Pyrolysis-gas chromatography-isotope ratio mass spectrometry for monitoring natural additives in polylactic acid active food packages.

Compound-specific isotope analysis (CSIA) usually requires preparative steps (pretreatments, extraction, derivatization) to get amenable chromatographic analytes from bulk geological, biological or synthetic materials. Analytical pyrolysis (Py-GC/MS) can help to overcome such sample manipulation. This communication describe the results obtained by hyphenating analytical pyrolysis (Py-GC) with carbon isotope-ratio mass spectrometry (IRMS) for the analysis of a polylactic acid (PLA) a based bio-plastic extruded with variable quantities of a natural plant extract or oregano essential oil. The chemical structural information of pyrolysates was first determined by conventional analytical pyrolysis and the measure of δ13C in specific compounds was done by coupling a pyrolysis unit to a gas chromatograph connected to a continuous flow IRMS unit (Py-GC-C-IRMS). Using this Py-CSIA device it was possible to trace natural additives with depleted δ13C values produced by C3 photosystem vegetation (cymene: -26.7‰±2.52; terpinene: -27.1‰±0.13 and carvacrol: -27.5‰±1.80 from oregano and two unknown structures: -23.3‰±3.32 and -24.4‰±1.70 and butyl valerate: -24.1‰±3.55 from Allium spp.), within the naturally isotopically enriched bio-plastic backbone derived from corn (C4 vegetation) starch (cyclopentanones: -14.2‰±2.11; lactide enantiomers: -9.2‰±1.56 and larger polymeric units: -17.2‰±1.71). This is the first application of Py-CSIA to characterize a bio-plastic and is shown as a promising tool to study such materials, providing not only a fingerprinting, but also valuable information about the origin of the materials, allowing the traceability of additives and minimizing sample preparation.

A subchronic 90-day oral toxicity study of Origanum vulgare essential oil in rats.

Oregano essential oil (Origanum vulgare L. virens) (OEO) is being used in the food industry due to its useful properties to develop new active packaging systems. In this concern, the safety assessment of this natural extract is of great interest before being commercialized. The European Food Safety Authority requests different in vivo assays to ensure the safety of food contact materials. One of these studies is a 90 days repeated-dose oral assay in rodents. In the present work, 40 male and 40 female Wistar rats were orally exposed to 50, 100 and 200 mg/kg body weight (b.w.) OEO during 90 days following the OECD guideline 408. Data revealed no mortality and no treatment-related adverse effects of the OEO in food/water consumption, body weight, haematology, biochemistry, necropsy, organ weight and histopathology. These findings suggest that the oral no-observed-adverse-effect level (NOAEL) of this OEO is 200 mg/kg b.w. in Wistar rats, the highest dose tested. In conclusion, the use of this OEO in food packaging appears to be safe based on the lack of toxicity during the subchronic study at doses 330-fold higher than those expected to be in contact consumers in the worst scenario of exposure.

Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging.

Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.

Toxicological evaluation of an Allium-based commercial product in a 90-day feeding study in Sprague-Dawley rats.

Proallium AP(®) is a commercial Allium extract intended to be used in active food packaging as the antibacterial and antioxidant effects of some organosulfur compounds are well known. However, there is little information on its toxicity and the Scientific Committee on Food (UE) requires the safety assessment of substances used in food contact materials. Thus, the aim of this study was to conduct for the first time a subchronic oral toxicity study of Proallium AP(®) with groups of 10 males and 10 females Sprague-Dawley rats fed a diet containing 0, 25, 100, 400 mg/kg/d for 90 days. No treatment-related clinical signs or mortality were noted. Besides, no treatment-related effects with regard to any of the toxicological biomarkers considered were observed, including biochemical, haematological and histopathology parameters. In conclusion, the non-observed-adverse-effect-level (NOAEL) for Proallium AP(®) in rats was determined to be a dietary dose of 400 mg/kg/d under the present experimental conditions, a value 500-fold higher than the exposure derived from its potential use in active packaging.

Genotoxicity assessment of propyl thiosulfinate oxide, an organosulfur compound from Allium extract, intended to food active packaging.

Essential oils from onion (Allium cepa L.), garlic (Allium sativum L.), and their main components, such as propyl thiosulfinate oxide (PTSO) are being intended for active packaging with the purpose of maintaining and extending food product quality and shelf life. The present work aims to assess for the first time the potential mutagenicity/genotoxicity of PTSO (0-50 µM) using the following battery of genotoxicity tests: (1) the bacterial reverse-mutation assay in Salmonella typhimurium (Ames test, OECD 471); (2) the micronucleus test (OECD 487) (MN) and (3) the mouse lymphoma thymidine-kinase assay (OECD 476) (MLA) on L5178YTk(+/-), cells; and (4) the comet assay (with and without Endo III and FPG enzymes) on Caco-2 cells. The results revealed that PTSO was not mutagenic in the Ames test, however it was mutagenic in the MLA assay after 24 h of treatment (2.5-20 µM). The parent compound did not induce MN on mammalian cells; however, its metabolites (in the presence S9) produced positive results (from 15 µM). Data from the comet assay indicated that PTSO did not induce DNA breaks or oxidative DNA damage. Further in vivo genotoxicity tests are needed to confirm its safety before it is used as active additive in food packaging.

Estudio in vitro de la viabilidad de células Caco-2 en presencia de componentes del aceite esencial de Allium spp / In vitro study of the viability of Caco-2 cells in presence of two compound of Allium spp essential oil

El aceite esencial de los componentes del género Allium, principalmente ajo y cebolla, presenta propiedades antioxidantes y antibacterianas debidas a la presencia de compuestos azufrados en su composición. La industria alimentaria ha comenzado a desarrollar nuevos sistemas de envasado activo a partir de polímeros seleccionados, a los que se incorporan aceites esenciales que, por sus propiedades, contribuyen a aumentar la vida útil de los alimentos perecederos. En este sentido, se hace necesario evaluar la seguridad asociada al uso de estas sustancias en envases alimentarios que van a estar en contacto con el consumidor a través del alimento. El objetivo del presente estudio fue determinar la citotoxicidad producida por dipropil sulfuro y dipropil disulfuro, dos de los componentes del aceite esencial de ajo y cebolla, en la línea celular Caco-2, células humanas procedentes de carcinoma de colon. Los biomarcadores ensayados fueron el contenido total de proteínas, la captación de rojo neutro y la reducción de la sal de tetrazolio (3-(4,5-dimetiltiazol-2- il)-5-(3-carboximetoxifenil)-2-(4sulfofenil)-2H-tetrazolio). Las células fueron expuestas durante 2, 4 y 8 h a concentraciones comprendidas entre 0 y 200 μM. Los resultados no mostraron diferencias significativas frente al control para ninguno de los tres marcadores, lo que demuestra que bajo las condiciones de los ensayos ambos compuestos azufrados no son citotóxicos para esta línea celular gastrointestinal y podrían ser útiles en la industria alimentaria para desarrollar envases activos (AU)

Allium spp. essential oil, mainly from garlic and onion, possesses different beneficial properties, for example antioxidant and antimicrobial effects, due to the presence of sulfur compounds. Food industry is developing new active packaging systems that include the essential oil of garlic in their structure, in order to improve the shelf-life of perishable products. Therefore it is necessary to evaluate the safety associated with the use of these substances in food packaging that will be in contact with the consumer through food. The aim of our study was to evaluate in vitro the cytotoxicity of dipropyl sulfide and dipropyl disulfide. For this purpose, we used the human Caco-2 cell line, from human small intestinal mucosa carcinoma. The assayed cytotoxicity biomarkers were the total protein content, neutral red uptake and reduction of the 3-(4,5-dimethylthiazol-2-yl)-5-(3- carboximethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt. Cells were exposed to dipropyl sulfide and dipropyl disulfide in concentrations between 0-200 μM for 2, 4 and 8 h. After periods of exposure, no alterations were observed in any of the biomarkers assayed. These results suggest that both organosulfur compounds are safety options for food industry and could be a choice in the development of active packaging. (AU)

Normal values in ambulatory oesophageal pH monitoring at two levels in Spain.

AIM: Upper oesophageal pH monitoring may play a significant role in the study of extra-oesophageal GERD, but limited normal data are available to date. Our aim was to develop a large series of normal values of proximal oesophageal acidification. METHODS: 155 healthy volunteers (74 male) participated in a multi-centre national study including oesophageal manometry and 24 hours oesophageal pH monitoring using two electrodes individually located 5 cm above the LOS and 3 cm below the UOS. RESULTS: 130 participants with normal manometry completed all the study. Twelve of them were excluded for inadequate pH tests. Twenty-seven subjects had abnormal conventional pH. The remaining 91 subjects (37 M; 18-72 yrs age range) formed the reference group for normality. At the level of the upper oesophagus, the 95th percentile of the total number of reflux events was 30, after eliminating the meal periods 22, and after eliminating also the pseudo-reflux events 18. Duration of the longest episodes was 5, 4 and 4 min, respectively (3.5 min in upright and 0.5 min in supine). The upper limit for the percentage of acid exposure time was 1.35, 1.05 and 0.95%, respectively. No reflux events were recorded in the upper oesophagus in 8 cases. CONCLUSION: This is the largest series of normal values of proximal oesophageal reflux that confirm the existence of acid reflux at that level in healthy subjects, in small quantity and unrelated to age or gender. Our data support the convenience of excluding pseudo-reflux events and meal periods from analysis.

Actualización en el tratamiento de la infección bronquial / No disponible

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El lóbulo de la vena ácigos / No disponible

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Neumotórax espontáneo bilateral / Bilateral spontaneous pneumothorax

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[Caroli's syndrome: a variable entity]. / Síndrome de Caroli: una entidad variable.

We present the case of a 56 year old woman with Caroli's disease associated to congenital liver fibrosis, renal nephrocalcinosis and cutaneous vasculitis of the legs. Clinical signs of portal hypertension were treated by a shunt technique. After an asymptomatic period, the patient suffers now from crisis of angiocholitis.

[Splenic artery aneurysm. Apropos 3 cases]. / Aneurisma de la arteria esplénica. A propósito de 3 casos.

3 cases of aneurysm of the splenic artery are presented. The incidence of this disease in the general population is not particularly low, however, it is not often diagnosed as it is not symptomatic. 2 of our patients were admitted because of abdominal pain, one of them with acute abdomen and shock and the other had two periods of symptoms with a nonsymptomatic interval between them; both patients had aneurysm resection and splenectomy. The third patient was non-symptomatic and the aneurysm was discovered due to a ring-like calcification. We highlight the value of a contrast CT scan in order to diagnose splenic artery aneurysms.

[Pneumatosis coli vs. deep cystic colitis]. / Pneumatosis coli vs. colitis quística profunda.

We present the case of a 63-year-old female who with no previous history presented with episodes of self-limited diarrhea without fever, general repercussions, abnormal elements or tenesmus. Biochemistry: no abnormality. Parasite and feces culture: negative. Colonoscopy: at 20 to 40 cm from the anal margin were found polypoid lesions covered with normal mucosa. Barium enema confirmed the presence of multiple lacunar defects and possible parietal gas. Biopsy: submucous cysts with foreign body type giant cells. Mixed infiltrate. The differential diagnosis was made between intestinal enterogenous cyst, lymphangioma, retractable mesenteritis and deep cystic colitis, concluding with pneumatosis coli that evolved favorably.