Simulating the effects of grassland management and grass ensiling on methane emission from lactating cows

A dynamic, mechanistic model of enteric fermentation was used to investigate the effect of type and quality of grass forage, dry matter intake (DMI) and proportion of concentrates in dietary dry matter (DM) on variation in methane (CH(4)) emission from enteric fermentation in dairy cows. The model represents substrate degradation and microbial fermentation processes in rumen and hindgut and, in particular, the effects of type of substrate fermented and of pH oil the production of individual volatile fatty acids and CH, as end-products of fermentation. Effects of type and quality of fresh and ensiled grass were evaluated by distinguishing two N fertilization rates of grassland and two stages of grass maturity. Simulation results indicated a strong impact of the amount and type of grass consumed oil CH(4) emission, with a maximum difference (across all forage types and all levels of DM 1) of 49 and 77% in g CH(4)/kg fat and protein corrected milk (FCM) for diets with a proportion of concentrates in dietary DM of 0.1 and 0.4, respectively (values ranging from 10.2 to 19.5 g CH(4)/kg FCM). The lowest emission was established for early Cut, high fertilized grass silage (GS) and high fertilized grass herbage (GH). The highest emission was found for late cut, low-fertilized GS. The N fertilization rate had the largest impact, followed by stage of grass maturity at harvesting and by the distinction between GH and GS. Emission expressed in g CH(4)/kg FCM declined oil average 14% with an increase of DMI from 14 to 18 kg/day for grass forage diets with a proportion of concentrates of 0.1, and on average 29% with an increase of DMI from 14 to 23 kg/day for diets with a proportion of concentrates of 0.4. Simulation results indicated that a high proportion of concentrates in dietary DM may lead to a further reduction of CH, emission per kg FCM mainly as a result of a higher DM I and milk yield, in comparison to low concentrate diets. Simulation results were evaluated against independent data obtained at three different laboratories in indirect calorimetry trials with COWS consuming GH mainly. The model predicted the average of observed values reasonably, but systematic deviations remained between individual laboratories and root mean squared prediction error was a proportion of 0.12 of the observed mean. Both observed and predicted emission expressed in g CH(4)/kg DM intake decreased upon an increase in dietary N:organic matter (OM) ratio. The model reproduced reasonably well the variation in measured CH, emission in cattle sheds oil Dutch dairy farms and indicated that oil average a fraction of 0.28 of the total emissions must have originated from manure under these circumstances.

Provenance of the oil in par-fried french fries after finish frying

Frozen par-fried French fries are finish-fried either by using the same type of oil used for par frying, or a different type. The nutritive quality of the final oil contained in the product depends on the relative amounts and the fatty acid (FA) composition of the oils used for par frying and finish frying. With the aim of understanding the provenance of the oil in the final product, par-fried French fries—either purchased ready or prepared in the laboratory—were finish fried in oils different from the ones used for par frying. The moisture content, oil content, and FA compositions of the par-fried and finish-fried products were experimentally determined, and the relative amounts of each of the oils present in the final product were calculated using the FAs as markers and undertaking a mass balance on each component FA. The results demonstrate that 89% to 93% of the total oil in the final product originates from the finish-frying step. The study also shows that a significant proportion of the oil absorbed during par frying is expelled from the product during finish frying. Further, the expulsion of par-frying oil was found to occur in the early stages of the finish-frying step. Experiments involving different combinations of par-frying and finish-frying oils showed that the relative proportions of the 2 oils did not depend on the individual fatty acid profiles. This study concludes that any positive health benefits of using an oil having a favorable FA profile for par frying, can potentially be lost, if the oil used for finish frying has a less favorable composition.

The impact of blanching and high-pressure pretreatments on oil uptake of fried potato slices

The effect of high-pressure (HP) pretreatment on oil uptake of potato slices is examined in this paper. Potato slices were treated either by HP or thermal blanching, or a combination of thermal blanching followed by HP prior to frying. The effect of HP on starch gelatinization and potato microstructure was assessed by differential scanning calorimeter and environmental scanning electron microscope (ESEM), respectively. After treatments, the slices were fried in sunflower oil at 185 °C for a predetermined time. Frying time was either kept constant (4 min) or varied according to the time needed to reach a desired moisture content of ≈2%. The high pressure applied in this study was found not to be sufficient to cause a significant degree of starch gelatinization. Analysis of the ESEM images showed that blanching had a limited effect on cell wall integrity. HP pretreatment was found to increase the oil uptake marginally. When frying for a fixed time, the highest total oil content was found in slices treated at 200 MPa for 5 min. The oil content was found to increase significantly (p<0.05) to 41.23±1.82 compared to 29.03±0.21 in the control slices. The same effect of pressure on oil content was found when the time of frying varied. On the other hand, HP pretreatment was found to decrease the frying time required to achieve a given moisture content. Thus, high-pressure pretreatment may be used to reduce the frying time, but not oil uptake.

Potential anti-cancer effects of virgin olive oil phenols on colorectal carcinogenesis models in vitro

The traditional Mediterranean diet is thought to represent a healthy lifestyle; especially given the incidence of several cancers including colorectal cancer is lower in Mediterranean countries compared to Northern Europe. Olive oil, a central component of the Mediterranean diet, is believed to beneficially affect numerous biological processes. We used phenols extracted from virgin olive oil on a series of in vitro systems that model important stages of colon carcinogenesis. The effect the extract on DNA damage induced by hydrogen peroxide was measured in HT29 cells using single cell microgel-electrophoresis. A significant anti-genotoxic linear trend (p=0.011) was observed when HT29 cells were pre-incubated with olive oil phenols (0, 5, 10, 25, 50, 75, 100 microg/ml) for 24 hr, then challenged with hydrogen peroxide. The olive oil phenols (50, 100 microg/ml) significantly (p=0.004, p=0.002) improved barrier function of CACO2 cells after 48 hr as measured by trans-epithelial resistance. Significant inhibition of HT115 invasion (p<0.01) was observed at olive oil phenols concentrations of 25, 50, 75, 100 microg/ml using the matrigel invasion assay. No effect was observed on HT115 viability over the concentration range 0, 25, 50 75, 100 microg/ml after 24 hr, although 75 and 100 microg/ml olive oil phenols significantly inhibited HT115 cell attachment (p=0.011, p=0.006). Olive oil phenols had no significant effect on metastasis-related gene expression in HT115 cells. We have demonstrated that phenols extracted from virgin olive oil are capable of inhibiting several stages in colon carcinogenesis in vitro.

Combined action of S-carvone and mild heat treatment on Listeria monocytogenes Scott A

The combined action of the plant-derived volatile, S-carvone, and mild heat treatment on the food-borne pathogen, Listeria monocytogenes, was evaluated. The viability of exponential phase cultures grown at 8 °C could be reduced by 1·3 log units after exposure to S-carvone (5 mmol l−1) for 30 min at 45 °C, while individual treatment with S-carvone or exposure to 45 °C for 30 min did not result in a loss in viability. Other plant-derived volatiles, namely carvacrol, cinnamaldehyde, thymol and decanal, were also found to reduce the viability of L. monocytogenes in combination with the same mild heat treatment at concentrations of 1·75 mmol l−1, 2·5 mmol l−1, 1·5 mmol l−1 and 2 mmol l−1, respectively. These findings show that essential oil compounds can play an important role in minimally processed foods, and can be used in the concept of Hurdle Technology to reduce the intensity of heat treatment or other individual hurdles.

Commonly used farm disinfectants can select for mutant Salmonella enterica serovar Typhimurium with decreased susceptibility to biocides and antibiotics without compromising virulence

Objectives: To determine if one passage of Salmonella enterica serovar Typhimurium in the presence of farm disinfectants selected for mutants with decreased susceptibility to disinfectants and/or antibiotics. Methods: Eight Salmonella Typhimurium strains including field isolates and laboratory mutants were exposed to either a tar oil phenol (PFD) disinfectant, an oxidizing compound disinfectant (OXC), an aldehyde based disinfectant (ABD) or a dairy sterilizer disinfectant (based on quaternary ammonium biocide) in agar. The susceptibility of mutants obtained after disinfectant exposure to antibiotics and disinfectants was determined as was the accumulation of norfloxacin. The proteome of SL1344 after exposure to PFD and OXC was analysed using two-dimensional liquid chromatography mass spectrometry. Results: Strains with either acrB or tolC inactivated were more susceptible to most disinfectants than other strains. The majority (3/5) of mutants recovered after disinfectant exposure required statistically significantly longer exposure times to disinfectants than their parent strains to generate a 5 log kill. Small decreases in antibiotic susceptibility were observed but no mutants were multiply antibiotic-resistant (MAR). Notably exposure to ABD decreased susceptibility to ciprofloxacin in some strains. Mutants with increased disinfectant tolerance were able to survive and persist in chicks as well as in parent strains. Analysis of proteomes revealed significantly increased expression of the AcrAB-TolC efflux system after PFD exposure. Conclusions: Data presented demonstrate that efflux pumps are required for intrinsic resistance to some disinfectants and that exposure to disinfectants can induce expression of the AcrAB-TolC efflux system, but that single exposure was insufficient to select for MAR strains.

Volume-based size distribution of accumulation and coarse particles (PM0.1–10) from cooking fume during oil heating

Particulate matter generated during the cooking process has been identified as one of the major problems of indoor air quality and indoor environmental health. Reliable assessment of exposure to cooking-generated particles requires accurate information of emission characteristics especially the size distribution. This study characterizes the volume/mass-based size distribution of the fume particles at the oil-heating stage for the typical Chinese-style cooking in a laboratory kitchen. A laser-diffraction size analyzer is applied to measure the volume frequency of fume particles ranged from 0.1 to 10 μm, which contribute to most mass proportion in PM2.5 and PM10. Measurements show that particle emissions have little dependence on the types of vegetable oil used but have a close relationship with the heating temperature. It is found that volume frequency of fume particles in the range of 1.0–4.0 μm accounts for nearly 100% of PM0.1–10 with the mode diameter 2.7 μm, median diameter 2.6 μm, Sauter mean diameter 3.0 μm, DeBroukere mean diameter 3.2 μm, and distribution span 0.48. Such information on emission characteristics obtained in this study can be possibly used to improve the assessment of indoor air quality due to PM0.1–10 in the kitchen and residential flat.

Authorised EU health claims for polyphenols in olive oil

There is evidence that various phenolic compounds (such as oleuropein, tyrosol and hydroxytyrosol) found in virgin olive oil may be responsible for the beneficial effects on cardiovascular disease. In the EU there is an authorized health claim that‘olive oil polyphenols contribute to the protection of blood lipids from oxidative stress’ on the basis of human studies showing significantly reduced levels of oxidized LDL in plasma after virgin olive oil consumption. The claim may be used only for olive oil that contains at least 5 mg of hydroxytyrosol and its derivatives per 20 g of olive oil. Other claims proposed (including maintenance of normal blood pressure and HDL cholesterol concentration, and anti-inflammatory properties) were rejected.

Investigations into the formation and characterization of phospholipid microemulsions. IV. Pseudo-ternary phase diagrams of systems containing water-lecithin-alcohol and oil; The influence of oil

Phase studies have been performed for quaternary systems composed of egg lecithin, cosurfactant, water and oil. The lecithin used was the commercially available egg lecithin Ovothin 200 (which comprises ≥ 92% phosphatidylcholine). The cosurfactants employed were propanol and butanol, and these were used at lecithin/cosurfactant mixing ratios (Km) of 1:1 and 1.94:1 (weight basis). Six polar oils were investigated, including the alkanoic acids, octanoic and oleic, their corresponding ethyl esters and the medium and long chain triglycerides, Miglyol 812 and soybean oil. All oils, irrespective of the alcohol and the Km used, gave rise to systems that produced a stable isotropic region along the surfactant/oil axis (designated as a reverse microemulsion system). In addition, the systems incorporating propanol at both Km and butanol at a Km of 1.94: 1, generally gave rise to a liquid crystalline region and, in some cases, a second isotropic non-birefingent area (designated as a normal microemulsion system). The phase behaviour observed was largely dependent upon the alcohol and Km used and the size and the polarity of the oil present.

Evaluating the potential of high pressure high temperature and thermal processing on volatile compounds, nutritional and structural properties of orange and yellow carrots

The present study compares the impact of thermal and high pressure high temperature(HPHT) processing on volatile profile (via a non-targeted headspace fingerprinting) and structural and nutritional quality parameter (via targeted approaches) of orange and yellow carrot purees. The effect of oil enrichment was also considered. Since oil enrichment affects compounds volatility, the effect of oil was not studied when comparing the volatile fraction. For the targeted part, as yellow carrot purees were shown to contain a very low amount of carotenoids, focus was given to orange carrot purees. The results of the non-targeted approach demonstrated HPHT processing exerts a distinct effect on the volatile fractions compared to thermal processing. In addition, different colored carrot varieties are characterized by distinct headspace fingerprints. From a structural point of view, limited or no difference could be observed between orange carrot purees treated with HPHT or HT processes, both for samples without and with oil. From nutritional point of view, only in samples with oil, significant isomerisation of all-trans-β-carotene occurred due to both processing. Overall, for this type of product and for the selected conditions, HPHT processing seems to have a different impact on the volatile profile but rather similar impact on the structural and nutritional attributes compared to thermal processing.

Volatile profile of Spanish Cistus plants as sources of antimicrobials for industrial applications

Cistus is a plant genus traditionally used in folk medicine as remedy for several microbial disorders and infections. The abundance of Cistus spp. in the Iberian Peninsula together with their ability to renew after wildfire contribute to their profitability as suppliers of functional ingredients. The aim of this study was to provide a comprehensive characterization of the volatile profile of different Cistus plants grown in Spain:Cistus ladanifer L., Cistus albidus L., Cistus salviifolius L., and Cistus clusii Dunal (the latter has not been studied before). A system combining headspace solid-phase microextraction and gas chromatography coupled to mass spectrometry (HS-SPME-GC–MS) was implemented; thereby, the volatile compounds were extracted and analyzed in a fast, reliable and environment-friendly way. A total of 111 volatile compounds were identified, 28 of which were reported in Cistus for the first time. The most abundant components of the samples (mono and sesquiterpenes) have been previously reported as potent antimicrobial agents. Therefore, this work reveals the potential use of the Cistus spp. studied as natural sources of antimicrobial compounds for industrial production of cosmeceuticals, among other applications.

Use of TD-GC-TOF-MS to assess volatile composition during post harvest storage in seven accessions of rocket salad (Eruca sativa)

An important step in breeding for nutritionally enhanced varieties is determining the effects of the post-harvest supply chain on phytochemicals and the changes in VOCs produced over time. TD- GC-TOF-MS was used and a technique for the extraction of VOCs from the headspace using portable tubes is described. Forty-two compounds were detected; 39 were identified by comparison to NIST libraries. Thirty-five compounds had not been previously reported in Eruca sativa. Seven accessions were assessed for changes in headspace VOCs over 7 days. Relative amounts of VOCs across 3 time points were significantly different - isothiocyanate-containing molecules being abundant on 'Day 0'. Each accession showed differences in proportions/types of volatiles produced on each day. PCA revealed a separation of VOC profiles according to the day of sampling. Changes in VOC profiles over time could provide a tool for assessment of shelf-life.

Aqueous enzyme assisted oil extraction from oilseeds and emulsion de-emulsifying methods: a review

Regulatory, safety, and environmental issues have prompted the development of aqueousenzymatic extraction (AEE) for extracting components from oil-bearing materials. The emulsion resulting from AEE requires de-emulsification to separate the oil; when enzymes are used for this purpose, the method is known as aqueous enzymatic emulsion de-emulsification (AEED). In general, enzyme assisted oil extraction is known to yield oil having highly favourable characteristics. This review covers technological aspects of enzyme assisted oil extraction, and explores the quality characteristics of the oils obtained,focusing particularly on recent efforts undertaken to improve process economics by recovering and reusing enzymes.

Changes in sewage sludge carbon forms along a treatment stream

The behaviour and fate of macronutrients and pollutants in sewage sludge applied to the land are affected by the chemical composition of the sludge organic matter, which in turn is influenced by both sewage source and by sewage treatment processes. In this study, 13C nuclear magnetic resonance (NMR) spectroscopy was used to characterise the organic matter of sludges collected at three different points along the treatment stream of a municipal sewage works with a domestic catchment. Sludge at the first point, an undigested liquid (UL) sludge, had a substantially different composition to the anaerobically digested (AD) and dewatered sludge cake (DC) materials, which were similar to each other. In particular, the UL sludge contained more alkyl C than the AD or DC sludges. All three sludges were found to contain mobile alkyl C that is poorly observed using the cross polarisation (CP) technique, necessitating the use of the less sensitive, but more quantitatively reliable direct polarisation (DP) technique to obtain accurate distributions of C types.

Nitrogen dynamics under Lolium perenne after a single application of different sewage sludge types from the same treatment stream

Three sludge types from the same treatment stream (undigested liquid, anaerobically digested liquid and dewatered, anaerobically digested cake) were used in a field based tub study. Amendments (4, 8, and 16 Mg dry solid (ds)ha(-1)) were incorporated into the upper 15 cm of a sandy loam soil prior to sowing with rye-grass (Lolium perenne L.). Nitrogen transformations in the soil were determined for the 80 d period following incorporation. Nitrogen uptake and crop yield were measured in the cut sward 35 and 70 d after sowing. The study showed that application of sewage sludge at rates as low as 4 Mgha(-1) can have a nutritional benefit to rye-grass over the two harvests. Differences in N transformation, and hence crop nutritional benefit, between sludge types were evident throughout the experiment. In particular, the dewatering process changed the mineral N characteristics of the anaerobically digested sludge, which, when not dewatered, outperformed the other sludges in terms of yield and mineralisation rate at both harvests. The dewatered sludge produced the lowest yield of rye-grass. The undigested liquid sludge had the lowest foliar N and soil NO(3)-N concentrations, possibly immobilised as the large oxidisable C component of this sludge was metabolised by the microbial biomass. Correlation data support the concept of preferential uptake of NH(4)-N over NO(3)-N in Lolium perenne. Results are discussed in the context of managing sludge type and application for a plant nutrient source and NO(3)-N release.