U. Gianfranco Spizzirri

Grafted thermo-responsive gelatin microspheres as delivery systems in triggered drug release

In this paper, a novel class of microspheric hydrogels was synthesized by grafting of N-isopropyacrylamide (NIPAAm) with gelatin. The possibility of inserting commercial gelatin in a crosslinked structure bearing thermo-sensitive moieties, by radical process, represents an interesting innovation that significantly improves the device performance, opening new applications in biomedical and pharmaceutical fields. This synthetic approach allows a modification of the polymeric network composition, producing hydrogels with suitable physico-chemical properties and a transition temperature higher than NIPAAm homopolymers. The incorporation of monomers into the network was confirmed by infrared spectroscopy, and the composition of the polymerization feed was found to strictly influence the network density and the shape of hydrogels. Thermal analyses showed negative thermo-responsive behaviour with shrinking/swelling transition values in the temperature range 34.6-34.8 degrees C, according to the amount of the hydrophilic portions in the network. In order to test the preformed materials as drug carriers, diclofenac sodium salt was loaded into the spherical microparticles. After the determination of the drug entrapment percent, drug release profiles in media at different temperature were analysed. By using semi-empirical equations, the release mechanism was extensively studied and the diffusional contribution was evaluated.

A new method for the determination of biogenic amines in cheese by LC with evaporative light scattering detector

This paper presents a new LC method with evaporative light scattering detection (ELSD), for the separation and determination of the biogenic amines (histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine) which are commonly present in cheese, as their presence and relative amounts give useful information about freshness, level of maturing, quality of storage and cheese authentication. The LC-ELSD method is validated by comparison of the results with those obtained through LC-UV determination, based on a pre-column dansyl chloride derivatisation step. The obtained data demonstrate that both methods can be interchangeably used for biogenic amines determination in cheese. The new LC-ELSD method shows good precision and permits to achieve, for standard solutions, limit of detection (LOD) values ranging from 1.4 to 3.6 mg L(-1) and limit of quantitation (LOQ) values ranging from 3.6 to 9.3 mg L(-1). The whole methodology, comprehensive of the homogenization-extraction process and LC-ELSD analysis, has been applied in the analysis of a typical Calabria (Southern Italy) POD cheese, known as Caciocavallo Silano. The most aboundant amine found was histamine, followed, in decreasing order, by tyramine, spermine, putrescine, β-phenylethylamine and spermidine, for a total amount of 127 mg kg(-1). This value does not represent a possible risk for consumer health, according to the toxicity levels reported in literature and regarded as acceptable.

Determination of Phospholipids in Food Samples

Phospholipids (PLs), the most important class of polar lipids in foods, are ubiquitous compounds because they are the major components of animal and plant cell membranes. Their technological and biological properties therefore make them important in human nutrition. The efficient separation and accurate quantification of PLs can be achieved with high-performance liquid chromatography–evaporative light scattering detection (HPLC-ELSD) because ELSD is a quasi-universal detector for liquid, countercurrent, and supercritical fluid chromatography and can detect any analyte less volatile than the mobile phase. In this article, the principles of ELSD operation (i.e., nebulization of the chromatographic effluent, evaporation of the mobile phase, and measurement of the scattered light) as well as the application of LC-ELSD to determine the amount of PLs in different food matrices are reviewed. Food matrices containing PLs include milk and dairy products, meat, fish, eggs, cereals, and oils. Both the technological aspects and analytical parameters affecting the concentration and quantitative determination of PLs in food matrices are evaluated. In particular, different extraction, purification, and chromatographic conditions were extensively investigated; moreover, wherever possible, the results obtained are reported and compared with other detection methods.

Brewing effect on levels of biogenic amines in different coffee samples as determined by LC-UV.

Eight biogenic amines (spermine, spermidine, putrescine, histamine, tyramine, phenylethylamine, cadaverine and serotonin) were determined by LC-UV after derivatization with dansyl-chloride in both ground coffee and coffee beverages obtained by different methods. In ground coffee, the most relevant amine was PUT, followed by SPD, HIS, TYR, CAD, SPM, PHE, and SER, with the total BAs content decreasing as the roasting degree increased. In coffee brews, the order was PUT, SPM, TYR, CAD, SPD, PHE, HIS, and SER, but at a very low level in comparison with the amount of BAs determined in roasted ground coffee. Beverages prepared by espresso, capsule, and pod machines had the lowest BAs contents, as a result of the thermal and physical stress imposed on ground coffee by these methods, while mocha contained the highest BAs amounts owing to lower pressure and longer brewing time.

Determination of biogenic amine profiles in conventional and organic cocoa-based products

Cocoa contains many compounds such as biogenic amines (BAs), known to influence consumer health. Spermidine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine, cadaverine and serotonine have been found in several cocoa-based products using HPLC with UV detection after derivatisation with dansyl-chloride. Once optimised in terms of linearity, percentage recovery, LOD, LOQ and repeatability, this method was applied to real samples. Total concentrations of BAs ranged from 5.7 to 79.0 µg g−1 with wide variations depending on the type of sample. BAs present in all samples were in decreasing order: histamine (1.9–38.1 µg g−1) and tyramine (1.7–31.7 µg g−1), while putrescine (0.9–32.7 µg g−1), spermidine (1.0–9.7 µg g−1) and spermidine (0.6–9.3 µg g−1) were present in most of the samples. Cadaverine, serotonine and β-phenylethylamine were present in a few samples at much lower concentrations. Organic samples always contained much lower levels of BAs than their conventional counterparts and, generally speaking, the highest amounts of BAs were found in the most processed products. Graphical Abstract

Antioxidative Effectiveness of Environment Friendly Functional Biopolymers for Food Applications

As consumers are demanding polymeric materials more natural, disposable, biodegradable and recyclable, the interest in active food-packaging systems in which the polymer matrix has low environmental impact is growing significantly. To this regard, the insertion of antioxidant molecules onto polysaccharides backbone is an innovative strategy to produce biocompatible species suitable for food-packaging applications. Moreover, free radical grafting is a method which allows the synthesis of antioxidant biomacromolecule without the use of organic solvents or toxic radical initiators. In the present study, quercetin, catechin and gallic acid were bound to chitosan, starch, inulin and alginate using this technique and good antioxidant activity of the conjugates were observed. This can be useful in the optimization of food preservation and to help manufacturers in elaboration of new and sustainable food products and packaging.