injected noradrenaline in the riboflavin-deficient pups, suggesting that the impairment of brown adipose tissue mitochondrial function may be accompanied by impaired physiological capacity in vivo.
Feeding frequency for lactating cows: effects on digestion, milk production and energy utilization
Authors: Sutton J. D. , Broster W. H. , Napper D. J. , Siviter J. W. 
Published: September 2005

1. The results are reported of four feeding experiments in which lactating cows were given fixed rations of hay and high-cereal concentrates at different meal frequencies. In Expt 1 the total ration was given in two and twenty-four meals daily and in Expts 2–4, the concentrates were given in two and five or six meals and the hay was given twice daily. The diets contained 600–900 g concentrate /kg.2. In all the experiments, more frequent feeding of these low-roughage diets reduced milk fat depression and increased milk fat yield. In each experiment the increase was greater with the diet containing the lower proportion of hay. There was no significant effect on milk yield, the protein or lactose contents of the milk or live-weight gain. Digestibility of dry matter, organic matter and energy was increased in one of the experiments but not in two others in which it was measured.3. More frequent feeding was calculated to increase the net energy secreted in milk and there was a tendency for it to increase the net energy in live-weight gain with diets containing 600 or 700 g concentrate/kg but to decrease it with diets containing 800 or 900 g concentrate/kg. These results are discussed in relation to theories of energy partition in lactating cows.4. It is concluded that at fixed feed intakes, the main response to increased meal frequency is likely to be a reduction in milk fat depression and that this will be confined to diets containing not more than about 200 g modified acid-detergent fibre/kg dry matter.
Influences of cold exposure on digestion of organic matter, rates of passage of digesta in the gastrointestinal tract, and feeding and rumination behaviour in sheep given four forage diets in the chopped, or ground and pelleted form
Authors: Kennedy P. M. 
Published: September 2005

1. Sixteen sheep, each fitted with cannulas in the rumen and proximal duodenum, were given four diets in the chopped or ground and pelleted form, at fixed intakes at intervals of 2 h. The sheep were closely shorn and exposed to temperatures of 22–25° or 1–4° for four periods of 45 d. Flow of duodenal digesta by reference to the markers CoEDTA and 103Ru-phenanthroline, chewing behaviour and particle size of rumen and duodenal digesta were measured.2. Apparent digestibility of organic matter (OM) in the gastrointestinal tract was depressed (P < 0.05) by grinding and pelleting the diet, and by exposure of sheep to cold ambient temperatures. This was attributable to depression (P < 0.01) by 0.1 of OM digestion in the reticulo-rumen. No effects on intestinal digestion of OM were observed.3. Cold ambient temperatures did not affect the content, but increased the rate of digestion for pelleted diets but not for chopped diets, of potentially-degradable cell-wall constituents of ground dietary material incubated in nylon-bags in the rumen.4. Retention times of markers of the particulate and liquid phases of rumen digesta were not significantly (P < 0.05) affected by ambient temperature, despite significant (P < 0.001) increases in the rate of contraction of the reticulum. Retention time of 103Ru-phenanthroline in the intestines was not affected by cold exposure.5. Cold exposure was associated with depression (P < 0.05) of volatile fatty acids concentration in the rumen and elevated (P < 0.05) pH. Molar proportions of acetic and isovaleric acid were reduced (P < 0.01), accompanied by increased (P < 0.001) proportions of propionic acid during cold exposure.6. Cold exposure and pelleting of the diets were both associated with reduction in digesta particle size in the rumen. Duodenal particle size was not affected by cold exposure. Pelleting of the diet markedly reduced (P < 0.001) duration of chewing and number of chews/d during eating and rumination. Cold exposure of sheep resulted in a faster (P < 0.01) rate of eating of the diets.7. When allowed to express their voluntary feed consumption during a 10 d period, intakes of chopped diets were increased by 0.13 (P < 0.01) by cold exposure, in contrast to lack of significant change in sheep given pellets.8. The results did not support the hypothesis that the effect of cold exposure on digestion was dependent on the physical form of the diet given at fixed intake, but did indicate that increased voluntary feed consumption was a result of increased clearance of digesta from the rumen throdgh decreased rumen particle size and increased reticulum motility.
Cellulose and pectin alter intestinal β-glucuronidase (EC 3.2.1.31) in the rat
Authors: Lindop Rosemary , Tasman-Jones Clifford , Thomsen Lindy L. , Lee Sum P. 
Published: September 2005

1. Groups of rats were given a fibre-free diet containing none or one of the three fibre components: pectin, cellulose or galactomannan.2. After feeding for 16 weeks, total protein level and β-glucuronidase (EC 3.2.1.31) activity in the contents and mucosa of jejunum and ileum, and in the contents only of the caecum, were determined.3. The pectin supplement reduced protein concentration in jejunal contents while cellulose reduced protein concentration in the ileal and caecal contents.4. β-Glucuronidase activity of caecal contents was significantly reduced in both the pectin- and cellulose-fed groups.5. Cellulose affected the β-glucuronidase activity of both the ileal contents while pectin reduced the β-glucuronidase of the ileal but not the jejunal contents.6. Dietary fibre components did not significantly affect jejunal or ileal mucosal β-glucuronidase activity.
The effect of guar gum and level and source of dietary fat on glucose tolerance in growing pigs
Authors: Sambrook Ian E. , Rainbird Anna L. 
Published: September 2005

1. Six growing pigs (30–75 kg) were fed on semi-purified diets containing either 30 g maize oil/kg diet (LFM), 30 g soya-bean oil-tallow mixture (1:1, w/w)/kg diet (LFST) or 160 g soya-bean oil-tallow mixture (1:1, ww)/kg diet (HFST) without and with the addition of guar gum (40g/kg diet).2. Plasma glucose and insulin concentrations following twice daily feeding at 09.00 and 21.00 h were measured, during 24 h periods, in blood sampled from a permanent indwelling vena cava catheter.3. The source and level of dietary fat had no significant effect on pre-prandial plasma glucose or insulin concentrations except for insulin with diet LFST in the morning (P<0.05). Addition of guar gum to the diets had no significant effect on pre-prandial plasma glucose and insulin levels.4. The peak post-prandial plasma glucose and insulin levels were not significantly affected by dietary fat. The addition of guar gum, however, significantly reduced (P < 0.05) the peak post-prandial plasma glucose concentration with diets LFM and LFST and also the peak plasma insulin concentration for all diets except for diet HFST in the morning.5. The time taken to reach the peak post-prandial plasma glucose and insulin concentrations was not significantly affected by dietary fat but it was increased by the addition of guar gum, although the differences were not always significant.
Dietary effects on pancreatic lesions induced by excess arginine in rats
Authors: Takama Shigeyuki , Kishino Yasuo 
Published: September 2005

1. The effect of nutrition on the incidence of pancreatic damage was studied. Injection of excess arginine was found to cause more massive necrosis of the acinar cells after 24 h in malnourished rats (those given 50 g casein/kg diet) than in well-nourished rats (those given 200 g casein/kg diet).2. Ultrastructural examination showed that whorl formation of the endoplasmic reticulum, decreases in the number of zymogen granules and formation of vacuoles in the cytoplasm were more marked in rats given 50 g casein/kg diet. Degradation of zymogen granules within vacuoles in the damaged cells was frequently observed in rats given 200 g casein/kg diet.3. Necrosis of adipose tissue was associated with pancreatic damage more frequently in rats given 200 g casein/kg diet; rats with large amounts of zymogen granules in the acinar cells showed particularly severe necrosis of adipose tissue. Rats given 50 g casein/kg diet did not show necrosis of adipose tissue.4. These results indicate that in the malnourished state there were more marked arginine lesions of the pancreas in which to study cellular and histologic changes than in the well-nourished state and that the occurrence of necrosis of adipose tissue may be related to a high content of zymogen granules in the acinar cells before pancreatic damage.
The influence of creatinine, lecithin and choline feeding on aliphatic amine production and excretion in the rat
Authors: Lowis Susan , Eastwood M. A. , Brydon W. G. 
Published: September 2005

1. The excretion of aliphatic amines, methylamine, dimethylamine and trimethylamine in the urine and faeces of rats fed on a control diet and diets supplemented with creatinine, lecithin or choline were measured over a 14 d feeding period.2. The rats were then killed and concentrations of amines in small and large intestinal contents measured.3. Adding creatinine to the diet resulted in a significant increase of methylamine excretion in the faeces and urine. The amount of methylamine found in all parts of the intestine increased, especially in the caecum.4. Adding lecithin to the diet resulted in an increase in the methylamine excretion only, and no change in the concentrations of amines found in the intestine, except for trimethylamine which was significantly increased in the caecum and colon.5. Adding choline to the diet resulted in a significant increase in excretion of trimethylamine and, to a lesser extent, methylamine. The levels of amines found in the gut increased, dimethylamine being increased in the small bowel, and methylamine and trimethylamine in the caecum.
Intestinal absorption of sorbitol and effects of its acute administration on glucose homeostasis in normal rats
Authors: Lauwers A.-M. , Daumerie C. , Henquin J. C. 
Published: September 2005

1. Intestinal absorption of sorbitol was studied in a duodeno-jejunal loop of anaesthetized rats. The acute effects of exogenous sorbitol on glucose homeostasis were also evaluated in male and female rats.2. In the presence of lumen concentrations of sorbitol ranging from l μM to 200mM, a fairly constant low percentage (about 12%) of the loop's contents was absorbed after 30 min. This amount increased only slightly with time, but this was not due to sorbitol accumulation in the mucosal layer of the loop.3. 3-O-methylglucose was absorbed much more quickly than sorbitol, but did not interfere with sorbitol absorption. The latter was not impaired by omission of lumen sodium ions nor by phloridzin, both of which inhibited 3-O-methylglucose absorption.4. Gastric administration of sorbitol did not affect plasma glucose or insulin levels. Glucose or sucrose administration caused a similar rise in plasma glucose, but the increase in plasma insulin levels was larger after glucose than after sucrose administration.5. Intravenous administration of sorbitol slightly increased plasma glucose and insulin levels. These changes were, however, considerably smaller than those occurring after glucose administration.6. In the normal rat, intestinal absorption of sorbitol is passive and proceeds at a low rate. Acute oral administration of sorbitol does not affect glucose homeostasis, which is only slightly disturbed by a large intravenous load of sorbitol.
α-1-Antitrypsin metabolism in the protein-deficient weanling rat
Authors: Lewis Eric C. , Glew Robert H. , Chambers James , Coyle Patrick , Coppes Jhon 
Published: September 2005

1. Protein-deficient weanling rats fed on a 30 g casein/kg diet for 3 weeks lost albumin but maintained the level of serum α-1-antitrypsin, the most abundant protease inhibitor in blood.2.α-1-Antitrypsins from malnourished rats and control rats (given 250 g casein/kg diet) differed; the protease inhibitor from protein-deficient animals: (1) was more acidic, (2) appeared slightly larger (57400 v. 56000 daltons) on sodium dodecyl sulphate (SDS)-polyacrylamide gels, (3) had a more acidic Pitype and increased anodal mobility at pH 8.9, (4) bound more concanavalin-A and contained more carbohydrate, specifically two to three extra sialic acid residues. The amino sugar and neutral sugar contents of both preparations of α-1-antitrypsin were the same.3. Analysis of the products of cyanogen-bromide cleavage revealed that α-1-antitrypsin preparations from protein-deficient rats contain an extra glycopeptide that was not present in α-1-antitrypsin from control animals.4. In vivo studies showed that the increased sialic acid content of α-1-antitrypsin of protein-deficient rats did not alter the half-life of the molecule in the blood of control rats. However, the fractional catabolic rate of α-1-antitrypsin from either well-nourished or protein-deficient rats was significantly (P < 0.01) lower in protein- deficient rats than in control rats (0.0247/h v. 0.0406/h).5. The decreased fractional catabolic rate could not be explained by changes in hepatic mannosyl-, galactosyl- or N-acetylhexosaminyl receptors since liver perfusion studies showed that bovine serum albumin, when covalently modified separately with each of these ligands, was extracted from the perfusion medium as rapidly or more rapidly by livers from malnourished animals.6. Perfused livers from protein-deficient rats secrete three times more α-1-antitrypsin than do livers from well-nourished animals.7. The decreased fractional catabolic rate and increased rate of biosynthesis and secretion of the glycoprotein by livers from protein-deficient animals may account for the maintenance of α-1-antitrypsin levels during protein malnutrition.
The importance of the non-protein components of the diet in the plasma cholesterol response of rabbits to casein
Authors: Allotta E. C. , Samman S. , Roberts D. C. K. 
Published: September 2005

1. To characterize the hypercholesterolaemic effect of casein further, four groups of young male rabbits in two separate experiments were placed on cholesterol-free semi-purified diets for 12 weeks. The diets were similar in composition, with either casein or soya-bean-protein isolate providing the protein source (250 g/kg). In two of these diets the salt mix was reduced by 45% (normally 40 g/kg) and replaced by potassium bicarbonate.2. Growth was unaffected by these alterations in dietary salts except for one group given the soya-bean-reduced-salts diet.3. The mean concentrations of plasma cholesterol were significantly higher in all casein-fed groups as compared with their soya-bean-fed counterparts but the response was much greater in those given the casein—reduced-salts diet.4. Contrary to expectations, analysis of the diets showed the zinc and copper concentrations of the casein diets to be less than those of the soya-bean diets. This was due to the greater concentrations of Cu (threefold) and Zn (twofold) in the soya-bean-protein isolate compared with casein.5. The mean concentration of Zn in fur was significantly decreased in casein-fed rabbits and these animals also excreted less Zn but more Cu in their urine than those given the casein—reduced-salts diet.6. The rabbits given the casein diet with the least salt mix showed the greatest degree of hypercholesterolaemia, suggesting an interaction between trace elements and the casein effect.
The effect of increasing methionine supply on the methionine conversion to cyst(e)ine in sheep
Authors: Pisulewski P. M. , Buttery P. J. 
Published: September 2005

1. The conversion of methionine to cyst(e)ine was determined in sheep infused with different amounts of methionine (0-5 g/d) into the duodenum by assaying the incorporation of36S from intravenously-infused L-[35S]methionine into cyst(e)ine in wool, plasma albumin and the free plasma pool.2. The percentage of cystine-S in the plasma originating from methionine increased linearly from 4.5 to 18 with increasing supplemental methionine supply.3. The percentage of cysteine-S in albumin increased from 15 to 50; methionine supply increased to 3 g/d but then remained constant, indicating that the transsulphuration pathway of the liver was exceeded.4. The percentage of wool cysteine-S originating from methionine was high (∼ 70) at all methionine supplementation rates.