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Dronero, Italy

Belviso S.,University of Turin | Ghirardello D.,University of Turin | Rantsiou K.,University of Turin | Giordano M.,University of Turin | And 8 more authors.
Food Research International | Year: 2014

Wet spent coffee grounds (SCGs) from espresso capsules, a post-consumer organic solid residue produced worldwide, were analysed to determine their chemical and microbiological stability during storage. In particular, the changes in the total phenolic content and antioxidant capacity (based on two free radical scavenging assays and one oxygen radical absorbance assay) were determined on espresso SCG stored in capsules for up to one month at room temperature in a container open to the air. Phenolic compounds were also identified and quantified using high performance liquid chromatography coupled with diode array and mass detectors. Microbiological analysis was performed in parallel on the same stored SCG to determine the total counts and quantify the main microbial groups present during the storage. The total phenolic content, antioxidant capacity and the most important bioactive compounds, such as the total caffeoylquinic acids, were significantly stable during storage for up to one month, while overall microbial stability was observed for up to two weeks of storage. Overall, the recovery of espresso coffee capsules within 15. days could guarantee the maintenance of microbiological stability as well as the content of valuable antioxidant compounds. © 2014 Elsevier Ltd. Source

Yang W.S.,Polytechnic University of Turin | Fuso L.,Tecnogranda SpA | Biamino S.,Polytechnic University of Turin | Vasquez D.,Polytechnic University of Turin | And 3 more authors.
Ceramics International | Year: 2012

Silicon carbide multilayer composites containing short carbon fibres (C sf/SiC) were prepared by tape casting and pressureless sintering. C fibres were dispersed in solvents and then mixed with SiC slurry to make green C sf/SiC tape. Triton X-100 was found to be the best one for Toho Tenax HTC124 fibres (with water soluble coating) among BYK-163, BYK-410, BYK-2150, BYK-9076, BYK-9077 and Triton X-100 dispersants. C sf/SiC multilayer composites containing 5 vol.% fibre (mean fibre length of 3, 4.5, and 6 mm) were obtained. Addition of short C fibres seems to worsen the densification process in the C sf/SiC multilayer composites, whereas anisotropy shrinkage in C sf/SiC was also observed. Open pores size was increased slightly after the addition of C fibre but it decreased with the mean fibre length. Mechanical properties were affected by high residual porosity. The addition of short C fibre has not changed the crack deflection at weak interfaces. C sf/SiC multilayer composites containing longer fibres (4.5 and 6 mm) presented higher elastic modulus, bending strength and Vickers hardness as compared to shorter fibres (3 mm). Improved sintering performance and fibre content are necessary to improve mechanical properties. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Source

Biamino S.,Polytechnic University of Turin | Antonini A.,Polytechnic University of Turin | Eisenmenger-Sittner C.,Vienna University of Technology | Fuso L.,Tecnogranda SpA | And 4 more authors.
Journal of the European Ceramic Society | Year: 2010

Tape casting combined with layer stacking, debinding and sintering proved to be a suitable technique for processing SiC-based multilayers to be used as thermal protection system for space vehicles. In this paper two methods have been evaluated in order to decrease the thermal conductivity through the thickness of the material: the insertion of layers containing a pore forming agent able to leave residual porosity; the deposition of an external insulating coating made of yttria-partially stabilized zirconia (YPSZ). Both techniques contribute to the reduction of thermal conductivity. The insertion into the multilayered structure of porous layers with a high level of residual porosity halves the thermal conductivity but 25% decrease in bending strength is observed. The fracture surface however shows that highly porous layers activates crack deflection mechanism, increasing fracture energy. The use of an YPSZ coating allows for a less evident reduction of thermal conductivity (from 102 to 75. W/(m. K) at room temperature) but good mechanical properties are maintained (340. MPa bending strength). © 2010 Elsevier Ltd. Source

Pignata C.,University of Turin | D'Angelo D.,Environment Park S.p.A. | Basso D.,Tecnogranda SpA | Cavallero M.C.,Tecnogranda SpA | And 4 more authors.
Journal of Applied Microbiology | Year: 2014

Aim: The aim of this study was to investigate the effect of plasma-enhanced chemical vapour deposition (PECVD) treatment on selected bacteria and spores and to contribute to the understanding of the synergistic effect of UV-directed plasma. Methods and Results: The experiments were conducted on pure cultures of Aspergillus brasiliensis and Escherichia coli and on naturally contaminated pistachios that were exposed to pure oxygen-, pure argon- and to a mixture of oxygen-argon-generated plasma for different treatment times and at different micro-organism concentrations. Optical emission spectroscopy (OES) measurements were performed to observe the active species in the plasma. After exposure, the effectiveness of decontamination was assessed through microbiological techniques by calculating the growth reduction on a logarithmic scale. A treatment time of 30 min resulted in a 3·5 log reduction of A. brasiliensis using pure oxygen or argon, while treatment times of 5 min, 1 min and 15 s resulted in a 5·4 log reduction using a mixture of argon and oxygen (10 : 1 v/v). Treatment times of 1 min and 30 s resulted in a 4 log reduction of E. coli with oxygen and argon, respectively, which led to a complete elimination of the micro-organisms. Two-log reductions of fungi were achieved for pistachios after a treatment time of 1 min. Conclusions: These results suggest that this newly designed plasma reactor offers good potential applications for the reduction in micro-organisms on heat-sensitive materials, such as foods. The plasma that was generated with Ar/O2 was more effective than that which was generated with pure oxygen and pure argon. Significance and Impact of the Study: An improvement in the knowledge about PECVD mechanisms was acquired from the chemical and biological points of view, and the suitability of the method for treating dry food surfaces was demonstrated. © 2014 The Society for Applied Microbiology. Source

Cavallero M.C.,Tecnogranda SpA
Journal of the Science of Food and Agriculture | Year: 2015

BACKGROUND: Hazelnut skin is the perisperm of the hazelnut kernel. It is separated from the kernel during the roasting process and is normally discarded. Recent studies have reported that hazelnut skin is a rich source of dietary fibre as well as of natural antioxidants owing to the presence of phenolic compounds. The aim of this study was to assess the use of hazelnut skins obtained from different cultivars for enhancing the nutritional value of fresh egg pasta. RESULTS: Skins obtained from roasted hazelnuts of four different varieties were used at three concentrations as a flour replacement in fresh egg pasta. Hazelnut skin concentration significantly influenced all evaluated physicochemical parameters as well as consumers' appreciation for the pasta, but significant differences were also observed between the four varieties. Although pasta produced with 10 and 15% hazelnut skin displayed the highest content of polyphenolic compounds and antioxidant activity in vitro, pasta containing 5% Tombul hazelnut skin showed maximum consumer preference. CONCLUSION: The results obtained in the present study highlighted that it is possible to use hazelnut skin in fresh pasta production to obtain a fortified food with high fibre content and antioxidant activity. The characteristics of the resulting pasta were strictly correlated with the hazelnut variety used for skin production and, of course, with the percentage of skin that was added. © 2014 Society of Chemical Industry. Source

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