1,720,964 research outputs found
Studio di caratterizzazione aromatica dell'uva Falanghina mediante spettrometria di massa (Study of aromatic characterization of Falanghina grapes by mass spectrometric techniques)
No full textMesophilic and psychrotrophic bacteria from meat and their spoilage potential in vitro and in beef
No full textMesophilic and psychrotrophic populations from refrigerated meat were identified in this study, and the spoilage potential of microbial isolates in packaged beef was evaluated by analyzing the release of volatile organic compounds (VOC) by gas chromatography-mass spectrometry (GC/MS). Fifty mesophilic and twentynine psychrotrophic isolates were analyzed by random amplified polymorphic DNA-PCR, and representative strains were identified by 16S rRNA gene sequencing. Carnobacterium maltaromaticum and C. divergens were the species most frequently found in both mesophilic and psychrotrophic populations. Acinetobacter baumannii, Buttiauxella spp. and Serratia spp. were identified among the mesophilic isolates, while Pseudomonas spp. were commonly identified among the psychrotrophs. The isolates were further characterized for their growth at different temperatures and their proteolytic activity in vitro on meat proteins extracts at 7°C. Selected proteolytic strains of Serratia proteamaculans, Pseudomonas fragi, and C. maltaromaticum were used to examine their spoilage potential in situ. Single strains of these species and mixtures of these strains were used to contaminate beef chops that were packed and stored at 7°C. At time intervals up to 1 month, viable counts were determined, and VOC were identified by GC/MS. Generally, the VOC concentrations went to increase during the storage of the contaminated meats, and the profiles of the analyzed meat changed dramatically depending on the contaminating microbial species. About 100 volatiles were identified in the different contaminated samples. Among the detected volatiles, some specific molecules were identified only when the meat was contaminated by a specific microbial species. Compounds such as 2-ethyl-1-hexanol, 2-buten-1-ol, 2-hexyl-1- octanol, 2-nonanone, and 2-ethylhexanal were detectable only for C. maltaromaticum, which also produced the highest number of aldehydes, lactones, and sulfur compounds. The highest number of alcohols and ketons were detected in the headspace of meat samples contaminated by P. fragi, whereas the highest concentrations of some alcohols, such as 1-octen-3-ol, and some esters, such as isoamyl acetate, were produced by S. proteamaculans. In conclusion, different microbial species can contribute to meat spoilage with release of different volatile compounds that concur to the overall quality decrease of spoiling meat
Individuazione di marcatori odorosi del vino Falanghina DOC dei Campi Flegrei e del Taburno
No full textProteomic approaches to study structure, functions and toxicity of legume seeds lectins. Perspectives for the assessment of food quality and safety
No full textLectins are a structurally diverse class of (glyco)proteins which bind mono- and oligosaccharides with high specificity and in a reversible way. For many years, the unique sugar binding properties of plant lectins have been exploited for the development of biochemical tools for glycoprotein isolation and characterisation, and the use of lectins as a glycoprofiling tool has became much more sophisticated with the advent of lectin microarrays, in which a panel of lectins are immobilized on a single chip for glycomic analysis. Among the numerous lectins studied so far, those from legumes represent the largest family. They can be present at relatively high amounts depending on genetic as well as environmental factors, and are accumulated especially in the seeds. For this reason, some lectins as the phytohemagglutinin from the common bean Phaseolus vulgaris constitute a possible risk, since consumption of raw or incorrectly processed beans has been shown to cause outbreaks of gastroenteritis, nausea and diarrhoea. On the other hand, for these anti-nutritional properties, bean extracts enriched in lectins or in lectin-related amylase inhibitors are also finding a growing use as active ingredients of "weight-blockers" in dietetic preparations for obesity treatment. Current methods to determine the lectin levels in foods are based on immunoenzymatic or toxicity tests, which are largely aspecific. Very recently, the availability of proteomic methodologies has allowed to start development and validation of sensitive and specific assays for detecting trace amounts of harmful lectins in either raw or processed foods. In this review, the main aspects of current and perspective applications of mass spectrometry and proteomic technologies to the structural characterisation of legumes are presented, with focus on issues related to detection, identification, and quantification of phytohemagglutinins relevant for their biochemical, immunological and toxicological aspect
La componente aromatica varietale quale marcatore di processo e di conservazione di vini autoctoni campani
No full textMolecular basis of the interaction between proteins of plant origin and proanthocyanidins in a model wine system
No full textA peptidomic approach for monitoring and characterising peptide cyanotoxins produced in Italian lakes by matrix-assisted laser desorption/ionisation and quadrupole time-of-flight mass spectrometry
No full textDioxin-like PCB levels in maternal and umbilical cord sera of people living near dump sites in southern Italy: a pilot study of biomonitoring
No full textThe "Triangle of Death" is an area of southern Italy highly polluted due to the presence of numerous illegal waste sites. To assess whether environmental contamination could produce an increased intake of harmful chemicals, we determined the serum levels of the 12 polychlorinated biphenyls (PCBs) indicated as "dioxin like" by the World Health Organization (WHO) in both maternal blood serum and umbilical cord blood serum of people residing in that area. The study was performed on 32 pregnant women and cord serum of their 32 newborn babies. Maternal serum concentrations ranged from 0.019 to 10.426 ng/mL (mean 1.590 ± 2.002 ng/mL), while umbilical serum concentrations ranged from 0.018 to 16.980 ng/mL (mean 1.858 ± 3.558 ng/mL). To normalize the toxic impact of the different congeners, the levels were expressed as WHO-TEQ, i.e., toxic equivalent concentrations. Total PCB concentrations (ΣPCBs WHO-TEQ 1998) were 0.297 TEQ-ng/mL in maternal serum and 0.663 TEQ-ng/mL in cord blood. These levels are significantly higher not only than those found in subjects resident in other areas but also in comparison to those reported in other published studies. This suggests that the exposure of both pregnant mothers and their fetuses to environmental pollution could produce a high intake of PCBs. The study may be important for the public health authorities to evaluate the level of exposure to environmental pollutants in human residents in the Triangle of Death
Bound fatty acids modulate the sensitivity of bovine β-lactoglobulin to chemical and physical denaturation
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