Carcass physical and chemical composition of three fat-tailed breeds of sheep

Physical and chemical compositions of carcasses of 73 intact ram lambs of three fat-tailed Iranian breeds; Karakul (K), Mehraban (M) and Baluchi (B) were studied. Lambs were 195 days old at slaughter. Weight of wholesale cuts and bone, fat trim and trimmed meat of each cut were recorded. Moisture, protein, ether extract and ash were determined in each of the deboned cuts. The higher (P < 0·01) proportion of leg and shoulder in K compared with those in the other two breeds was due to a smaller (P < 0·01) tail fat in the former breed. The breeds were not different for weight of wholesale cuts as percentage of tail-free carcases. Tail-free carcass of K lambs had the highest percentage of bone, protein and moisture, and those of M had the highest fat trim and the lowest bone as compared with the other breeds. The small-size Baluchi, which is well adapted to the sub-desert conditions, was the fattest of the breeds, as assessed by its highest ranking for percentage of ether extract in the carcass. On the basis of protein content, the values of M and B tail-free carcasses were 93% and 89% as high, respectively, as that for K. Differences among the breeds for the physical and chemical constituents of wholesale cuts as a percentage of the same component in half carcass without tail were small. On the basis of percentage protein, the values of shoulder, back and flap + neck were 102, 98 and 85% as high, respectively, as that for leg.     

Investigation of the role of structural domains identified in sedimentary organic matter in the sorption of hydrophobic organic compounds

The role of composition and structure of sedimentary organic matter (SOM) in the sorption of hydrophobic organic compounds (HOCs) was investigated by spiking 13C-labeled phenanthrene onto six estuarine sediments known to vary in SOM content and character. After equilibration and HF treatment, 13C NMR cross polarization and stable carbon isotope analyses indicated that the amount of desorption-resistant phenanthrene was related to aromatic carbon content. Application of the 13C NMR spectral editing technique proton spin relaxation editing (PSRE) demonstrated that all samples consisted of a rapidly relaxing and a slowly relaxing component, further evidence that SOM can be described as a structurally heterogeneous sorbent. Further, comparison of corresponding control and spiked PSRE subspectra revealed that, for each of the six sediments, desorption-resistant phenanthrene had become associated almost exclusively with the rapidly relaxing component. In only two of the sediments were there even small amounts of phenanthrene discernible in the slowly relaxing component, which is signficant as it was not always true that aromatic carbon was concentrated exclusively in the rapidly relaxing phase. The implication of these findings is that not all aromatic fractions have the same affinity for phenanthrene and that some fractions may indeed have little affinity at all. These results were interpreted as indicative that rapidly relaxing aromatic carbon associated with either sediment-associated charcoal or diagenetic organic matter plays a controlling role in the sorption of HOCs. However, the exact manner in which this rapidly relaxing aromatic phase relates to models presented elsewhere remains unclear.     

Sorption of three tetracyclines by several soils: assessing the role of pH and cation exchange

Tetracyclines (TCs) are widely used in veterinary medicine for treatment and prevention of disease and are present in animal waste products. Detection of TCs in soil, sediments, and water, and the growing concern of their potentially adverse effect on natural ecosystems have resulted in a need to understand their behavior in aqueous soil systems. TCs have multiple ionizable functional groups such that at environmentally relevant pH values, they may exist as a cation (+ 0 0), zwitterion (+ - 0), or a net negatively charged ion (+ - -), which complicates predicting their sorption, availability, and transport. We investigated the sorption of oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) by several soils varying in pH, clay amount and type, cation exchange capacity (CEC), anion exchange capacity (AEC), and soil organic carbon in 0.01 N CaCl2, 0.001 N CaCl2, and 0.01 N KCI. All three TCs are highly sorbed, especially in acidic and high clay soils. When normalized to CEC, sorption tends to decrease with increasing pH. A sorption model in which species-specific sorption coefficients normalized to pH-dependent CEC (Kd+00, kd+-0, and kd+--) and weighted by the pH-dependent fraction of each species fit the data well across all soils except for a soil rich in gibbsite and high in AEC. Resulting kd+00 values were more than an order of magnitude larger than values for either kd+0 and kd+--values such that kd+00 alone described most of the sorption observed as a function of pH for eight soils that varied in their mineralogy and pH (pH ranged from 4 to 8).     

Sorption to black carbon of organic compounds with varying polarity and planarity

It is becoming increasingly clear that the products of incomplete combustion (soot and charcoal, collectively termed black carbon or BC) can be responsible for as much as 80 - 90% of the total sorption to sediments of aromatic, planar, and hydrophobic compounds such as polycyclic aromatic hydrocarbons or planar polychlorinated biphenyls. In the present study, it was investigated whether a nonpolar aliphatic compound (hexachloroethane) and three nonplanar bipolar compounds with different functional groups [free electron pairs but no aromatic ring (butylate) or free electron pairs and an aromatic ring (diuron, atrazine)] would also show strong and nonlinear sorption to a BC-enriched sediment. At a concentration of 1 ng/L, the extent of elevated BC sorption compared to total organic carbon (TOC) sorption increased in the order atrazine < hexachloroethane < butylate < diuron. Rationalization of the differences between the sorbates was attempted in terms of dispersive and steric effects. This study shows that the effects of strong BC sorption apply to a broader range of organic contaminants than previously thought, and the results will aid in a better understanding of BC sorption mechanisms and improved fate modeling of contaminants in the environment.     

Sorption of polar and nonpolar aromatic organic contaminants by plant cuticular materials: role of polarity and accessibility

In both forest and agricultural soils, plant derived cuticular materials can constitute a significant part of soil organic matter. In this study, the sorption of nonpolar (naphthalene and phenanthrene) and polar (phenol and 1-naphthol) aromatic organic pollutants to aliphatic-rich cuticularfractions of green pepper (Capsicum annuum) (i.e., bulk (PC1), dewaxed (PC2), nonsaponifiable (PC3), nonsaponifiable-nonhydrolyzable (PC4), and dewaxed-hydrolyzed residue (PC5)) were examined to better understand the influence of polarity and accessibility on their sorption behavior. The polarity and structures of cuticular fractions were characterized by elemental analysis, Fourier transform infrared spectroscopy, and solid-state 13C NMR. The sorption isotherms fit well to the Freundlich equation. Sorption of the tested organic compounds to PC4, which had more condensed domains, was nonlinear (Freundlich N(s) values of 0.766-0.966). For naphthalene and phenanthrene, the largest sorption capacity (K(oc)) occurred in PC5, which contained the highest paraffinic carbons (63%) and the lowest polarity: approximately 2 and aproximately 3 times higher than the respective carbon-normalized octanol-water partition coefficient (K(owc)), indicating that PC5 was a powerful sorption medium. For phenol and 1-naphthol, the largest K(oc) values occurred in PC4 with polar aromatic cores: approximattely 17 and approximately 7 times higher than the respective K(owc), suggesting that PC4 was much more accessible and compatible to polar aromatic pollutants than nonpolar aromatic pollutants. There was little or no correlation of K(oc) with either aliphatic or aromatic components of the tested aliphatic-rich sorbents because the polarity and accessibility apparently played a regulating role in the sorption of organic contaminants.     

Sorption of heterocyclic organic compounds to reference soils: column studies for process identification

In this study, the sorption behavior of a wide variety of N-, S-, and O-heterocyclic compounds (NSOs) to reference soils (Eurosoils 1-5) was characterized by a soil column chromatography (SCC) approach. The major goal was to identify the compound specific and environmental factors influencing sorption processes. The sorption of S- and O-heterocyclic compounds (thiophene, benzothiophene, 5-methylbenzo[b]thiophene, benzofuran, 2-methylbenzofuran, and 2,3-dimethylbenzofuran) was generally controlled by nonspecific interactions with soil organic carbon (OC). With regard to non-ionizable N-heterocyclic compounds, pyrrole, 1-methylpyrrole, and pyrimidine were hardly retarded in any soil. The sorption of indole, 2-hydroxyquinoline, and benzotriazole was dominated by specific interaction (e.g., complexation of surface-bound cations) rather than partition to soil OC. The sorption of ionizable N-heterocyclic compounds (quinoline, isoquinoline, quinaldine, 2-methylpyridine, and pyridine) can be described by a conceptual model including partitioning to soil OC, cation exchange, and an additional sorption process (probably surface complexation of the neutral species). Cation exchange was usually the dominant mechanism in the sorption of ionizable compounds if the protonated fraction of the compound exceeded 5%. Otherwise, surface complexation became dominant. Soil pH was the most important factor influencing the sorption of ionizable NSOs. Our study suggests that a fairly precise assessment of sorption in most soils can be expected for N-, S-, and O-heterocyclic compounds if the three sorption mechanisms are taken into accountwhere appropriate. Deviations from this behavior indicated special cases where additional soil specific properties (e.g., accessible surface, CEC, charge density) need to be considered such as for 2-methylpyridine and pyridine sorption to Eurosoil 1.     

Sorption of organic contaminants by carbon nanotubes: influence of adsorbed organic matter

Sorption of three types of dissolved organic matter (DOM; i.e., humic acid, peptone and alpha-phenylalanine) by a mutiwalled carbon nanotube (MWNT40) and sorption of phenanthrene (Phen), naphthalene (Naph), and 1-naphthol (1-Naph) by the original and DOM-coated MWNT40 were examined. Sorption data of Phen, Naph, and 1-Naph by all sorbents were fitted with Freundlich and Polanyi models. MWNT40 had nonlinear isotherms for all DOMs examined. Sorption of DOMs by MWNT40 followed the order peptone > humic acid > alpha-phenylalanine. The humic acid used in this study had much lower sorption for Phen, Naph, and 1-Naph than MWNT40, but its coating did not make striking changes on sorption of these compounds by MWNT40, suggesting that humic acid coating dramatically altered the physical form and surface properties of MWNT40. Peptone coating made the strongest suppression on sorption of Phen, Naph, and 1-Naph by MWNT40 among the three DOMs used, due to its highest sorption on MWNT40, thus causing a great reduction in accessibility of sorption sites. Polanyi modeling results showed that reduction in the maximum volume sorption capacity (Q0) of MWNT40 induced by DOM coating followed the order Phen < Naph < 1-Naph. 1-Naph was less hydrophobic than Phen and Naph but it had much higher sorbed volume (V(m)) than Phen and Naph at individual RT In(S(w)/C(e))/V(s)points for all sorbents. The correlation curve for the Polanyi model was applicable for sorption of aromatic compounds of similar structure by the original and DOM-coated carbon nanotubes.     

Biosorption of nonpolar hydrophobic organic compounds to Escherichia coli facilitated by metal and proton surface binding

We observed that the presence of transition metal ion, Ag+, Cu2+, or Fe3+, at a concentration of 3 mg L(-1) increases sorption of two nonpolar hydrophobic organic compounds (HOCs), phenanthrene (PHEN), and 1,2,4,5-tetrachlorobenzene (TeCB) by 1.5-4 times to Gram-negative bacteria Escherichia coli. Complexation of transition metals with the deprotonated functional groups (mainly carboxyl) of bacterial cell walls neutralizes the negative charge, making the bacterial surface less hydrophilic and enhancing hydrophobic partition of HOCs. This is evidenced by the fact that the zeta potential (zeta) value of bacteria becomes less negative when a transition metal is present. Furthermore, the observed higher sorption of PHEN than TeCB at low pH (3.8) cannot be fully explained by the pH-dependent hydrophobic effects. The results led us to propose two specific sorption mechanisms for pi-donor compounds: cation-pi interactions with protonated amines and pi H-bonding with protonated carboxyls. The biosorption of PHEN was best described as pi-donor compared to the biosorption of TeCB considered non-pi-donor. Results of the present study highlight that the presence of coexisting transition metals and changes on pH have a major effect on the biosorption of nonpolar HOCs.     

Sorption of lipophilic organic compounds to wood and implications for their environmental fate

The sorption from water to wood (KWood) of 10 organic chemicals (log KOW, 1.48-6.20) was experimentally determined for oak (Quercus robur) and basket willow (Salix viminalis). Linear regression yielded log KWood = -0.27 (+/- 0.25) + 0.632 (+/- 0.063) log KOW for oak (r = 0.90, n = 27) and log KWood = -0.28 (+/- 0.40) + 0.668 (+/- 0.103) log KOW for willow (r = 0.79, n = 27). According to an equilibrium-partitioning model, wood should be an important storage compartment for lipophilic environmental chemicals, but this is contrary to analytical results. Diffusive uptake from air into wood was estimated to be a relevant transport process only for chemicals with a high KAW. Uptake of chemicals from soil via xylem into stem was simulated with a dynamic one-compartment model. This pathway seems to be important for chemicals with low and intermediate lipophilicity. In large trees, the chemicals are retained for a long time. If metabolism inside the stem occurs, wood can serve as a "safe sink" for environmental chemicals. This might be of use in phytoremediation.     

Hydrophilic and hydrophobic sorption of organic acids by variable charge soils: effect of chemical acidity and acidic functional group

Sorption of organic acids by variable-charge soil occurs through both hydrophilic and hydrophobic sorption. In this study, the effect of chemical acidity and the type of acidic functional group on the relative contribution of hydrophilic and hydrophobic processes to sorption by a gibbsite-dominated and a kaolinite-dominated variable-charge soils was quantified by measuring sorption isotherms from different electrolytes (CaCl2, Ca(H2PO4)2, and KCl). The A1 soil is dominated by gibbsite whereas the DRC soil is primarily kaolinite. The organic acids investigated include five chlorinated phenols (pentachlorophenol, 2,3,4,6-tetrachlorophenol, 2,4,6-trichlorophenol, 2,4,5-trichlorophenol, and 2,4-dichlorophenol) with pKa values ranging from 4.69 to 7.85 and two acidic herbicides (2,4-D (pKa = 2.8) and prosulfuron (pKa = 3.76)) that contain carboxyl and urea functional groups, respectively. Anion exchange of chlorinated phenols and prosulfuron on both variable-charge soils as well as 2,4-D sorption on the A1 soil was linearly correlated to chemical acidity. The effective positive surface charge [AEC/(AEC + CEC)] and the anionic fraction of the organic acid in solution, which are both pH-dependent, were sufficient to estimate the contribution of anion exchange to organic acid sorption except for 2,4-D sorption by DRC soil. The latter was much greater than would be predicted from the pKa of 2,4-D. Calcium bridging between silanol edge group and 2,4-D was hypothesized and corroborated by differences in sorption measured from KCl and CaCl2 solutions. For predicting contributions from hydrophobic processes, a log-log linear relationship between pH-dependent octanol-water (Kow(pH)) and organic carbon-normalized sorption coefficients (Koc(pH)) appeared adequate.     

Sorption of organic compounds to fresh and field-aged activated carbons in soils and sediments

Activated carbon (AC) amendment to polluted sediment or soil is an emerging in situ treatment technique that reduces freely dissolved porewater concentrations and subsequently reduces the ecological and human health risk of hydrophobic organic compounds (HOCs). An important question is the capacity of the amended AC after prolonged exposure in the field. To address this issue, sorption of freshly spiked and native HOCs to AC aged under natural field conditions and fresh AC amendments was compared for one soil and two sediments. After 12-32 months of field aging, all AC amendments demonstrated effectiveness for reducing pore water concentrations of both native (30-95%) and spiked (10-90%) HOCs compared to unamended sediment or soil. Values of K(AC) for field-aged AC were lower than freshly added AC for spiked HOCs up to a factor of 10, while the effect was less for native HOCs. The different behavior in sorbing native HOCs compared to freshly spiked HOCs was attributed to differences in the sorption kinetics and degree of competition for sorption sites between the contaminants and pore-clogging natural organic matter. The implications of these findings are that amended AC can still be effective in sorbing additional HOCs some years following amendment in the field. Thus, a certain level of long-term sustainability of this remediation approach is observed, but conclusions for decade-long periods cannot be drawn solely based on the present study.     

Sorption of very hydrophobic organic compounds (VHOCs) on dissolved humic organic matter (DOM). 2. Measurement of sorption and application of a Flory-Huggins concept to interpret the data

Sorption phenomena of very hydrophobic compounds (VHOCs, log K(OW) > 5) on dissolved humic organic matter (DOM) are overwhelmingly based on partitioning processes. In this respect, DOM is very similar to "rubbery" soil/sediment OM. To exclude system adsorption effects, the DOM sorption coefficients (K(DOM)) of VHOCs were determined using a dynamic approach based on the VHOCs' aqueous solubility enhancement in the presence of DOM. Partition coefficients are strongly correlated to the analytes' Kow across the alkane, PAH, and PCB groups under study. These three "families" are regarded to be good models of hydrophobic partitioning. On the basis of a uniform one-parameter concept characterizing sorption on amorphous polymers, Hildebrand solubility parameters of amorphous polymeric sorbents, including DOM, and of sorbates can be calculated on the basis of partition coefficients. Likewise, partition coefficients can be estimated using Hildebrand solubility parameters. Literature-based partition coefficients on DOM fit very well in this universal one-parameter concept. On using our own sorption data of PAHs, PCBs, and alkanes on DOM, an almost identical solubility parameter for the DOM polymer under study is obtained. The concept is also very useful in understanding both waterborne and airborne bioconcentration processes, which are considered to be partitioning phenomena.     

Characterization of traditional Istrian dry-cured ham by means of physical and chemical analyses and volatile compounds

The aroma-active compounds of Istrian dry-cured ham were investigated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics: moisture, protein, fat, ash and NaCl content, a(w) value; colour: L*, a*, b* and oxidation of fat: TBARS test. About 50 volatile compounds were identified and quantified which belonged to several classes of chemical: 5 alcohols, 8 aldehydes, 7 alkanes, 1 ketone, 2 esters, 9 monoterpenes and 15 sesquiterpenes. Except volatile compounds derived from lipolysis and proteolysis the most abundant constituents were terpenes (62.97; 41.43%) that originate from spices added in the salting phase of the production process.     

Changes during heating in chemical composition and in-vitro digestion of four commodities

The effects of duration of heating on the composition and digestibility of whole cotton seed, almond hulls, whole pressed safflower seed and alfalfa were studied. The four commodities were heated at 125°C from 0 to 120 h. Nitrogen and ash values were relatively stable across commodities and heating times. However, acid detergent fibre, neutral detergent fibre, in-vitro neutral detergent fibre remaining after 48 h fermentation and acid detergent insoluble nitrogen increased hyperbolically, approaching a relatively constant value at long heating times for all commodities. The sensitivity of each commodity to heat damage was different, and the rate that each analysis value approached a relatively constant value differed across commodities. In general, alfalfa was the most sensitive and whole cotton seed the least sensitive for a given nutrient change with heating time. Also the amount of neutral detergent fibre digested approached a relatively constant value at longer heating times for whole cotton seed, whole pressed safflower seed and alfalfa while approaching zero for almond hulls. Prior analysis of an unheated commodity is necessary to utilise compositional analyses to determine heat damage.     

Farm and factory production of goat cheese whey results in distinct chemical composition

To analyze differences in fat and protein content in cheese whey (CW) manufactured in cheese-making factories and farms, goat CW samples were obtained from 60 cheese-making farms and 20 cheese factories. Gross composition of samples was analyzed by using an MIRIS device (MIRIS Inc., Uppsala, Sweden), whey protein composition was subjected to electrophoretic analysis, and fatty acid composition was analyzed via gas chromatography. Goat CW from farms contained higher dry matter content (70.6 vs. 50.8 g/L, farms vs. cheese factories, respectively) and a higher fat percentage (10.5 vs. 1.2% over dry matter, farms vs. cheese factories, respectively) than CW from cheese factories. Analysis of individual proteins showed that CW from farms contained higher concentrations of lactoferrin (0.4 vs. 0.2 mg/mL of CW, farms vs. cheese factories, respectively) and caprine serum albumin (0.6 vs. 0.4 mg/mL of whey, farms vs. cheese factories, respectively) than CW from cheese factories. No differences were observed in the fatty acid profile. The main fatty acids present in goat CW were C16:0, C18:1, C14:0, and C18:0. Thus, the origin of CW affects gross composition and the protein profile, but not the fatty acid profile.