224 research outputs found

    Optimization of the appearance quality in CO2 processed ready-to-eat carrots through image analysis

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    A high-pressure CO2 process applied to ready-to-eat food products guarantees an increase of both their microbial safety and shelf-life. However, the treatment often produces unwanted changes in the visual appearance of products depending on the adopted process conditions. Accordingly, the alteration of the visual appearance influences consumers’ perception and acceptability. This study aims at identifying the optimal treatment conditions in terms of visual appearance by using an artificial vision system. The developed methodology was applied to fresh-cut carrots (Daucus carota) as the test product. The results showed that carrots packaged in 100% CO2 and subsequently treated at 6 MPa and 40◩C for 15 min maintained an appearance similar to the fresh product for up to 7 days of storage at 4◩C. Mild appearance changes were identified at 7 and 14 days of storage in the processed products. Microbiological analysis performed on the optimal treatment condition showed the microbiological stability of the samples up to 14 days of storage at 4◩C. The artificial vision system, successfully applied to the CO2 pasteurization process, can easily be applied to any food process involving changes in the appearance of any food product

    Explaining Africa’s public consumption procyclicality : revisiting old evidence

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    This paper compiles a novel dataset of time-varying measures of government consumption cyclicality for a panel of 46 African economies between 1960 and 2014. Government consumption has, generally, been highly procyclical over time in this group of countries. However, sample averages hide serious heterogeneity across countries with the majority of them showing procyclical behavior despite some positive signs of graduation from the “procyclicality trap” in a few cases. By means of weighted least squares regressions, we find that more developed African economies tend to have a smaller degree of government consumption procyclicality. Countries with higher social fragmentation and those are more reliant on foreign aid inflows tend to have a more procyclical government consumption policy. Better governance promotes counter- cyclical fiscal policy whileincreased democracy dampens it. Finally, some fiscal rules are important in curbing the procyclical behavior of government consumption.info:eu-repo/semantics/publishedVersio

    Financial sustainability and profitability of supercritical CO2 pasteurization of liquid products: A case study

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    This work presents an analysis of a supercritical CO2 (SC-CO2) pasteurization process, focusing on the financial and economic parameters that make the process sustainable at an industrial level. A small company processing 5,000,000 bottles of apple juice per year has been chosen as a case study. Investment and operating costs have been estimated based on data collected from the market and the relevant economic literature. The financial sustainability assessment was performed through the Discounted Cash Flow methodology, proving that SC-CO2 pasteurization is profitable on a 10-year horizon. The Net Present Value is strictly positive and the Internal Rate of Return higher than the cost of funding. The sensitivity analysis shows the robustness of this study to possible changes in the model parameters. Overall, this work demonstrates SC-CO2 pasteurization to be profitable and, considering the current growth of the high-nutritional value fruit juice market, it suggests positive financial returns for both incumbents and new entrants

    Supercritical CO2 for the drying and microbial inactivation of apple's slices

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    Supercritical CO2 (Sc-CO2) drying has been recognized as a promising low temperature drying technique for food products. In this regard, this work focuses on the feasibility of Sc-CO2 drying of apple’s slices: both the microbiological stability and mechanical behavior of the test product after the process have been investigated in dependence from different process parameters, namely drying time, pressurization time, and depressurization time. The microbiological stability was determined for both inoculated pathogenic bacteria (Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes) and naturally present microorganisms (yeasts and molds, mesophilic bacteria and spores and Enterobacteriaceae). Results demonstrated a complete inactivation of pathogenic bacteria under the detection limit (<1 CFU/g) just after the pressurization (10 min) and depressurization (20 min) phases. After the same steps, a strong reduction of vegetative bacteria and yeasts and molds was also observed in comparison with air drying and freeze drying samples. As regards the mechanical behavior, the Young Modulus, measured before and after the CO2 processes to provide a measurement of samples’ stiffness, resulted dependent from the final water activity, but independent from the length of pressurization and depressurization phases at longer drying time. Overall, these results are promising to foster the development of the technology at industrial level

    Supercritical CO2 drying of food matrices

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    [EN] This work explore the use of supercritical CO2 drying as alternative technique for the obtainment of pasteurized and high quality dried product. Several tests were conducted on animal, vegetable and fruit matrixes in order to investigate the effectiveness of SC-CO2 drying process at different process conditions. Design of experiment was performed to find the optimal process conditions for vegetable and fruit matrices, using the final water activity of the products as key indicator for the drying efficiency. The inactivation of naturally present microorganisms and inoculated pathogens demonstrated the capability of SC-CO2 drying process to assure a safe product. Moreover, retention of nutrients was compared with conventional drying methods. Results suggest that supercritical drying is a promising alternative technology for food drying.The research leading to these results received funding from the European Community’s Horizon 2020, Call H2020-SFS-2014-2 “Future Food” project and from the Progetto Strategico di Dipartimento SID of the Department of Industrial Engineering (University of Padua). M.T. and G.P. thank Regione Veneto that supported their fellowship through the grant FSE.Zambon, A.; Vizzotto, TM.; Morbiato, G.; Toffoletto, M.; Poloniato, G.; Dall’acqua, S.; De Bernard, M.... (2018). Supercritical CO2 drying of food matrices. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politùcnica de Valùncia. 17-23. https://doi.org/10.4995/IDS2018.2018.7753OCS172

    Effect of hyperbaric stress on yeast morphology: Study by automated image analysis

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    The effects of hyperbaric stress on the morphology of Saccharomyces cerevisiae were studied in batch cultures under pressures between 0.1 MPa and 0.6 MPa and different gas compositions (air, oxygen, nitrogen or carbon dioxide), covering aerobic and anaerobic conditions. A method using automatic image analysis for classification of S. cerevisiae cells based on their morphology was developed and applied to experimental data. Information on cell size distribution and bud formation throughout the cell cycle is reported. The results show that the effect of pressure on cell activity strongly depends on the nature of the gas used for pressurization. While nitrogen and air to a maximum of 0.6 MPa of pressure were innocuous to yeast, oxygen and carbon dioxide pressure caused cell inactivation, which was confirmed by the reduction of bud cells with time. Moreover, a decrease in the average cell size was found for cells exposed for 7.5 h to 0.6 MPa CO2.CAPES and CNPq (Brazil). Fundação para a CiĂȘncia e Tecnologia (Portugal)

    Preservation over time of dried acellular esophageal matrix

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    Preservation of acellular matrices represents a big challenge for the improvement of tissue engineering. In this work, a new method to preserve over time a decellularized esophageal scaffolds was explored. Dried and sterile acellular esophagi were obtained with a combined treatment of ethanol and a subsequent supercritical CO2 drying. Preservation of the extracellular matrix architecture, collagen content, and mechanical properties up to 6 months demonstrated the efficiency of the methodology with implications in natural scaffold storage. In vitro support of mesenchymal stem cells showed a promising indication to the further use of the technology in pre-clinical and clinical application

    Dry acellular oesophageal matrix prepared by supercritical carbon dioxide

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    The research leading to these results received funding from Cassa di Risparmio di Trento e Rovereto (CaRiTRo) within the research project “Supercritical decellularization of engineered tissues for clinical application”, biomedical science section, 2013. PDC is supported by NIHR Professorship and the Catapult Cell Therapy, UK. NMP is supported by the European Research Council (ERC StG Ideas 2011 BIHSNAM no. 279985 on ‘Bio-Inspired hierarchical super-nanomaterials’, ERC PoC 2013 KNOTOUGH no. 632277 on ‘Super-tough knotted fibres’, ERC PoC 2015 SILKENE no. 693670 on ’Bionic silk with graphene or other nanomaterials spun by silkworms’) and by the European Commission under the Graphene Flagship (WP14 ‘Polymer Composites’, no. 696656). NE thanks Lorenza Lazzari for the donation of BM-MSCs from the Cell Factory Bank (Milan-Italy)
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