Membrane separation technology for the reduction of alcoholic degree of a white model wine

The reduction of the alcoholic degree of a white model wine by means of membrane separation technology was studied in this work. Reverse osmosis and nanofiltration are the most promising processes for the production of wines with low alcohol content, because they can operate at low temperature and thereby preserve the aromatic profile of wine. Assuming that the rejection of the main wine compounds (i.e. acids, sugars and tannins) is very high, the aim of this research was to study the permeation of several characteristic aroma compounds in the white model wine. Permeation was conducted in batch retentate-recycling mode with two reverse osmosis and one nanofiltration membranes previously conditioned with a 12 ml/100 ml aqueous ethanol solution. Aroma compounds were identified by gas chromatography coupled to quadrupolar mass selective spectrometry. A mathematical model allowed calculation of the aroma compound concentrations in the retentate and permeate streams as a function of permeate volume and the concentration of solutes in the diluted final wine at 8 ml/100 ml ethanol concentration.     

Rheological characterization of deacylated/acylated gellan films carrying l-(+)-ascorbic acid

Films developed for supporting l-(+)-ascorbic acid (AA), natural antioxidant for the protection of foods, were rheologically evaluated. A film was formulated by mixing gellan gum with its acylated form to attain a higher AA stability and lower non-enzymatic browning. The polymer mixture allowed obtaining a less rigid film, permitting the usage of a lower proportion of glycerol.Mechanical spectra of films evidenced solid-like materials provided the time scale of the observation was shorter than the lifetime of the physical cross-links involved. There was evidence for a shorter time of relaxation in the films stored at 33.3–57.7% of relative humidity, which influenced small deformation (linear range) measurements.Out of linear viscoelasticity a greater hardening effect was observed for A- and B-films and related to enhanced polymer interactions in gellan based films. Its increase with the moisture content may be a result of macromolecular association. Higher rigidity characterized gellan based films (A- and B-networks) at intermediate deformations, which may also lead to higher softening degree till rupture. A smaller hardening and softening degrees were observed for C- and D-systems. This can be ascribed to spatial hindering in the film network by acylated gellan chains, fact that worsened polymer interactions. Atomic force microscopy images reinforced rheological conclusions.     

Multitoxin extraction and detection of trichothecenes in cereals: an improved LC‐MS/MS approach

BACKGROUND: Many multiresidual methods to evaluate natural occurrence of Fusarium toxins are already reported in the scientific literature but a new rapid, reliable, cost‐efficient and high‐sensitivity method for the simultaneous determination of several fusariotoxins is always welcome. Nivalenol (NIV), deoxynivalenol, fusarenon‐X (FUS‐X), 3‐acetyldeoxynivalenol, diacetoxyscirpenol (DAS), HT‐2 toxin, T‐2 toxin, neosolaniol (NEO), zearalanone and zearalenone (ZON) belong to the most common mycotoxins in food matrix grains, e.g., wheat and maize. The proposed method is a multitoxin analytical method that combines high‐performance liquid chromatography (HPLC), atmospheric pressure chemical ionization (APCI), triple‐quadrupole tandem mass spectrometry (LC‐MS/MS) under the selected reaction monitoring (SRM) mode, and it is focused on the optimization of the sample preparation without the need for any cleanup. RESULTS: Three different methods for sample preparation and for the simultaneous extractions of the above‐mentioned fusariotoxins were tested: two of these were followed by a different cleanup step for comparison, while the extraction method proposed in this work, which uses an 84% (v/v) acetonitrile aqueous solution, sample homogenization and subsequent filtration, was validated without any further cleanup step. CONCLUSION: Calibration curves for all analytes are linear, except DAS, HT‐2 and ZON, over the working range of 10–1000 µg kg^?1. The calibration curve of DAS was linear between 10 and 500 µg kg^?1, although the curves of HT‐2 and ZON were linear in the range 10–250 µg kg^?1. Squared correlation coefficients (R²) were in the range 0.995–0.998 for the all point calibration curves. The lowest limits of detection (LOD) were found for DON and ZAN with 0.5 and 0.2 µg kg^?1, respectively, while the highest LODs were obtained for NIV, FUS‐X and NEO, with 3.3 µg kg^?1 for each toxin. Copyright © 2009 Society of Chemical Industry     

Ascorbate,not urate,modulates the plasma antioxidant capacity after strawberry intake

The consumption of antioxidant-rich foods has already been associated with acute significant increases in plasma total antioxidant capacity (TAC) in humans, but there is no consensus among different literature reports. Furthermore, the acute rise in plasma TAC observed after consumption of several non-berry fruits seems not to be necessarily related to the absorption of dietary antioxidants, such as micronutrients and phenolic substances, but is attributed to the relevant increase of endogenous urate in serum. In this study, we first compared the nutritional quality of strawberry fruits from different genotypes, all cultivated in the same experimental field. Significant genotype-to-genotype differences were observed in the antioxidant capacity and in the vitamin C, folate and phenolic contents of the fruits. Second, in order to investigate the individual effects of the selected strawberry genotypes on the post-prandial plasma antioxidant status in humans, we assessed the acute effects of a single dose of strawberries in healthy subjects. The variation of plasma TAC through the FRAP and TEAC assays, and any eventual changes in ascorbate and urate levels in serum, were measured during the three hours following the strawberry intake. The acute intake of strawberries resulted in a significant increase in plasma FRAP values in all the subjects, independently of the individual TAC baseline levels. Interestingly, the lowest increases in plasma TAC and in serum ascorbate levels were associated with consumption of the nutritionally-poorest cultivars. In addition, significant increases in ascorbate, but not in urate, concentrations were observed in serum. These findings suggested that the fructose-dependent hyperuremic effect, observed after the intake of non-berry fruits, is not responsible for the plasma antioxidant changes following strawberry consumption.     

Volatile phenols in virgin olive oils: Influence of olive variety on their formation during fruits storage

The potential significance as odorants and markers of olive fruits degradation has been recently pointed out for volatile phenols in virgin olive oil (VOO) and related to the appearance of VOO sensory defects. The few studies carried out in order to elucidate the factors affecting their formation in olive fruits or VOOs, indicated that they could be considered as analytical indices of olive fruits degradation during storage, likely reflecting the microbiological activity. In the present study, the effect of the olive variety (‘Arbequina’, ‘Arbosana’ and ‘Leccino’) on the production of volatile phenols during twelve days of storage in closed plastic bags was evaluated. The different resistance of each variety to the microbiological attach was observed during olive fruit storage, and it was reflected by the evolution of guaiacol, 4-ethylphenol and 4-ethylguaiacol, and related to free acidity values. On the contrary, a scarce dependence on the microbial growth or varietal factors was observed for 4-vinyl derivatives, which appeared more directly related to the time of olives storage. The evolution of volatile phenols found certain correspondence in the sensory characteristics of the resulting VOOs, while the rest of VOO chemical quality indices did not show major variations during fruits storage.     

Evaluation of Functional Phytochemicals in Destoned Virgin Olive Oil

Processing destoned olives by means of extracting adjuvants micronised food talc and depolymerising Cytolase 0 enzyme complex have been studied in the present work. This innovative processing technology increased the plant efficiency (amounts of olives processed per hour) by 20%, as well as the nutritional quality of the end product with respect to functional compounds. The oils showed higher contents of biophenols, aromas, and tocopherols. An intense and balanced flavor and a potentially higher stability and endurance to oxidation (shelf-life) was found. Contents of chloroplast pigments (chlorophylls, pheophytins, carotenes, and xanthophylls) appeared to be lower in comparison to conventional processing. The processing aids allowed to increase significantly the oil yields and to reduce the oil percentage in the byproducts. Traceability of the new products was still possible applying chemometric data analysis for discriminating between cultivars.     

Hybrid PVA-xanthan gum hydrogels as nucleus pulposus substitutes

Hybrid hydrogels were synthesized mixing poly(vinyl alcohol) (PVA) and xanthan gum (XG) in different molar ratios and using trisodium trimetaphosphate, as crosslinking agent, to obtain potential nucleus pulposus substitutes. Human Nucleus Pulposus (NP) is a hydrogel-like tissue with peculiar properties, which determine its role in supporting and dissipating spinal loads. Hydrogel obtained mixing PVA and XG in molar ratio 4:1 (PX25) showed mechanical, swelling, and thermal properties, i.e., heat capacity, which make it a good candidate as a potential NP substitute. Preliminary cytotoxicity tests pointed out that the developed materials did not show any signs of cytotoxicity towards NIH3T3 cells.     

Wet Lay-Up Manufactured FRPs for Concrete and Masonry Repair: Influence of Water on the Properties of Composites and on Their Epoxy Components

The assessment of durability of fiber-reinforced polymers (FRPs), used to strengthen masonry or concrete structures, if subjected to weathering is a knotty problem. Environmental factors can have a significant effect on their performance in service. In order to investigate on this aspect, the mechanical behavior of two commercial composites, reinforced with unidirectional carbon and glass fibers, was analyzed after a long-term immersion in distilled water. For comparison purposes, three different commercial epoxy resins, used as primer, putty, or adhesive to manufacture and apply the composites through the wet lay-up technique to the surfaces to strengthen, were subjected to the same treatment. In order to take into account the peculiarities of the three cold-curing epoxy resins, a novel procedure to dry the specimens before the immersion treatment was used. The mechanical tests, performed on the composites before and after their immersion in water, evidenced that this agent has a limited effect only on the in-plane tensile strength of wet lay-up manufactured glass FRP, while the mechanical properties of carbon FRP are substantially unaffected by water. On the other hand, the effect of water on the thermal and mechanical characteristics of the three epoxy resins is quite severe, with significant reductions in the glass transition temperature, stiffness, and strength.     

Novel 3D porous multi-phase composite scaffolds based on PCL,thermoplastic zein and ha prepared via supercritical CO2 foaming for bone regeneration

The aim of this study was the design of novel biodegradable porous scaffolds for bone tissue engineering (bTE) via supercritical CO₂ (scCO₂) foaming process. The porous scaffolds were prepared from a poly(ε-caprolactone)-thermoplastic zein multi-phase blend w/o interdispersed hydroxyapatite particles (HA) and the porous structure achieved via the scCO₂ foaming technology. The control of scaffolds porosity was obtained by modulating materials formulation and foaming temperature (T_F). The scaffolds were subjected to morphological, micro-structural and biodegradation analyses, as well as in vitro biocompatibility tests. Results demonstrated that both HA concentration and T_F significantly affected the micro-structural features of the scaffolds. In particular, scaffolds with porosity and pore size distribution, mechanical properties and biodegradability adequate for bTE were designed and produced by selecting a T_F equal to 100 °C for all the compositions used. The biocompatibility of these scaffolds was assessed in vitro by using osteoblast-like MG63 and human mesenchymal stem cells (hMSCs).