Donatella Restuccia

Molecularly imprinted polymers for the selective extraction of glycyrrhizic acid from liquorice roots

Abstract A new Molecularly Imprinted Solid Phase Extraction (MISPE) protocol was developed for the selective extraction and purification of glycyrrhizic acid (GL) from liquorice roots. Non-covalent MIP were synthesized using methacrylic acid (MAA), 2-(dimethylamino)ethyl methacrilate (DMAEM) or 2-hydroxyethylmetacrylate (HEMA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. After the evaluation of the selectivity of the GL imprinted polymers, the performance of these materials as Solid Phase Extraction (SPE) sorbents was investigated. MIP having HEMA as functional monomer were found to be able to selectively extract almost 80% of GL content in liquorice roots. The proposed MISPE-HPLC procedure has good precision, thus it can be successfully used for the purification of GL from natural sources.

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.

Polyphenol Conjugates and Human Health: A Perspective Review

In recent years, antioxidants have gained great importance because of their potential use in food, pharmaceutical, and cosmetic industries. This interest is rooted in the cumulative evidence connecting active oxygen and free radicals with numerous human degenerative disorders, such as cardiovascular diseases, cancer, aging, and atherosclerosis. Polyphenols are the major class of antioxidant able to reduce the oxidative damages of lipids, proteins, enzymes, carbohydrates, and DNA in living cells and tissues. Among the realm of polyphenol compounds, polyphenol conjugates have been proposed as innovative materials which, by combining the advantageous properties of both the components, can increase the efficiency of antioxidants and their range of application in nutritional and biomedical fields. This work is an overview of the different class of polyphenol conjugates, which will be analyzed in terms of nutritional and biological properties, showing how these bio-conjugates will positively affect the human health.

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.

Chemometric analysis for discrimination of extra virgin olive oils from whole and stoned olive pastes

Chemometric 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%).

Polyphenols and Their Formulations: Different Strategies to Overcome the Drawbacks Associated with Their Poor Stability and Bioavailability

Natural polyphenols represent a class of compounds that has attracted the interest of many researchers and the general public due to the potential health benefits to humans. Polyphenolic molecules are, indeed, characterized by remarkable biological properties, including antioxidant, anti-inflammatory, antimicrobic, cardioprotective and anticancer, and are able to modulate the activity of enzymes involved in the development of pathological conditions. These abilities suggest their employment in pharmaceutical and nutraceutical fields, but also for anti-aging purposes in cosmetic formulations. Despite these advantages, polyphenols are very sensitive to heat and light and present low water solubility, high rate of metabolism and rapid elimination from the body. All these factors contribute to poor stability and bioavailability that drastically reduce their effectiveness. In the present chapter, we will explore the different strategies employed to prepare polyphenols-based formulations in the aim to overcome the drawbacks associated with their poor stability and bioavailability.

Antioxidant Activity of a Mediterranean Food Product: "Fig Syrup"

In this work, the efficacy of fig syrup, a Mediterranean fig derivative, as a nutraceutical supplement, was demonstrated. Fig syrup is a fruit concentrate used as a common ingredient in the preparation of typical foods, and particularly in cakes. In vitro assays were performed to determine the amount of nutraceutical ingredients, such as phenolic compounds (3.92 mg equivalent of gallic acid per g) and flavonoids (0.35 mg equivalent of catechin per g), while HPLC analyses provided specific information about the composition of antioxidants in the syrup. Furthermore, total antioxidant activity, scavenging properties against DPPH and peroxyl radicals, and the anticholinesterase activity, clearly showed the efficacy of the syrup in preventing damage induced by free radicals and, thus, the applicability of this food derivative as a nutraceutical supplement.

Ciprofloxacin-Collagen Conjugate in the Wound Healing Treatment

The synthesis of a novel functional biomaterial for wound healing treatment was carried out by adopting a free-radical grafting procedure in aqueous media. With this aim, ciprofloxacin (CFX) was covalently incorporated into collagen (T1C) chains employing an ascorbic acid/hydrogen peroxide redox pair as biocompatible initiator system. The covalent insertion of CFX in the polymeric chains was confirmed by FT-IR and UV analyses, while an antibacterial assay demonstrated the activity of the synthesized conjugate against Staphylococcus aureus and Escherichia coli, microorganisms that commonly infect wounds. A catechin blended conjugate was also tested in order to evaluate the ability to influence fibroblast cell growth. The observed antibacterial activity and stimulation of fibroblast growth support the applicability of CFX-T1C conjugate in wound treatment encouraging the healing process.

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