The Evaluation of the Effects of Dietary Vitamin E or Selenium on Lipid Oxidation in Rabbit Hamburgers: Comparing TBARS and Hexanal SPME-GC Analyses

The effects and specificity of dietary supplementation of EconomasETM (EcoE), mainly consisting of organic selenium (0.15 or 0.30 mg/kg feed; Se) or of vitamin E (100 or 200 mg/kg feed; VE), on lipid oxidation were evaluated in rabbit hamburgers during refrigerated storage. Oxidation data obtained by thiobarbituric acid-reactive substances (TBARS) spectrophotometric analysis and solid-phase microextraction (SPME) coupled with gas chromatography (GC) to determine hexanal content were compared. The relationships between oxidation levels, colour and pH and the discriminability of EcoE- or VE-treatment compared with control were also examined. TBARS content decreased in both VE and EcoE groups, while hexanal showed lower values only in the VE100 dietary group. The colour parameters were compatible with acceptable product quality and seemed to parallel the TBARS values up to the second day storage. Both VE and EcoE improved oxidative stability without affecting the sensory properties, but the VE effect appeared to more specifically hamper lipid oxidation, as evidenced by the determination and quantification of hexanal, a specific product of fatty acid peroxidation

In vivo and in vitro effects of selected antioxidants on rabbit meat microbiota

The purpose of this study was to investigate the effect of dietary vitamin E or EconomasE™ supplementation on the growth of several background/pathogenic bacteria on rabbit carcasses and hamburgers during refrigerated storage. For 51days, 270 New Zealand rabbits received either a basal diet, or experimental diets enriched with 100 or 200mg/kg of vitamin E or EconomasE™. The bacteria studied were Salmonella, Listeria monocytogenes, Pseudomonas, Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, plus both mesophilic and psychrotrophic aerobes. The growth of Listeria monocytogenes on contaminated patties was evaluated through a challenge test. The potential protective or antimicrobial effect of vitamin E or EconomasE™ on Listeria monocytogenes or Pseudomonas aeruginosa was assessed in vitro. Diet did not influence the concentrations of bacteria found on rabbit carcasses and developing on hamburgers. Vitamin E (in vivo and in vitro) and EconomasE™ in vivo had a protective antioxidant role, while EconomasE™ in vitro had strong antibacterial activity against Listeria monocytogenes, but not against Pseudomonas aeruginosa

The Italian inter-laboratory study on the detection of Pseudomonas syringae pv. actinide

A severe form of bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), has been detected in all the main areas of cultivation of kiwifruit (Actinidia deliciosa and A. chinensis). Since 2010 several research groups have been assessing methods and procedures to detect and identify Psa, both from symptomatic and symptomless host material. In 2011, a study to compare Psa diagnostic methods was performed with reference to Psa strains and related pathovars, and with plant extracts or DNA obtained from healthy and naturally infected leaves, pollen or wood. The study revealed the strengths and the weaknesses of the assessed methods. The procedure included screening tests for Psa detection and for identification of Psa colonies. The methods assessed were bacterial isolation on generic and semi-selective media, PCR analysis (single, duplex and rep-PCR assay, the latter for identification only). The results highlighted the best performance of semi-selective with respect the generic media; the usefulness of the direct-PCR as screening tests for Psa detection; and the greater specificity of duplex-PCR and sensitivity of simple-PCR. The use of semi-selective medium for isolation and of two PCR-based methods - in parallel - for Psa detection are suggested. Both rep-PCR and duplex-PCR, were found to be specific, and are recommended as an identification test for this pathogen

Evaluation of the prognostic value of impaired renal function on clinical progression in a large cohort of HIV-infected people seen for care in Italy

Whilst renal dysfunction, especially mild impairment (60 die;ve (Icona) Foundation Study collected between January 2000 and February 2014 with at least two creatinine values available. eGFR (CKD-epi) and renal dysfunction defined using a priori cut-offs of 60 (severely impaired) and 90 ml/min/1.73m2 (mildly impaired). Characteristics of patients were described after stratification in these groups and compared using chi-square test (categorical variables) or Kruskal Wallis test comparing median values. Follow-up accrued from baseline up to the date of the CCVD or AIDS related events or death or last available visit. Kaplan Meier curves were used to estimate the cumulative probability of occurrence of the events over time. Adjusted analysis was performed using a proportional hazards Cox regression model. We included 7,385 patients, observed for a median follow-up of 43 months (interquartile range [IQR]: 21-93 months). Over this time, 130 cerebro-cardiovascular events (including 11 deaths due to CCVD) and 311 AIDS-related events (including 45 deaths) were observed. The rate of CCVD events among patients with eGFR >90, 60-89, <60 ml/min, was 2.91 (95% CI 2.30-3.67), 4.63 (95% CI 3.51-6.11) and 11.9 (95% CI 6.19-22.85) per 1,000 PYFU respectively, with an unadjusted hazard ratio (HR) of 4.14 (95%CI 2.07-8.29) for patients with eGFR <60 ml/min and 1.58 (95%CI 1.10-2.27) for eGFR 60-89 compared to those with eGFR ≥90. Of note, these estimates are adjusted for traditional cardiovascular risk factors (e.g. smoking, diabetes, hypertension, dyslipidemia). Incidence of AIDS-related events was 9.51 (95%CI 8.35-10.83), 6.04 (95%CI 4.74-7.71) and 25.0 (95% CI 15.96-39.22) per 1,000 PYFU, among patients with eGFR >90, 60-89, <60 ml/min, respectively, with an unadjusted HR of 2.49 (95%CI 1.56-3.97) for patients with eGFR <60 ml/min and 0.68 (95%CI 0.52-0.90) for eGFR 60-89. The risk of AIDS events was significantly lower in mild renal dysfunction group even after adjustment for HIV-related characteristics. Our data confirm that impaired renal function is an important risk marker for CCVD events in the HIV-population; importantly, even those with mild renal impairment (90<60)&gt

Gli oli essenziali come agenti di controllo biologico delle batteriosi vegetali: il cancro batterico dell’actinidia

In agricoltura, la crescente necessità di limitare l’impiego di sostanze sintetiche per il controllo delle malattie delle piante ha reso sostanze naturali quali gli oli essenziali (OE) sempre più interessanti dal punto di vista applicativo per il minore impatto ambientale e per la sicurezza alimentare riscuotendo grande attenzione anche da parte dei consumatori. In particolare, il controllo delle batteriosi vegetali è tuttora affidato all’impiego di antibiotici, nei Paesi dove è permesso, e di prodotti rameici che tuttavia sono totalmente inefficaci nei confronti dei batteri patogeni endofiti in piante asintomatiche. La necessità di strategie alternative per il controllo e la gestione delle batteriosi, da adottare specialmente nelle coltivazioni biologiche, è sempre più impellente. Recenti studi sull’attività antimicrobica degli OE distillati da piante aromatiche hanno evidenziato il ruolo cruciale svolto dalla comunità microbica endofita biologicamente attiva nel controllo biologico di batteri fitopatogeni. L’ipotesi di somministrare alle piante OE o loro idrolati (Id) per interferire e bloccare la crescita di batteri fitopatogeni potrebbe costituire un importante strumento di controllo biologico. L’attività antimicrobica in vitro ed in planta di OE e Id ottenuti da Monarda didyma e M. fistulosa è stata valutata nei confronti di Pseudomonas syringae pv. actinidiae Takikawa et al. (Psa), batterio fitopatogeno da quarantena che causa il cancro batterico dell’actinidia. Infatti, gli OE distillati da piante di Monarda spp. sono caratterizzati da un elevato contenuto di monoterpeni, come ad esempio il timolo, il carvacrolo ed il loro precursore p-cimene, usati nell’industria alimentare come additivi per preservare gli alimenti. L’efficacia antimicrobica indotta dai trattamenti pre-infezionali con gli Id è molto incoraggiante per l’eventuale applicazione in campo finalizzato al controllo del cancro batterico dell’actinidia. Infatti, la loro composizione chimica è molto diluita rispetto ai corrispondenti OE e quindi l’azione protettiva nei confronti di Psa, senza causare effetti tossici indesiderati osservati in alcuni casi con gli OE, svolge un ruolo critico nella messa a punto di formulati a base di antimicrobici naturali. Le piante officinali, considerate quindi come sorgenti di nuovi agenti antimicrobici mediante l’impiego sia dei loro OE sia dei loro batteri endofiti, stanno offrendo approcci promettenti ed alternativi nel controllo biologico delle malattie batteriche delle piante degni di essere più approfonditamente studiati

Biologia degli alimenti vegetali

Gli appunti non sostituiscono il testo, che resta uno strumento indispensabile per lo studio, ma rappresentano semplicemente una traccia delle lezioni svolte per orientarsi su uno dei testi consigliat

Qualità e Sicurezza degli Alimenti Vegetali

Gli appunti non sostituiscono il materiale bibliografico selezionato, che resta uno strumento indispensabile per lo studio, ma rappresentano semplicemente una traccia delle lezioni svolte per orientarsi su uno dei testi consigliat

Botanica

Gli appunti non sostituiscono il testo, che resta uno strumento indispensabile per lo studio, ma rappresentano semplicemente una traccia delle lezioni svolte per orientarsi su uno dei testi consigliat

Botanica

Gli appunti non sostituiscono il testo, che resta uno strumento indispensabile per lo studio, ma rappresentano semplicemente una traccia delle lezioni svolte per orientarsi su uno dei testi consigliati

Pseudomonas syringae pv. aptata HRP mutants which fail to produce periplasmic oligosaccharides

Periplasmic oligosaccharides, extracted from Pseudomonas syringae pv. aptata and purified by column chromatography, modify the homologous interaction between tobacco leaves and P. syringae pv. tabaci. The osmoregulating oligosaccharides can act as signal molecules to plant cells, but the molecular basis of this function is not known. Genetical analysis of pathogenicity determinants in P. s. pv. aptata strain NCPPB2664 allowed the identification of hrp genes which are essential in governing the ability of the bacteria to cause disease on host plants (such as sugar beet, lettuce), and the ability to induce the hypersensitive response on non-host plants (such as tobacco). The current study addresses whether a correlation between the pathogenicity and the production of oligosaccharides exists. To test the hypothesis that in the early stages of plant-bacteria interactions the hrp genes might be involved in the production of the periplasmic oligosaccharides, the latter has been studied in P. syringae pv. aptata Hrp- mutants