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At least 1,711 records · Page 95Linked to original sources
PubMed1992

Volatile compound content and fatty acid composition of pork as influenced by linoleic acid content of the diet.

Eighty pigs (average weight of 60 kg) were allotted by weight and sex to pens and treatments. There were four dietary treatments, five pens per treatment, and four pigs per pen. Diets consisted of a typical corn-soybean mix containing 9% total fat, 3% from the corn-soybean mix and 6% added. The four dietary treatments included 1) 6% safflower oil, 2) 4% safflower oil and 2% tallow, 3) 2% safflower oil and 4% tallow, and 4) 6% tallow, resulting in 6.1, 4.6, 3.2, and 1.76% linoleic acid, respectively, in the diet. Pigs were slaughtered at an average weight of 100 kg. Proximate composition, tristimulus color coordinates (L, a, and b values), pH, and flavor difference of the longissimus muscle (LM) were evaluated. Fatty acid content (milligrams per 100 grams of tissue) of the subcutaneous fat and LM and headspace volatile content of the LM were determined by capillary gas liquid chromatography. Proximate composition, color, pH, and flavor of the LM were not influenced by diet. Fatty acid content of the subcutaneous fat and LM and volatile content of the LM were influenced by diet. Increased levels of safflower oil in the diet resulted in less C16:0 and C18:1 and more C18:2, C20:2, and C20:3 in the subcutaneous fat. The LM contained more C18:2 and less C18:3 and C24:0 due to increased levels of safflower oil in the diet. Compared with the 6% tallow diet, LM from pigs fed the 4 or 6% safflower diets contained more pentanal, hexanal, 2-heptanone, trans-2-heptenal, 2-pentyl furan, 2-ethyl-1-hexanol, decanal, and undecanal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed2002

Characterization of microbial populations and volatile fatty acid concentrations in the jejunum, ileum, and cecum of pigs weaned at 17 vs 24 days of age.

In a series of five 17-d replicate trials, a total of 54 cannulated and 12 noncannulated pigs were used to determine the effects of weaning age (17 d or 24 d) on pH, dry matter percentage, aerobic and anaerobic microflora, lactate, and volatile fatty acid (VFA) concentrations in the jejunum, ileum, and cecum of weanling pigs. At -14 d of age, cannulated pigs were surgically fitted with T-cannulas in the jejunum (n = 20), ileum (n = 18), or cecum (n = 16). Upon weaning, cannulated pigs were individually caged in an environmentally controlled room with ad libitum access to a phase starter diet and water. Noncannulated pigs were killed at weaning and samples were collected from the jejunum, ileum, and cecum. Digesta and fecal swabs from cannulated pigs were collected twice weekly. The pH of cecal contents was lower (P < 0.05) and dry matter percentage was greater (P < 0.05) than those ofjejunal or ileal contents. Pigs weaned at 24 d of age had increased (P < 0.05) E. coli populations 3 d postweaning compared to preweaning populations, regardless of site of collection, whereas this increase was not observed in pigs weaned at 17 d of age. Unweaned pigs maintained higher (P < 0.05) lactobacilli populations compared to weaned pigs; however, populations declined (P < 0.05) in both groups by 3 d postweaning, with pigs weaned at 24 d of age having lactobacilli populations greater than pigs weaned at 17 d of age. Fecal populations of E. coli and lactobacilli declined (P < 0.05), whereas fecal bifidobacteria populations increased (P < 0.05) postweaning, regardless of weaning age. Concentrations of total fecal anaerobes declined (P < 0.05) in pigs weaned at 17 d of age but were maintained in pigs weaned at 24 d of age. Volatile fatty acid concentrations were greater (P < 0.05) in the cecum than in the jejunum or ileum, and acetic acid concentrations decreased (P < 0.05) postweaning regardless of weaning age. A tendency for L+ lactate concentrations to be greater (P < 0.07) in the ileum and jejunum vs the cecum was observed. Results indicate that weaning and weaning age have significant effects on microbial populations and VFA concentrations.

Age Factors↗
PubMed1987

Influence of supplemental four- and five-carbon volatile fatty acids on forage intake and utilization by steers.

Four ruminally and duodenally cannulated crossbred steers (avg wt 282 kg; trial 1) and 12 intact Hereford steers (avg wt 336 kg; trial 2) were used to evaluate the effects of supplemental four- and five-carbon volatile fatty acids (SFA) on intake and digestion of low-quality prairie grass hay (PH). Steers were fed PH at 1.8% body weight (trial 1) or free choice (trial 2) together with a 34% protein, urea-cottonseed meal supplement (365 g/d trial 1; 500 g/d trial 2) plus 0 or 30 g/d of SFA (Ca-salts of isoC4, C5, and isoC5 acids). Ruminal pH, ammonia-N and total volatile fatty acid concentrations were not influenced (P greater than .10) by SFA. Addition of SFA increased the molar proportions of isobutyric (.84 vs .11; P less than .05), isovaleric (1.01 vs .32; P less than .01), and valeric (.66 vs .47; P less than .07) acids but did not significantly alter the proportions of other acids. Apparent total tract organic matter digestion (51.9 vs 53.7%; P = .095) tended to decrease with SFA, while ruminal and total tract digestion of acid detergent fiber and N were not affected by SFA. Microbial N (MN) flow to the duodenum and efficiency of microbial crude protein (MCP) synthesis were similar for both treatments (66.7 vs 57.4 g MN/d and 29.8 vs 24.4 g MCP/100 g apparently fermented organic matter, respectively). In trial 2, total tract dry matter and acid detergent fiber digestion and voluntary intake were similar for both diets. Results suggest that intake and utilization of prairie hay was not limited by a ruminal deficiency of SFA.

Animal Feed↗
PubMed1985

Enhanced metabolism of volatile hydrocarbons in rat liver following food deprivation, restricted carbohydrate intake, and administration of ethanol, phenobarbital, polychlorinated biphenyl and 3-methylcholanthrene: a comparative study.

The effects of food deprivation, carbohydrate restriction and ethanol consumption on the metabolism of eight volatile hydrocarbons (benzene, toluene, styrene, chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethylene and trichloroethylene) in rats were compared with the effects of enzyme induction by phenobarbital (PB), polychlorinated biphenyl (PCB) and 3-methylcholanthrene (MC) on the metabolism of these compounds. Although causing a marked increase both in microsomal protein and cytochrome p-450 contents, PB (80 mg/kg per day for three days) and PCB (a single dose of 500 mg/kg) induced only a limited range of enzyme activity: PB increased the metabolism of toluene, styrene, chloroform, carbon tetrachloride and trichloroethylene, and PCB only increased those of toluene, styrene and trichloroethylene. MC (20 mg/kg per day for three days) had no effect on the metabolism of any of the hydrocarbons studied. In contrast, food deprivation, carbohydrate restriction and three-week ingestion of ethanol (2.0 g/day), each enhanced the metabolism of all the hydrocarbons with little or no increase in microsomal protein and cytochrome P-450 contents. PB, PCB and MC treatments enhanced the activity of enzymes involved in conjugation reactions, UDP-glucuronyltransferase and glutathione S-transferase, whereas the dietary manipulation and ethanol consumption produced no significant effect on these enzymes. It is concluded that ethanol consumption. lowered carbohydrate intake and food deprivation affect the metabolism and toxicity of volatile hydrocarbons differently from PB, PCB or MC.

Animals↗
PubMedDate not supplied

Microencapsulated organophosphorous insecticides. III. Some aspects on the volatilization of malathion and disulfoton from aqueous suspensions of microcapsules.

Comparative studies of the vaporization rate of the volatile components present in aqueous suspensions of microcapsules containing the organophosphorous insecticides S-1,2-bis (ethoxycarbonyl) ethyl-O,O-dimethyl phosphorodithioate (malathion) and O,O-diethyl S-2-ethylthioethyl phosphorodithioate (disulfoton) from inert, porous surfaces, under controlled laboratory conditions simulating natural environmental factors, were carried out. Volatilization into the atmosphere, under the given experimental conditions, was evaluated by the rate of weight loss of the microcapsule deposit and by gas chromatographic analysis of the residual insecticide on the support.

Capsules↗
PubMed1976

Insect growth regulators and in vitro volatile fatty acid production.

Three insect growth regulators were tested for their effects on in vitro volatile fatty acid production. Each material was tested at 100 and 200 ppm of feed in a triplicated trial. At the concentrations used, there was a trend toward lowered acetate:propionate ratios with inconsistent effects on total volatile fatty acid production for all materials. Of the individual acids, only the relative production of valeric was affected significantly.

Alkenes↗
PubMed1976

Synthesis of ruminal microbial protein and volatile fatty acid production in vitro.

Growth of a mixed ruminal population taken from a sheep on a protein-free (all urea) purified diet was estimated by an in vitro fermentation technique including precipitation of microbial protein by trichloracetic acid. Volatile fatty acid production in vitro was determined, and the associated a denosine triphosphate was estimated as moles volatile fatty acids X 2.4. On this basis, the quantity of microbial protein synthesized per mole of adenosine triphosphate increased at higher microbial growth rates.

Adenosine Triphosphate↗
PubMed1982

Rumen volatile fatty acid production and nutrient utilization in steers fed a diet supplemented with sodium bicarbonate and monensin.

Effects of feeding dietary supplements of monensin and sodium bicarbonate singly or in combination on production of rumen volatile fatty acids, nitrogen balance, and rumen water kinetics were studied. Four rumen fistulated steers were fed a diet (50% concentrate mix and 50% corn silage) ad libitum in a 4 X 4 Latin square design (21-day periods) with a 2 X 2 factorial arrangement of treatments. Sodium bicarbonate increased feed intake, water intake, rumen pH, fluid dilution rate, and decreased both molar proportion and production rate of propionate in the rumen. Alteration of the ratio of acetate to propionate reflects the large decrease in propionate production relative to the small increase in acetate production. In contrast, monensin did not alter significantly rumen fluid dilution rate or ruminal pH but did decrease the molar proportion of acetate and increase that of propionate. Monensin increased production of both acetate and propionate in the rumen; however, the large increase in propionate production appears to account for more of the increase in molar proportion of propionate in the rumen. Increases in total volatile fatty acid production per kilogram of dry matter consumed with monensin supplementation appears to result from decrease in feed intake, thereby increasing ruminal retention time of dry matter and potentially the extent of digestion. Efficiency of nitrogen utilization was not altered by either sodium bicarbonate or monensin.

Animals↗
PubMed1986

Volatile fatty acids in adult and young ruminants: an evaluation of a gas chromatographic method.

A gas chromatographic method was evaluated for the quantification of volatile fatty acids in blood plasma from ruminants. Amounts of .002 mg acetic acid and .001 mg of propionic and butyric acid could be quantified. Diurnal variation in acetate and propionate was found when blood samples were taken during 1 d from five cows. Jugular blood samples were taken from the five cows 8 wk before parturition to 10 wk after parturition and from three of their calves to 32 wk of age. Acetate decreased in cows at the weeks around parturition. Calves had very low acetate during the first 10 wk of life, but the concentration subsequently increased to that in adult ruminants. Propionate concentration was below .17 mM and butyrate concentration below .08 mM in all samples. It was concluded that this method was suitable for analyzing volatile fatty acids in blood plasma from ruminants, which is of importance in the study of metabolic diseases.

Acetates↗
PubMed2006

Attraction of mosquitoes to volatiles associated with blood.

Responses of the mosquitoes Aedes aegypti, Culex quinquefasciatus, and Culex nigripalpus to volatiles and compounds associated with bovine and avian blood that were presented in collagen membranes were evaluated in olfactometer and landing assays. The presence of attractants produced by blood was supported by more attraction of all species to blood than water controls in the olfactometer. Females of Ae. aegypti and Cx. quinquefasciatus were more attracted to bovine blood than to avian blood, but there was no difference in Cx. nigripalpus responses. In landing assays, significantly more females of all species landed on casings with blood than on water controls. There was no difference in landing of Ae. aegypti on bovine or avian blood. However, significantly more females of Cx. quinquefasciatus and Cx. nigripalpus landed on avian blood compared to bovine blood. Blood presented in collagen casings was an effective method for evaluating in-flight attraction and landing in all three species. In the olfactometer, several individual compounds elicited attraction in all species, but none were as attractive as blood for all species. In landing assays, several organic acids and sulfides elicited landing, with Ae. aegypti responding to the greatest number of compounds. These assay methods are effective for evaluation of volatile compounds from blood, and although responses were obtained to several compounds, none were as effective as blood in the olfactometer and landing assays.

Aedes↗
PubMed2026

Comparative Analysis of Volatile Compounds, Amino Acids, Fatty Acids, and Lipidomic Profiles in Thigh Muscles of Commercial Arbor Acres (AA) Broilers and Indigenous Chengkou and Langshan Chickens.

Flavor-related compounds and nutritional components of chicken meat vary among different breeds, but comprehensive comparisons of these characteristics between commercial and indigenous chickens remain insufficiently characterized. In this study, three chicken breeds (Arbor Acres, Chengkou, and Langshan) were slaughtered at their respective market ages, and the volatile flavor compounds, amino acids, fatty acids, and lipidomic profiles of thigh muscle were analyzed to investigate breed-associated differences in flavor-related and nutritional characteristics. Langshan chickens exhibited the highest total volatile compound content and also had the highest total amino acid levels, with significantly higher contents of umami and sweet amino acids. In addition, both indigenous breeds showed higher levels of arachidonic acid (C20:4n6) than Arbor Acres broilers, while Chengkou chickens had the highest content of docosahexaenoic acid (DHA, C22:6n3). Lipidomic analysis identified 787 lipids, with glycerophospholipids and sphingolipids as the predominant classes. Differential lipid analysis revealed that Langshan chickens had 38 upregulated lipids compared with Arbor Acres chickens, while Chengkou chickens exhibited 258 differential lipids relative to Arbor Acres chickens. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that these differential lipids were mainly associated with glycerolipid, sphingolipid, and glycerophospholipid metabolism. Correlation analysis further revealed significant associations between specific lipids and flavor-related compounds, amino acids, and fatty acids, suggesting their potential roles in breed-associated differences. Overall, this study demonstrates that indigenous chicken breeds possess distinct flavor-related and nutritional profiles compared with commercial Arbor Acres broilers and provides valuable insights into breed-associated differences in chicken meat characteristics.

amino acids↗
PubMed1998

Emission of volatile organic compounds (VOCs) from PVC floor coverings.

In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination.

Air Pollution, Indoor↗
PubMedDate not supplied

Gas chromatographic determination of volatile congeners in spirit drinks: interlaboratory study.

An interlaboratory study of a gas chromatographic (GC) method for the determination of volatile congeners in spirit drinks was conducted; 31 laboratories from 8 countries took part in the study. The method uses GC with flame ionization detection and incorporates several quality control measures which permit the choice of chromatographic system and conditions to be selected by the user. Spirit drink samples were prepared and sent to participants as 10 blind duplicate or split-level test materials for the determination of 1,1-diethoxyethane (acetal), 2-methylbutan-1-ol (active amyl alcohol), 3-methylbutan-1-ol (isoamyl alcohol), methanol (methyl alcohol), ethyl ethanoate (ethyl acetate), butan-1-ol (n-butanol), butan-2-ol (sec-butanol), 2-methylpropan-1-ol (isobutyl alcohol), propan-1-ol (n-propanol), and ethanal (acetaldehyde). The precision of the method for 9 of the 10 analytes was well within the range predicted by the Horwitz equation. The precision of the most volatile analyte, ethanal, was just above statistically predicted levels. This method is recommended for official regulatory purposes.

1-Propanol↗
PubMedDate not supplied

Multisorbent tubes for collecting volatile organic compounds in spacecraft air.

The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.

Adsorption↗
PubMedDate not supplied

[The possibility of using the data on the content of volatile fatty acids for the indirect demonstration of the causative agents of suppurative-inflammatory diseases in the pathological material].

The use of the quantitative content of volatile fatty acids as marker for the indication of the causative agents of pyo-inflammatory diseases in material taken from wounds is proposed. Thus, in 71% of cases the detection of acetic acid in a purulent wound coincided with the bacteriological isolation of monocultures, as well as associations, of facultative anaerobic bacteria. The analysis of isobutyric, butyric, isovaleric, valeric and acetic acids permitted the rapid detection of associations of obligate and facultative anaerobic bacteria in an individual patient. Changes in the quantitative content of volatile fatty acids in pathological material integrally reflected the dynamics of the causative agents of purulent infections and the effectiveness of the prescribed therapy.

Acute Disease↗
PubMedDate not supplied

[Bactericidal properties of volatile fractions of garlic phytoncids].

Changes in the bactericidal effect of volatile fractions of garlic were examined during storage. B. coli communis, Proteus vulgaris and Staph. pyogenes aureus 209 were used as test-organisms. Bactericidal properties of volatile fractions of garlic phytoncids were most pronounced prior to storage. During storage they reduced. At higher temperature (16 degrees) the decline in the bactericidal properties was much more significant than at low temperature of storage (2 degrees).

Bacillus↗
PubMed2001

Headspace/solid-phase microextraction/gas chromatography-mass spectrometry: a screening technique for the recovery and identification of volatile organic compounds (VOC's) in postmortem blood and viscera samples.

This paper describes the application of Headspace/Solid-Phase Microextraction/Gas Chromatography-Mass Spectrometry (HS/SPME/GC-MS) to the recovery and identification of volatile organic compounds in blood and viscera samples from deceased persons. The technique is used as a screening procedure to rapidly obtain information relating to toxicological investigations. The technique is suitable for the detection of volatiles (of wide boiling range) including butane, halothane, toluene, xylenes, and petrol residues in blood and viscera (lung, brain, and body fat).

Adipose Tissue↗