Volatile fatty acids (C2-C7) analysis in wool scouring water and lanolin is presented. These substances are of major interest as malodorous compounds in urban and industrial wastewaters. In this work, they have been analysed in wool scouring water by headspace solid-phase microextraction followed by gas chromatography negative chemical ionisation mass ...

Patulin, a toxic fungal metabolite, negatively affects rumen fermentation. This mycotoxin has also been associated with intoxication cases in cattle. This study investigates the use of SH-containing reducing compounds to prevent patulin's negative effects on the rumen microbial ecosystem. The effect of 50 microg/mL patulin on the fermentation of alfalfa ...

Eight Holstein steers with cannulas in the rumen and proximal duodenum were used in a split-plot design experiment to evaluate the interaction of body weight (175 vs. 370 kg) and level of fat supplementation (0, 3, 6, and 9% yellow grease) on characteristics of digestion and feeding value of fat ...

Five lactating dairy cows with a permanent cannula in the rumen were given (kg DM/d) a normal diet (7.8 concentrates, 5.1 hay) or a low-roughage (LR) diet (11.5 concentrates, 1.2 hay) in two meals daily in a two-period crossover design. Milk fat (g/kg) was severely reduced on diet LR. To ...

In the relatively pristine ecosystem in Kejimkujik Park, Nova Scotia, methylmercury (MeHg) concentrations in loons, Gavia immer, are among the highest recorded anywhere in the world. This study investigated the influence of bedrock lithology on MeHg concentrations in wetlands. Twenty-five different wetland field sites were sampled over four different bedrock ...

Volatiles of rhubarb (Rheum rhabarbarum L.) stalks were isolated by means of vacuum headspace method and analyzed by capillary gas chromatography-mass spectrometry. Fifty-nine components were reported for the first time in rhubarb. A striking feature of the extracts obtained is the preponderance (approximately 65%) of compounds with C(6) skeletons. In ...

Flor yeast Saccharomyces cerevisiae (capensis G1) strain assimilates gluconic acid during the aerobic biological aging process of sherry wines and exerts significant changes on the final volatile compounds of wines, especially a decrease in volatile acidity and butanoic, isobutanoic, 2-methylbutanoic, and 3-methylbutanoic acids. This decrease may have a favorable effect ...

We tested the chemotactic responses of dauer juvenile stages (DJs) of the insect parasitic nematode Heterorhabditis bacteriophora to a variety of compounds that are known to be highly attractive or highly repellent to Caenorhabditis elegans. While H. bacteriophora DJs respond to alcohols and some aromatic compounds as well as to ...

In France, fatty residues considered as "non-ultimate" waste will not be accepted in landfill from 2002, in accordance with French legislation. Anaerobic digestion appears as an alternative process to mobilize and profitably use such fermentable waste. In this work, the effect of an alkaline pretreatment on the degradation of hexane ...

Operating anaerobic reactors at high organic loading rates during start-up can lead to instability, accumulation of volatile fatty acids and low pH, such problems being exacerbated in reactors that exhibit plug-flow characteristics. Moreover, plug-flow conditions increase the exposure of biomass to any toxic components in the feed. To overcome these ...

Estimating the stability of microbial community structures may be useful in advanced biological wastewater treatment system design and operation. In this research, a monitoring method using fatty acid profiles was evaluated for detecting changes in microbial community structures. For the evaluation, the operating parameters such as pH, organic loading, and ...

Batch cultures of mixed rumen micro-organisms were used to study the effects of different concentrations of disodium fumarate on the fermentation of five concentrate feeds (maize, barley, wheat, sorghum and cassava meal). Rumen contents were collected from four Merino sheep fed lucerne hay ad libitum and supplemented with 300 g ...

Natural (raw) and roasted hazelnuts were compared for their differences in volatile components and sensory responses. A total of 79 compounds were detected in both hazelnuts, of which 39 (27 positive, 5 tentative, and 7 unknown) were detected in natural hazelnut and 71 (40 positive, 14 tentative, and 17 unknown) ...

Two experiments were conducted to investigate the basis for higher voluntary intakes and increased alpha-linolenic acid content in milk from cows offered clover silages. Six cows with rumen and duodenal cannulae were used in a four-period changeover-design experiment. Cows received 8 kg/d of dairy concentrate and had ad libitum access ...

2-Hydroxy-4-(methylthio) butanoic acid (HMB) positively affects milk composition and yield, potentially through ruminal actions. Four continuous culture fermenters were used to determine the optimal concentration of HMB for digestibility of organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and hemicellulose and synthesis of microbial N. A highly ...

A complex and fast dynamic response of the anaerobic biogas system was observed when the system was subjected to pulses of volatile fatty acids (VFAs). It was shown that a pulse of specific VFAs into a well-functioning continuous stirred tank reactor (CSTR) system operating on cow manure affected both CH(4) ...

Plants respond to insect herbivory by emitting volatile compounds that attract natural enemies of the herbivores. Biosynthesis of many of these volatiles in plants is induced by herbivore-produced compounds. Components of tobacco hornworm (THW) regurgitant were investigated for their efficacy as elicitors of corn seedling volatiles. Two components that elicited ...

Four prepubertal Holstein heifers, average age 184 +/- 2.1 d and 169.1 +/- 15.8 kg of body weight, fitted with rumen cannulae were used to evaluate effects of altering the soluble CP and potentially rumen degradable protein fractions of diets containing 16% CP and 71.5% TDN. Parameters studied included rumen ...

The quantitative distribution of volatile compounds in the pulp, cloud, and serum of a freshly squeezed orange juice (cv. Naveline) was measured. Juice monoterpene and sesquiterpene hydrocarbons were primarily recovered from the pulp (74.0 and 87.2%, respectively) and cloud (7.3 and 14.9%, respectively). Esters and monoterpene alcohols were mainly found ...

Volatile components from fresh and air-dried leaf-buds of Populus nigra L. (Salicaceae) were isolated by Likens-Nickerson apparatus and analyzed using GC/MS. Forty-eight components (ca. 95% of the total isolate) were identified among black poplar bud volatiles. Sesquiterpene alcohols beta-eudesmol and alpha-eudesmol represented 26.3-28.7% of the oil. Other major sesquiterpene compounds ...

Digestion and portal net flux of nutrients were studied in sheep fed twice daily with fresh orchard-grass. Digestive flows were measured in six fistulated sheep using the double-marker technique. Three sheep were fitted with catheters and blood-flow probes, allowing nutrient net flux measurements across the portal-drained viscera (PDV), the mesenteric-drained ...

In order to test the suitability of the horse as a nutritional model for elephants, digestibility studies were performed with six captive Asian elephants on six different dietary regimes, using the double marker method with acid detergent lignin as an internal and chromium oxide as an external digestibility marker. Elephants ...

Anaerobic digestion of animal manure, sewage and other agricultural wastes at psychrophilic temperatures has not been explored as extensively as either mesophilic or thermophilic digestion, probably due to little anticipation of the development of economically attractive systems using this technology. This review article discusses psychrophilic anaerobic digestion studies reported by ...

This paper reports on the composition of aroma compounds and fatty acids and some physico-chemical parameters (juice percentage, acidity and total sugars) in five varieties of citrus: blood orange, sweet orange, lemon, bergamot and bitter orange. Volatile compounds and methyl esters have been analyzed by gas chromatography. Limonene is the ...

The anaerobic bioconversion of solid poultry slaughterhouse wastes was kinetically investigated. The modified version of <METHANE> simulation model was applied for description of experimental data in mesophilic laboratory digester and assays. Additionally, stages of formation and consumption of long chain fatty acids (LCFA) were included in the model. Batch data ...

Tropical livestock is often maintained on roughage-based diets deficient in N, and therefore requires supplementation with protein-rich substrates to achieve reasonable production levels. The optimum inclusion rate of a potential supplement is usually determined by in vivo feeding trials or by in vitro incubation of the diet components to estimate ...

Ophrys flowers mimic virgin females of their pollinators, and thereby attract males for pollination. Stimulated by scent, the males attempt to copulate with flower labella and thereby ensure pollination. Here, we show for the first time, to our knowledge, that pollinator attraction in sexually deceptive orchids may be based on ...

In the City of Karlsruhe/Germany anaerobic digestion of 7200 ta(-1) of separately collected biowaste has proven its feasibility at an organic loading rate (OLR) of up to 8.5 kg CODm(-3)d(-1). An extension of biowaste collection over the whole city area would increase the amount of biowaste to 12,000 ta(-1), leading ...

Characterization of the aromatic profile in commercial guava essence and fresh fruit puree by GC-MS yielded a total of 51 components quantified. Commercial essence was characterized to present a volatile profile rich in components with low molecular weight, especially alcohols, esters, and aldehydes, whereas in the fresh fruit puree terpenic ...

Cashew apple nectar is a secondary product from the production of cashew nuts and possesses an exotic tropical aroma. Aroma volatiles in pasteurized and reconstituted (from concentrate) Brazilian cashew apple nectars were determined using GC-MS and split, time-intensity GC-olfactometry (GC-O)/GC-FID. Methional, (Z)-1,5-octadien-3-one, (Z)-2-nonenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, beta-damascenone, and delta-decalactone were identified ...

Batch cultures of mixed rumen micro-organisms were used to study the effects of different concentrations of malate (Rumalato(R); Norel & Nature S.A., Barcelona, Spain; composed of disodium malate-calcium malate (0.16:0.84, w/w)) on the fermentation of four cereal grains (maize, barley, wheat and sorghum). Rumen contents were collected from four Merino ...

The columnar cactus Cereus peruvianus (L.) Miller, Cactaceae (koubo), is grown commercially in Israel. The unripe fruits are green, and the color changes to violet and then to red when the fruit is fully ripe. The content of soluble sugars was found to increase 5-fold during ripening. Glucose and fructose ...

The influence of propionate supplementation on the splanchnic metabolism of energy-yielding nutrients and the supply of glucose to the hindlimb was investigated in growing lambs. Six rumen-cannulated and multicatheterized lambs (32.2 kg), fed frozen rye grass at 690 kJ metabolizable energy intake/d per kg body weight0.75, were infused intraruminally with ...

The accumulation of volatile fatty acids such as acetic acid can cause reactor pH problems and the inhibition of microorganisms utilised in anaerobic digestion processes. A cross-flow membrane process using Teflon and ion-exchange membranes was investigated as a means of separating acetic acid from pure acetic acid solution and rumen ...

The effect of nisin (in the form of Nisaplin) was determined using two species of rumen ciliate protozoa in vitro, on their co-culture bacterial population, and volatile fatty acid concentration. Nisaplin did not affect the in vitro growth of Entodinium caudatum at concentrations of 50-400 mg/L during short-term treatment (5 ...

AIMS: To identify the most effective mixture of non-esterified lauric (C12) and myristic (C14) acid in suppressing ruminal methanogenesis, and to investigate their effects on the methanogenic population. METHODS AND RESULTS: C12/C14 mixtures were incubated with rumen fluid using the Hohenheim gas test apparatus. Methane production and the numbers of ...

In this work several feed-forward back-propagation neural networks (FFBP) were trained in order to model, and subsequently control, methane production in anaerobic digesters. To produce data for the training of the neural nets, four anaerobic continuous stirred tank reactors (CSTR) were operated in steady-state conditions at organic loading rates (Br) ...

In vitro experiments were conducted to examine the degradation of d- and l-isomers of tryptophan (Trp) and 10 related indolic compounds by mixed rumen bacteria (B), protozoa (P) and a combination of the two (BP). The analyses were carried out by HPLC. d-Trp (1.0 mM) was not degraded by rumen ...

Volatile and nonvolatile compounds present in the water-soluble fraction (WSF) and water-soluble fraction with molecular weight lower than 1000 Da (WSF < 1000 Da) of six Spanish cheeses, Cabrales, Idiazábal, Mahón, Manchego, Roncal, and a goat's milk cheese, were analyzed. Different nitrogen fractions (determined by Kjeldahl method), caseins (by capillary ...

Rosa chinensis var. spontanea predominantly emits 1,3,5-trimethoxybenzene together with methyleugenol and isomethyleugenol as minor floral scent compounds. Two O-methyltransferases (OMTs), designated as RcOMT1 and RcOMT2, were isolated from rose flower petals using homology-based screening strategies. RcOMT1 efficiently methylated eugenol and isoeugenol to yield volatile methyleugenol and isomethyleugenol, respectively. Furthermore, the ...

The pretreatment of corn stover with H2SO4 and H3PO4 was investigated. Pretreatments were carried out from 30 to 120 min in a batch reactor at 121 degrees C, with acid concentrations ranging from 0 to 2% (w/v) at a solid concentration of 5% (w/v). Pretreated corn stover was washed with ...

Accumulation of substrate onto the biomass was quantified under steady-state and shock conditions in a fixed bed reactor fed with an oleic acid-based synthetic effluent. The accumulation of substrate onto the sludge was more dependent on oleic acid concentration than on oleic acid loading rate and decreased the acetogenic, acetoclastic ...

Morphological changes in anaerobic granular sludge fed with increasing loads of oleic acid were quantified by image analysis. The combination of this technique with data on the accumulation of adsorbed long chain fatty acid and with the molecular characterization of microbial community gave insight into the mechanisms of sludge disintegration, ...

The process of anaerobic digestion is highly influenced by the environmental and operational factors like organic acids concentration and the reactor volume occupied by the feed material. The optimum level of organic acids is commonly assumed to be in the range between 2,500 and 3,500 mg/l for the anaerobic digestion ...

Large releases of 1-penten-3-ol (pentenol) and 1-penten-3-one (pentenone) were recently observed from a variety of leaves subjected to freeze-thaw damage in the presence of oxygen. In order to understand the biochemical origins of these volatiles, soybean leaf extracts were used to determine if the formation of pentenol and pentenone can ...

During the maturation of snake fruit (Salacca edulis Reinw) Pondoh, the contents of sucrose, glucose, fructose, and volatile compounds changed drastically. The glucose, fructose, and volatile compounds contents showed their maximum levels at the end of maturation; however, the sucrose content decreased. During maturation, the flesh firmness tended to increase; ...

Variations of fatty acid compositions, glycosides precursors, and lipoxygenase and glycosidase enzymatic activities were used simultaneously to differentiate for nine genetically different cultivated teas, four seasonal changes, and the affect of leaf maturity. The muscatel flavor of second-flush teas was associated with increased activities of glycosidase and several terpenes, phenolics, ...

The aim of this work was to characterize the volatile fractions of two Brazilian honeys known as caju and marmeleiro. The volatile components were isolated by a column extraction technique using acetone as the extraction solvent. Totals of 59 and 36 volatile compounds were definitely or tentatively identified in the ...

The volatiles released from elicitor (copper chloride, jasmonic acid, UV, L-methionine and chitosan oligomer)-treated and rice blast fungus-inoculated rice leaves were collected by the solid-phase microextraction technique and analyzed by GC-MS. (Z)-3-Hexen-1-ol, monoterpenes, methyl salicylate, and sesquiterpenes were identified as elicitor-induced volatiles by a comparison of their GC retention times ...

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16 h in three bulls with large rumen cannulas. The intestinal disappearance of ...