Oil quality and aroma composition of 'Chemlali' olive trees (Olea europaea L.) under three irrigation regimes

The present work focused on the chemical composition of monovarietal virgin olive oil from the cultivar Chemlali cultivated in the South of Tunisia: sub-arid zone under three different irrigation regimes: stressed, moderate and well irrigation treatment with the restitution of 50, 75 and 100% of crop evapotranspiration (ETc), respectively. Quality characteristics (acidity and peroxide value) and chemical data (antioxidant compound, fatty acids volatile compounds and oxidative stability) were studied in addition to the pomological characteristic of olive fruit. Results show that there were significant differences observed in oil composition according to the irrigation regime applied. Total phenols, bitterness intensity and LOX products content showed the highest values for low irrigation regime, whereas polyunsaturated fatty acid and oxidative susceptibility values had highest values for olive oil from well irrigated trees. Analytic characteristic of fruits showed the highest values of pulp/stone ratios from olive trees irrigated by the highest amount of wate

Prospective study of the primary evaluation of 1016 horses with clinical signs of abdominal pain by veterinary practitioners, and the differentiation of critical and non‑critical cases

Background: The majority of research on the evaluation of horses with colic is focused on referral hospital populations. Early identification of critical cases is important to optimise outcome and welfare. The aim of this prospective study was to survey the primary evaluation of horses with clinical signs of abdominal pain by veterinary practitioners, and compare the initial presentation of critical and non-critical cases. Results: Data from 1016 primary evaluations of horses presenting with clinical signs of colic were submitted by 167 veterinary practitioners across the United Kingdom over a 13 month period. The mean age of the study population was 13.5 years (median 12.0, range 0–42). Mean heart rate on primary presentation was 47 beats/min (median 44, range 18–125), mean respiratory rate was 20 breaths/min (median 16, range 6–100), and median gastrointestinal auscultation score (0–12, minimum–maximum) was 5 (range 0–12). Clinical signs assessed using a behavioural severity score (0–17, minimum–maximum), were between 0 and 6 in 70.4 % of cases, and 7 12 for 29.6 % of cases. Rectal examination was performed in 73.8 % of cases. Cases that responded positively to simple medical treatment were categorised retrospectively as ‘non-critical’; cases that required intensive medical treatment, surgical intervention, died or were euthanased were categorised as ‘critical’. Eight-hundred-and-twenty- two cases met these criteria; 76.4 % were ‘non-critical’ and 23.6 % were ‘critical’. Multivariable logistic regression was used to identify features of the clinical presentation associated with critical cases. Five variables were retained in the final multivariable model: combined pain score: (OR 1.19, P 2.5 s (OR 3.21, P = 0.046, 95 % CI 1.023–10.09), weak pulse character (OR 2.90, P = 0.004, 95 % CI 1.39–5.99) and absence of gut sounds in ≥1 quadrant (OR 3.65, P < 0.001, 95 % CI 2.08–6.41). Conclusions: This is the first study comparing the primary presentation of critical and non-critical cases of abdominal pain. Pain, heart rate, gastrointestinal borborygmi and simple indicators of hypovolaemia were significant indicators of critical cases, even at the primary veterinary examination, and should be considered essential components of the initial assessment and triage of horses presenting with colic

Enhancing surface production of negative ions using nitrogen doped diamond in a deuterium plasma

The production of negative ions is of significant interest for applications including mass spectrometry, particle acceleration, material surface processing, and neutral beam injection for magnetic confinement fusion. Methods to improve the efficiency of the surface production of negative ions, without the use of low work function metals, are of interest for mitigating the complex engineering challenges these materials introduce. In this study we investigate the production of negative ions by doping diamond with nitrogen. Negatively biased ($-20$ V or $-130$ V), nitrogen doped micro-crystalline diamond films are introduced to a low pressure deuterium plasma (helicon source operated in capacitive mode, 2 Pa, 26 W) and negative ion energy distribution functions (NIEDFs) are measured via mass spectrometry with respect to the surface temperature (30$^{\circ}$C to 750$^{\circ}$C) and dopant concentration. The results suggest that nitrogen doping has little influence on the yield when the sample is biased at $-130$ V, but when a relatively small bias voltage of $-20$ V is applied the yield is increased by a factor of 2 above that of un-doped diamond when its temperature reaches 550$^{\circ}$C. The doping of diamond with nitrogen is a new method for controlling the surface production of negative ions, which continues to be of significant interest for a wide variety of practical applications

Oxidative evolution of virgin and flavored olive oils under thermo-oxidation processes

Changes in the oxidative status of Chetoui olive oil were monitored to attest the efficiency of some bioactive compounds from aromatic plants to improve the stability of olive oils after a maceration process at different concentrations. Aromatized olive oils were prepared by addition of lemon and thyme extracts at four different concentrations (20–80 g kg-1 of oils) to virgin olive oils. The following parameters were monitored: free fatty acids, peroxide value, ultra violet absorption characteristics at 232 and 270 nm, fatty acid composition and aromatic profiles. After thermo-oxidation processes, the oleic/linoleic acid ratio remained stable (4.5). Oxidative stability slightly decreased during thermo-oxidation processes. The heating of the oils changed their volatile profile and led to the formation of new volatile compounds, such as the two isomers of 2,4-heptadienal after heating at 100°C or (E,Z)-2,4-decadienal and (E,E)-2,4-decadienal after thermo-oxidation at 200°C. The use of lemon and thyme extracts modified the aromatic and the nutritional value of the olive oil by the transfer of some bioactive compounds, such as limonene and carvacrol. In contrast, the oxidative stability of the product did not change. Furthermore, the aromatized oils may be employed in seasoning and cooking of some food

Thick and widened high quality heavily boron doped diamond single crystals synthetized with high oxygen flow under high microwave power regime

International audienceThe aim of this paper is to optimize the growth conditions of thick boron doped diamond single crystals, which requires the use of high microware power density to have high growth rate, in order to allow enlarging CVD deposited layers keeping both high boron doping level and high crystal quality. It is shown that the use of a high amount of oxygen (1 to 2%) in the gas phase leads to 1 mm lateral growth after the growth of 500 μm thick CVD diamond layer. Thus, the surface is increased from 10 mm² to 18 mm². The obtained films exhibit high crystal quality confirmed by Raman spectroscopy and confocal microscopy. Depending on the gas composition introduced in the reactor, the boron concentration varied between 5×1019 at/cm3 and 3×1020 at/cm3 as measured by SIMS

Investigation of a distributed antenna array microwave system for the three-dimensional low-temperature growth of nanocrystalline diamond films

International audienc

Volatile and nonvolatile chemical composition of some date fruits (Phoenix dactylifera L.) harvested at different stages of maturity

Physico-chemical and aroma volatile compositions of three date palm cultivars were studied throughout fruit maturation (besser, rutab and tamr stages) during 2008 harvest season. The studied parameters varied significantly through the different stages, with some variations also depending on the cultivar. Length and width of the three types of dates showed a progressive decrease during ripening. The pH level, total sugars and ash contents significantly increased up to tamr stage. Conversely, moisture, lipid and protein contents decreased. The profile of the volatile aroma compounds was evaluated using solid-phase micro-extraction. Sixty-nine compounds were detected during maturation, accounting from 98.5% to 99.6% at besser, 93.1% to 99.2% at rutab and 94.3% to 98.4% at tamr stages of the total identified volatiles. The present study sheds more light on chemical characteristics of the studied cultivars that can be used in many industrial processe

Volatile compounds and compositional quality of virgin olive oil from Oueslati variety: Influence of geographical origin

Headspace solid-phase microextraction (HS-SPME) was applied to the analysis of volatile compounds of virgin olive oils from Oueslati variety cultivated in different geographical areas. Thus, olives at the same stage of maturation were harvested from seven regions in the Centre and the South of the country for oil extraction and analysis. Twenty-seven compounds were characterised by GC-FID and GC–MS. Compounds belonging mainly to alcohols, esters, aldehydes, ketones and hydrocarbons chemical classes characterised the volatile profiles. Significant differences in the proportion of volatiles from oils of different geographical origins were detected. The results suggest that, besides genetic factors, environmental conditions influence volatile formatio