The viscoelastic properties of processed cheeses depend on their thermal history and fat polymorphism

Both the composition and the thermal kinetics that are applied to processed cheeses can affect their texture. This study investigated the effect of the storage conditions and thermal history on the viscoelastic properties of processed cheese and the physical properties of the fat phase. The microstructure of processed cheese has been characterized. Using a combination of physical techniques such as rheometry, differential scanning calorimetry, and X-ray diffraction, the partial crystallization of fat and the polymorphism of triacylglycerols (TG; main constituents of milk fat) were related to changes in the elastic modulus and tan δ as a function of temperature. In the small emulsion droplets (<1 μm) dispersed in processed cheeses, the solid fat phase was studied at a molecular level and showed differences as a function of the thermal history. Storage of processed cheese at 4 °C and its equilibration at 25 °C lead to partial crystallization of the fat phase, with the formation of a β' 2 L (40.9 ?) structure; on cooling at 2 °C min(-1), the formation of an α 3 L (65.8 ?) structure was characterized. The cooling of processed cheese from 60 to -10 °C leads to the formation of a single type of crystal: α 3 L (72 ?). Structural reorganizations of the solid fat phase characterized on heating allowed the interpretation of the elastic modulus evolution of processed cheese. This study evidenced polymorphism of TG in a complex food product such as processed cheese and allowed a better understanding of the viscoelastic properties as a function of the thermal history.     

Heavy Metals in Soil, Crops and Grass as a Source of Human Exposure in the Former Mining Areas (6 pp)

Background, Aim and Scope   In the former mining area of Northern France, the number of diseases (cancers, malformations, backwardness...) is about ten times above the national average. Environmental surveys conducted by the Ministry of Health have showed that more than 10% of children living around a lead smelter located in this area had lead levels higher than 100 μg L-1 of blood (25% in the closest city). Two main factors contribute to the population exposure: the ingestion of plants produced in the contaminated area, and also the ingestion or the inhalation of contaminated dust or soil. It is usually known that these particles are key routes of exposure to lead for younger children, in particular via hand-to-mouth transfer. For a better understanding of this problem, researchers investigated different exposure sources like soil and vegetable contamination. Materials and Methods: All these parameters that contribute to the assessment of environmental and health risks of metal contamination have been measured. About 170 composite samples of soils around the smelter or from reference areas have been analysed, mainly from fields (70), kitchen gardens (60) and lawns (38). Total contents of Cd and Pd were measured in the organo-mineral layer (0-25cm) of soils. Composite grass samples were also taken on the lawns. Crops and vegetables were sampled from fields and kitchen gardens and then, parts of the plant intended only for consumption were washed and analysed. Results: For the organo-mineral horizon of the studied sites and located in various environmental contexts (contaminated or reference), we found a very broad range of metal concentrations. Generally, the data showed a strong variability of the physicochemical parameters of the urban soils (kitchen gardens, lawns), in particular with regard to lead. This work showed that cultivated plants (agricultural or kitchen garden) or lawn grass are also significantly contaminated by heavy metals, especially lawn grasses, cereal grains (wheat, barley) and lettuces sampled around the smelter. Moreover, the proportion of lead present on lawn grasses could reach 50% of the total contamination of the plants because of the deposition of contaminated dust. Discussion: The values of pollution in agricultural field and kitchen garden soils located near the smelter were respectively about 20 and 30 times above the agricultural regional reference values, probably due to the atmospheric emissions from a smelter that significantly increases the concentrations of metals in the upper horizons of the neighbouring soils. This pollution results in a high level of contamination of plants grown of these soils. Conclusions: The results showed that heavy metals in soils, particles (dust and soil) or plants of kitchen gardens, lawns or playgrounds could be potentially transferable to the users, and in particular to young children, and could then contribute, to a considerable share, to the exposure of the population living in a contaminated area around a smelter brought about through inhalation, direct ingestion of particles or consumption of plants. Recommendations and Perspectives: These results highlight that the consumption of home-grown vegetables can constitute a risk of exposure, in particular for cadmium, and especially in children. This work also underlined the role of the contaminated soil particles in the Pb contamination of the human food chains and their environment. Because of the complexity of the various methods of population exposure, it will be necessary to complete the data base, in partucular in urban areas. The main objective of this future work will be to relate the degree of environmental contamination with the lead level in child bood, and to integrate other environmental compartments like outdoor and indoor dust of the dwellings into the model of pathway exposure.     

Experimental infection of SPF pigs with Actinobacillus pleuropneumoniae serotype 9 alone or in association with Mycoplasma hyopneumoniae

The purpose of this study was to compare in SPF pigs, the pathogenicity of an Actinobacillus pleuropneumoniae serotype 9 strain 21 (isolated from the palatine tonsils of a healthy gilt on a French nucleus pig farm, with no clinical signs or lung lesions but a highly positive reaction to A. pleuropneumoniae serotype 9 antibodies) with a pathogenic A. pleuropneumoniae strain 4915 serotype 9 (isolated in France from an outbreak of porcine pleuropneumonia). The pathogenicity of one Mycoplasma hyopneumoniae strain alone or associated with A. pleuropneumoniae strain 21 was also compared. Eight groups of 7 pigs were infected (at 6 or 10 weeks of age) and a control group was kept non-infected. Results showed that sensitivity to A. pleuropneumoniae was related to the age of the pig (6 weeks vs 10 weeks) whatever the strain. Surviving pigs infected at 6 weeks of age developed severe clinical signs, lung lesions typical of A. pleuropneumoniae and they seroconverted. In contrast, symptoms and lung lesions were almost non-existent in pigs infected with strain 21 at 10 weeks of age, but a seroconversion was observed with very high ELISA titres. These results were in accordance with those observed in the nucleus pig farm. Infection with M. hyopneumoniae alone induced typical mycoplasmal symptoms, pneumonia and seroconversion. Symptoms and lung lesions were the most noticeable in pigs infected with M. hyopneumoniae at 6 weeks of age and with A. pleuropneumoniae 4 weeks later. Our results show that the presence of A. pleuropneumoniae serotype 9 in a pig herd may be clinically unnoticed and that M. hyopneumoniae may potentiate A. pleuropneumoniae infection.     

Consequences of hydrological events on the delivery of suspended sediment and associated radionuclides from the Rh?ne River to the Mediterranean Sea

Purpose

Almost 20 nuclear reactors are situated along the Rh?ne valley, representing Europe??s largest concentration of nuclear power plants. The fate of suspended sediments and natural and artificial particle-bound radionuclides in relation to extreme hydrological events was assessed at the lower course of the Rh?ne River, which provides the main source of water and sediment inputs to the northwestern Mediterranean Sea.

Materials and methods

We sampled water at a high frequency over the period 2001?C2008 and measured suspended particulate matter (SPM) loads and particle-bound natural and artificial radionuclide concentrations at the SORA observatory station in Arles, France. We monitored various hydrological events (either natural or anthropogenic origin) and characterize their influence on concentrations and fluxes.

Results and discussion

The relationship between SPM concentration and the very wide range of water discharges did not differ significantly from previous periods, indicating no significant shift in the average sediment delivery over the last 20?years. Unexpected hydrological events of anthropogenic origin, in particular those associated with flushing of reservoirs that are generally not captured by sampling strategies, were recorded and were shown to transfer significant additional sediment and associated contaminants towards the marine environment. Concentrations of anthropogenic radionuclides associated with sediment (i.e., ¹³⁷Cs, ⁶⁰Co, ⁵⁴Mn, ^110mAg, and Pu isotopes) varied over two to three orders of magnitude during periods of low and moderate flow due to variations in the liquid release from nuclear facilities. Except for Pu isotopes, the concentrations of the various particle-bound radionuclides generally showed a decreasing trend with increasing discharge, revealing the geochemical or anthropogenic background values, and providing a useful flood fingerprint for this large fluvial system before its entry into the marine environment.

Conclusions

Our approach produced key data on the level and fate of suspended solids and radionuclide concentrations during flood events occurring in a large river system that could be contaminated by chronic or accidental radioactive releases. These results are of fundamental importance for further interpretations of sediment dynamics at the river mouth.     

An investigation of the versatile antioxidant mechanisms of action of rosmarinate alkyl esters in oil-in-water emulsions

The antioxidant polar paradox postulates that nonpolar antioxidants are more effective in oil-in-water emulsions than polar antioxidants. However, this trend is often not observed with antioxidants esterified with acyl chains to vary their polarity. In this study, the nonpolar eicosyl rosmarinate (20 carbons, R20) was less effective at inhibiting lipid oxidation in oil-in-water emulsions than esters with shorter fatty acyl chains such as butyl (R4), octyl (R8), and dodecyl (R12) esters. Interestingly, in the presence of surfactant micelles, the antioxidant activity of R20 was significantly increased while the antioxidant activity of R4 and R12 was slightly decreased. The presence of surfactant micelles increased the concentration of R20 at the interface of the surfactant micelles and/or emulsion droplets as determined by partitioning studies, front-face fluorescence properties, and the ability of R20 to interact with the interfacial probe, 4-hexadecylbenzenediazonium. A possible explanation for why the antioxidant activity of R20 was so dramatically increased by surfactant micelles is that a portion of the nonpolar R20 localizes in the emulsion droplet core and the surfactant micelles are able to increase the interfacial concentrations of R20 and thus its ability to scavenge free radicals produced from the decomposition of interfacial lipid hydroperoxides.     

Successful treatment of severe salt intoxication in a dog

Objective: To report successful treatment of severe salt intoxication and hypernatremia in a dog. Case summary: A 5‐year‐old intact female Doberman Pinscher was admitted to the intensive care unit with a history of seizures and coma. The owner had administered approximately 100 g of cooking salt to induce vomiting following ingestion of a nontoxic dose (10 g) of chocolate. Upon admission, the dog was comatose with intermittent seizures and vomiting. Diagnostic tests confirmed salt intoxication (Na: 200 mEq/L, Cl: 180 mEq/L) and metabolic acidosis (pH: 7.18; pCO₂: 39 mmHg; HCO₃: 14.3 mmol/L). Immediate treatment included intravenous fluid therapy, an anticonvulsant, antiemetic, diuretic, low molecular weight heparin, and supplemental oxygen. A fluid therapy protocol was initiated to decrease serum sodium concentration by approximately 2 mEq/L/hr. After 24 hours of intensive care, the patient regained consciousness and volume and acid‐base abnormalities improved. The patient developed a variety of abnormal clinical signs as a result of the severe hypernatremia. After 5 days of treatment, the serum sodium concentration returned to the established reference range. The patient recovered completely in 10 days. New information provided: Severe hypernatremia due to salt ingestion is a rare condition in dogs. All dogs in previous case reports of salt intoxication have died. This case report is the first to report survival of a dog with severe salt intoxication.     

Preliminary pharmacokinetics of tramadol hydrochloride after administration via different routes in male and female B6 mice

Objective

1) To determine the pharmacokinetics of tramadol hydrochloride and its active metabolite, O-desmethyltramadol (M1), after administration through different routes in female and male C57Bl/6 mice; 2) to evaluate the stability of tramadol solutions; and 3) to identify a suitable dose regimen for prospective clinical analgesia in B6 mice.

Phospholipid, sphingolipid, and fatty acid compositions of the milk fat globule membrane are modified by diet

The phospholipid and sphingolipid composition of milk is of considerable interest regarding their nutritional and functional properties. The objective of this article was to determine the lipid composition of the milk fat globule membrane (MFGM) of milk from cows fed a diet rich in polyunsaturated fatty acids. The experiments were performed with 2 groups of 6 cows feeding on (i) maize silage ad libitum (+ grassland hay, mixture of cereals, soyabean meal) or (ii) the maize silage-based diet supplemented with extruded linseed (bringing a lipid proportion of 5% of dry matter). The phospholipid and sphingolipid composition of the MFGM was determined using HPLC/ELSD. The fatty acid (FA) composition of total lipids and phospholipids was determined using GC. As expected, the linseed-supplemented diet decreased the saturated FA and increased the unsaturated FA content in milk fat. MFGM in milk from cows fed the diet rich in polyunsaturated FA resulted in (i) a higher amount of phospholipids (+ 18%), which was related to a smaller size of milk fat globules (ii) an increase of 30% (w/w) of the concentration in sphingomyelin, (iii) a higher content in stearic acid (1.7-fold), unsaturated FA (1.36-fold), and C18:1 trans FA: 7.2 +/- 0.5% (3.7-fold). The MFGM contained a higher concentration of unsaturated FA (C18:1, C18:2, and C18:3) and very long-chain FA (C22:0, C23:0, C24:0, EPA, DHA) compared with total lipids extracted from milk. The technological, sensorial, and nutritional consequences of these changes in the lipid composition of the MFGM induced by dietary manipulation remain to be elucidated.     

Changes in Fatty Acid Composition and Content of Two Plants (Lolium perenne and Trifolium repens) Grown During 6 and 18 Months in a Metal (Pb, Cd, Zn) Contaminated Field

The aim of this in situ study was to investigate the fatty acid (FA) composition and content in roots and shoots of Lolium perenne and Trifolium repens, grown under heavy metal stress (Cd, Pb, Zn). The composition of FA was quite similar for the two plants and the two organs; main FA were palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). For both plants, the major FA that characterized the roots was C18:2 whereas C18:3 was the prominent FA in shoots. For the first sampling (S1), in the roots of L. perenne and T. repens, polyunsaturated fatty acids (PUFA) were affected by metal contamination while, in the second sampling (S2), PUFA were affected in the shoots of the two plants. This alteration of PUFA was well correlated with the bioaccumulation factor of metals which decreased in roots and increased in shoots with the time. Moreover, a positive correlation was found between the PUFA decrease and the malondialdehyde (MDA) content, indicating the occurrence of a lipid peroxidation induced by the metal stress.