1,721,034 research outputs found
Determination of biogenic amine profiles in conventional and organic cocoa-based products
No full textCocoa contains a lot of compounds knowing to influence consumers health, as biogenic amines (BAs). Spermine, spermidine, putrescine, histamine, tyramine, -phenylethylamine, cadaverine and serotonine have been determined in several cocoa-based products by LC-UV after derivatization with dansyl-chloride. Once optimized in terms of linearity, recovery percentages, LOD, LOQ and repeatability, the method has been applied to real samples. Total BAs concentration ranged from 5.7 μg g-1 to 79.0 μg g-1 with wide variations depending on the sample. BAs present in all samples were, in decreasing order, HIS (1.9-38.1 μg g-1) and TYR (1.7-31.7 μg g-1), while PUT (0.9-32.7 μg g-1), SPD (1.0-9.7 μg g-1) and SPM (0.6-9.3 μg g-1) were present in most of the samples. CAD, SER and PHE are in few samples at much lower concentrations. Organic samples always contained much lower BAs levels than their conventional counterparts and, generally speaking, the highest BAs amounts has been found in the most processed products
Biogenic amines profile and concentration in commercial milks for infants and young children
No full textCommercial milks for infants and young children (CMIYC) received much attention during last years for their impact on the nutritional status, health and development of the new-born and babies. Among possible contaminants contained in these foods, biogenic amines (BAs) have rarely been determined although they can exert toxic effects in humans if ingested at high concentrations. Spermine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine and cadaverine have been quantified in CMIYC samples by LC-UV after derivatisation with dansyl-chloride. Once optimised in terms of linearity (R 2 ≥ 0.989), recovery percentages (92.9–97.3), LOD (0.2–0.4 μg g −1 or 0.03–0.05 μg mL −1 depending on the samples), LOQ (0.5–1.0 μg g −1 and 0.08–0.13 μg mL −1 depending on the samples) and repeatability (0.1–0.2 intra-day; 0.2–0.4 inter-day), the method has been applied to real samples. Very low total BAs concentrations have been found in reconstituted (1.18–3.12 mg L −1 ) and liquid milks (0.33–2.30 mg L −1 ), with different biogenic amine profiles and distributions. A risk assessment based on the available information regarding Acute Reference Doses of histamine and tyramine, as well as the application of common Biogenic Amine Indexes, showed that none of the analysed samples represented a possible risk for babies, also considering a worst case evaluation. These findings confirmed the strict safety and quality protocols adopted during the production of CMIYC. Chemical compounds studied in this article: Ammonium chloride (PubChem CID: 25517); Cadaverine hydrochloride (PubChem CID: 5351467); Hydrochloridric acid (PubChem CID: 313); Histamine dihydrochloride (PubChem CID: 5818); Phenylethylamine hydrochloride (PubChem CID: 9075); Putrescine dihydrochloride (PubChem CID: 9532); Sodium hydroxide (PubChem CID: 14798); Spermine tetrahydrochloride (PubChem CID: 1103); Spermidine trihydrochloride (PubChem CID: 1102); Tyramine hydrochloride (PubChem CID: 66449)
Molecularly Imprinted Polymers Based On Amidic Functional Monomers For Selective Recognition Of Cholesterol In Aqueous Media
No full textThe aim of this work was to investigate the possibility of employing
amidic functional monomers for the preparation of Molecularly
Imprinted Polymers (MIPs) able to bind selectively cholesterol in aqueous
media. For this purpose, Acrylamide and N,N-Dimethylacrylamide were
employed in order to maximize the hydrogen bound forming both in
pre-polymerization complex and in rebinding experiments which were
performed in polar solvents; in particular, an acetonitrile:water (7:3 v/
v) mixture was employed. The so obtained matrices showed a good
binding capacity towards the template molecule, they bound, indeed,
much more cholesterol than the corresponding non-imprinted ones.
Finally, the polymers affinity for cholesterol and its selectivity using two
steroids quite similar to cholesterol such as progesterone and
hydrocortisone. The synthesized materials, showed a good selectivity,
because they recognised less effectively the two analogues
Chemometric analysis for discrimination of extra virgin olive oils from whole and stoned olive pastes
Full text linkChemometric discrimination of extra virgin olive oils (EVOO) from whole and stoned olive pastes was carried out by using Fourier transform infrared (FTIR) data and partial least squares-discriminant analysis (PLS1-DA) approach. Four Italian commercial EVOO brands, all in both whole and stoned version, were considered in this study. The adopted chemometric methodologies were able to describe the different chemical features in phenolic and volatile compounds contained in the two types of oil by using unspecific IR spectral information. Principal component analysis (PCA) was employed in cluster analysis to capture data patterns and to highlight differences between technological processes and EVOO brands. The PLS1-DA algorithm was used as supervised discriminant analysis to identify the different oil extraction procedures. Discriminant analysis was extended to the evaluation of possible adulteration by addition of aliquots of oil from whole paste to the most valuable oil from stoned olives. The statistical parameters from external validation of all the PLS models were very satisfactory, with low root mean square error of prediction (RMSEP) and relative error (RE%)
Temperature-sensitive hydrogels by graft polymerization of chitosan and N-isopropylacrylamide for drug release
No full textThermo-responsive polysaccharidic hydrogels were designed and synthesized by a free radical induced grafting procedure. Chitosan was chosen as biopolymer to impart biocompatibility and biodegradability to the macromolecular systems, while N-isopropylacrylamide (NIPAAm) was selected as co-monomer responsive for the thermo-sensitive properties. Ammonium persulfate was the initiator system and different polymeric networks have been synthesized by modulating the amount of NIPAAm in the polymerization feed. The resulting hydrogels were proposed as drug delivery devices and their performance was evaluated by using Diclofenac sodium salt as a model drug. Hydrogels were carefully characterized by FT-IR spectrophotometry, calorimetric analyses and swelling behavior in a temperature range of 15-45 degrees C. Finally, to verify the suitability of these hydrogels as thermo-responsive devices, the drug release profiles were studied performing in vitro experiments around the swelling-shrinking transition temperatures of the macromolecular systems
Food Applications of Active and Intelligent Packaging: Legal Issues and Safety Concerns
No full textUnlike traditional packaging, which must be totally inert, active packaging is designed to interact with the contents and/or the surrounding environment. Active packaging systems are successfully used to increase the shelf life of processed foods and can be categorized into adsorbing and releasing systems. Intelligent packaging is characterized by its ability to monitor the condition of packaged food or the environment by providing information about different factors during transportation and storage including time-temperature indicators, gas detectors, and freshness and/or ripening indicators. At the same time, advances in nanotechnology and the improvement of nanomaterials will enable the development of better and new active and intelligent packaging. Until 2004 in Europe there was a legislative lack for these kinds of packaging decreasing their penetration in the EU market. To face the problem Regulation 1935/2004/EC and more specifically Regulation 450/2009/EC set new legal basis for their correct use, safety and marketing
Smart Bandage Based on Molecularly Imprinted Polymers (MIPs) for Diclofenac Controlled Release
Full text linkThe aim of the present study was the development of a “smart bandage” for the topical administration of diclofenac, in the treatment of localized painful and inflammatory conditions, incorporating Molecularly Imprinted Polymers (MIPs) for the controlled release of this
anti-inflammatory drug. For this purpose, MIP spherical particles were synthesized by precipitation polymerization, loaded with the therapeutic agent and incorporated into the bandage surface. Batch adsorption binding studies were performed to investigate the adsorption isotherms and kinetics and the selective recognition abilities of the synthesized MIP. In vitro diffusion studies were also carried out using Franz cells and the obtained results were reported as percentage of the diffused dose, cumulative amount of diffused drug, steady-state drug flux and permeability coefficient. Moreover, the biocompatibility of the developed device was evaluated using the EPISKINTM model.
The Scatchard analysis indicated that the prepared MIP is characterized by the presence of specific binding sites for diclofenac, which are not present in the corresponding non-imprinted polymer, and the obtained results confirmed both the ability of the prepared bandage to prolong the drug release and the absence of skin irritation reactions. Therefore, these results support the potential application
of the developed “smart bandage” as topical device for diclofenac sustained release
Imprinted hydrophilicnanospheres as drug delivery systems for 5-fluorouracil sustained release
No full textMolecularly imprinted hydrogel nanospheres as devices for the controlled/sustained release of 5-fluororacil in biological fluidswere synthesized employing one-pot precipitation technique as the polymerization method. Methacrylic acid as a functionalmonomer and ethylene glycole dimethacrylate as a cross-linker were used in polymeric feed. Morphological and hydrophilicproperties were determined by scanning electron microscopy and water content measurement, and recognition and selectivityproperties of spherical molecularly imprinted polymers were compared with the spherical non-imprinted polymers, both inorganic (acetonitrile) and water media. Finally, in vitro release studies were performed in plasma simulating fluids
Antioxidant activity and phenolic content of Mapo Tangelo
No full textThe antioxidant properties of Mapo Tangelo fruit and leaves extracts were investigated. The con-
tent of health-promoting components (total phenolics, flavonoids and ascorbic acid) were evaluat-
ed by spectrophotometric assays. Higher concentrations of total phenolics, flavonoids and ascor-
bic acid were found in peel samples extracted with boiling water, followed by leaves extracted with
boiling ethanol. The radical-scavenging activity of the extracts was evaluated by different in vitro
tests (total antioxidant activity, DPPH, ABTS and β-carotene bleaching tests). The trend observed
for bioactive compounds was confirmed by antioxidant activity assays and good correlation val-
ues were obtained with total phenolics, flavonoids and ascorbic acid
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