Hepatic fibrogenesis requires sympathetic neurotransmitters

Background and aims: Hepatic stellate cells (HSC) are activated by liver injury to become proliferative fibrogenic myofibroblasts. This process may be regulated by the sympathetic nervous system (SNS) but the mechanisms involved are unclear. Methods: We studied cultured HSC and intact mice with liver injury to test the hypothesis that HSC respond to and produce SNS neurotransmitters to promote fibrogenesis. Results: HSC expressed adrenoceptors, catecholamine biosynthetic enzymes, released norepinephrine (NE), and were growth inhibited by α- and β-adrenoceptor antagonists. HSC from dopamine β-hydroxylase deficient (Dbh(−/−)) mice, which cannot make NE, grew poorly in culture and were rescued by NE. Inhibitor studies demonstrated that this effect was mediated via G protein coupled adrenoceptors, mitogen activated kinases, and phosphatidylinositol 3-kinase. Injury related fibrogenic responses were inhibited in Dbh(−/−) mice, as evidenced by reduced hepatic accumulation of α-smooth muscle actin(+ve) HSC and decreased induction of transforming growth factor β1 (TGF-β1) and collagen. Treatment with isoprenaline rescued HSC activation. HSC were also reduced in leptin deficient ob/ob mice which have reduced NE levels and are resistant to hepatic fibrosis. Treating ob/ob mice with NE induced HSC proliferation, upregulated hepatic TGF-β1 and collagen, and increased liver fibrosis. Conclusions: HSC are hepatic neuroglia that produce and respond to SNS neurotransmitters to promote hepatic fibrosis

Evaluation and predictive modeling of shelf life of minced beef meat stored in high-oxygen modified atmosphere packaging at different temperatures

The aims were: (1) to follow the freshness decay of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures (4.3, 8.1 and 15.5 \ub0C) by applying traditional methods (microbiological counts, color evaluation, thiobarbituric acid assay TBA, headspace gas composition) and e-nose; (2) to model the decay kinetics to obtain information about the maximum shelf life as function of storage conditions. The minced beef, packaged in modified atmosphere was supplied by a manufacturer at the beginning of its commercial life. The study demonstrated the ability of the traditional methods to describe the kinetics of freshness decay. The modeling of the experimental data and the comparison with microbiological or chemical thresholds allowed the setting, for each index, of a stability time above which the meat was no longer acceptable. The quality decay of meat was also evaluated by the headspace fingerprint of the same set of samples by means of a commercial e-nose. A clear discrimination between \u201cfresh\u201d and \u201cold\u201d samples was obtained using PCA and CA, determining at each temperature a specific range of stability time. The mean value of the stability times calculated for each index was 9 days at 4.3 \ub0C (recommended storage temperature), 3\u20134 days at 8.1 \ub0C (usual temperature in household refrigerators) and 2 days at 15.5 \ub0C (abuse temperature). Resolution of the stability times allowed calculation of mean Q10 values, i.e. the increase in rate for a 10 \ub0C increase in temperature. The results show that the Q10 values from the traditional methods (3.6\u20134.0 range) overlapped with those estimated with e-nose and color indexes (3.4 and 3.9, respectively)

Monovarietal extra-virgin olive oil classification: a fusion of human sensory attributes and an electronic tongue

Olive oil quality grading is traditionally assessed by human sensory evaluation of positive and negative attributes (olfactory, gustatory, and final olfactorygustatory sensations). However, it is not guaranteed that trained panelist can correctly classify monovarietal extra-virgin olive oils according to olive cultivar. In this work, the potential application of human (sensory panelists) and artificial (electronic tongue) sensory evaluation of olive oils was studied aiming to discriminate eight single-cultivar extra-virgin olive oils. Linear discriminant, partial least square discriminant, and sparse partial least square discriminant analyses were evaluated. The best predictive classification was obtained using linear discriminant analysis with simulated annealing selection algorithm. A low-level data fusion approach (18 electronic tongue signals and nine sensory attributes) enabled 100 % leave-one-out cross-validation correct classification, improving the discrimination capability of the individual use of sensor profiles or sensory attributes (70 and 57 % leave-one-out correct classifications, respectively). So, human sensory evaluation and electronic tongue analysis may be used as complementary tools allowing successful monovarietal olive oil discrimination.This work was co-financed by FCT/MEC and FEDER under Program PT2020 (Project UID/EQU/50020/2013); by Fundacao para a Ciencia e Tecnologia under the strategic funding of UID/BIO/04469/2013 unit; and by Project POCTEP through Project RED/AGROTEC-Experimentation network and transfer for development of agricultural and agro industrial sectors between Spain and Portugal

NUOVI CAMPI APPLICATIVI DELLA SPETTROSCOPIA NIR PER IL CONTROLLO DI PROCESSO E DI PARAMETRI QUALITATIVI DEI PRODOTTI ALIMENTARI

The aim of this study was to examine the ability of FT-NIR spectroscopy to monitor the food quality and the process kinetics. In particular this technique was applied to the shelf life evaluation of dairy product, such as packed industrial Ricotta and Crescenza cheese stored at constant temperature for different times. This technique was also used to study the cooking kinetics of milled, parboiled and quick cooking rice samples. FT-NIR spectroscopy was used with some success to investigate macromolecular changes during yeasted bread doughs proofing and bread staling. Comparison of results from FT-NIR spectra, electronic nose, image analysis and calorimetric technique was carried out. FT-NIR was shown to have considerable merit in following chemical-physical modifications involved during a process and thus the potential to be used as on-line method for controlling macromolecular changes during storage, cooking, dough proving and bread staling

Monitoring the shelf life of minced beef meat using NIR and MIR spectroscopy

Introduction En travaillant dans des pays du Sud divers et en occupant des fonctions variées, j’ai eu plusieurs occasions de mener des partenariats avec des interlocuteurs d’institutions publiques et privées. Par exemple, en 1995-1997, en tant que coordinatrice des missions de Médecins du monde en Angola, il me fallait négocier sur place les modalités de mise en œuvre de programmes de soins à la fois avec les représentants d’Écho (l’office humanitaire de la Communauté européenne) et les baill..

Effects of osmo-air dehydration treatments on chemical, antioxidant and morphological characteristics of blueberries

Osmo-air dehydration treatments are widely applied to fruits in order to prolong shelf-life, reduce packaging and logistic costs, and to improve both sensory and nutritional quality of the end products. In this work, osmo-air dehydration was applied to blueberries (Vaccinium corymbosum); blanched blueberries were dipped in sucrose (60 Bx) and fructose/glucose (48.6 Bx) osmotic solutions (aw \ubc 0.90) for 24 h, and the osmotic exchanges were determined by mass balances (water loss, solid gain, sugar intake, changes in total phenolics and anthocyanins). Untreated and infused berries were subsequently air dried at 70 C to final moisture content of 10e14%, and drying kinetics as well as compositional and morphological changes of berries were followed in the course of drying. Data show that the osmotic treatment causes significant losses in the antioxidant components (total phenolics, total and individual anthocyanins) and in the antioxidant activity. Losses in the antioxidant components also occur in the course of air drying, with similar kinetics in untreated and infused blueberries. Glucose/fructose infusion gives better results in terms of morphological changes, with lower shrinkage and wrinkling of the berries

Spectroscopic techniques coupled with chemometric tools for the evaluation of light induced oxidation in cheese

Aim of this study was to evaluate the application of these methods, combined with chemometric strategies, as non-destructive techniques to evaluate the light induced oxidation in cheese. Semi hard cheese (Edam cheese) was cut in slices with 1 cm thickness and wrapped with clear cling polyethylene film. Samples were stored in a refrigerated industrial display cabinet equipped with fluorescent lights. The light-induced oxidation of samples, stored in the light and in the dark, was monitored by UV-Vis (200-780 nm), FT-NIR (12,500-3,900 cm-1), FT-IR (4,000-700 cm-1) and fluorescence spectroscopy. The overall results have shown that spectroscopic methods are very sensitive to measure the development of light-induced oxidation in cheese products. In particular UV-VIS and fluorescence spectroscopy detected riboflavin decay that appears to be the most light absorbing constituent of cheese

Shelf life evaluation of fresh-cut pineapple using an electronic nose

The aim of this work was to investigate the applicability of a commercial electronic nose in monitoring freshness of minimally processed fruit (packaged pineapple slices) during storage. The pineapple samples were taken at the beginning of their commercial life and stored at three different temperatures(4\u20135, 7\u20138, and 15\u201316 \u25e6C) for 6\u201310 days. The measurements were performed by applying two analytical approaches using an electronic nose: a discontinuous method being a series of analyses on samples taken at various stages of storage, and a continuous method where the headspace around the fruit was automatically monitored by the electronic nose probe during the preservation of slices in a storage cell. The results obtained by the discontinuous approach showed that the electronic nose was able to discriminate between several samples and to monitor the changes in volatile compounds correlated with quality decay. The second derivative of the transition function, used to interpolate the PC1 score trend versus the storage time at each temperature, was calculated to estimate the stability time. Results revealed that fruit freshness was maintained for about 5 days at 5.3 \u25e6C, 3 days at 8.6 \u25e6C and 1 day at 15.8 \u25e6C. Moreover, from the time\u2013temperature tolerance chart, a Q10 value of 4.48 was derived. These data were confirmed applying the continuous method: the fruit freshness was maintained for about 5 days at 4 \u25e6C, 2 days at 7.6 \u25e6C and 1 day at 16 \u25e6C. An interesting future development could be an application in-line of the continuous electronic nose method