1,721,036 research outputs found
The spent cake from olive oil filtration as biomass feedstock
No full textThe most widespread method for virgin olive oil filtration at industrial scale is the so-called precoat body-feed filtration by means of filter aids, mainly consisting of perlite and cellulose. The residue of the process is a spent filtration cake, which has the potential for upgrading if it is understood in the context of the biorefining concept. Data about the production and composition of the spent cake were collected from an industrial case-study. The potential availability of the spent cake has been estimated both at local scale (the industrial case-study) and at larger scale based on the Spanish context, that is the world leading virgin olive oil producer. The mean percentage composition of the spent cake is 5% oil impurities, 7% cellulose, 28% perlite, 52% oil and 8% water. About 10 g of spent cake are produced per kilogram of virgin olive oil to be processed; while about 316 and 7482 Mg of spent cake could be potentially available for the local and large scale occasion, respectively. Owing to its composition entailing oil and waxes, cellulose and mineral fractions, the spent cake has the potential as feedstock for the emerging biotechnologies and biorefineries
Metodo e apparato per diraspatura e frazionamento qualitativo degli acini da uva raccolta a mano.
No full textStripping of dissolved oxygen from extra virgin olive oil: Effects on oxidation and biophenols
No full textVertical centrifugation is used in virgin olive oil production to remove residual suspended solids and water from the oil, after horizontal centrifugation. Although this process has clear benefits in terms of productivity, it degrades the olive oil. In particular, vertical centrifugation allows oxygen to dissolve into the olive oil. This decreases the antioxidant content and increases oxidation-related parameters in the oils. These negative effects can be partially prevented with the quick removal of oxygen, for example, by the nitrogen stripping technique. This study tests the effect of nitrogen stripping on two mono-cultivar olive oils (Arbequina and Coratina). The effects are evaluated immediately post-production and after 6 months of storage. Nitrogen stripping improved the peroxide value, K232 parameter, and tocopherol and biophenol content. Furthermore, it was found to prevent depletion of secoiridoids and reduce oxidation, measured as a ratio of the oxidized and non-oxidized forms of secoiridoids. Practical applications: The tested technology could be introduced in line with vertical centrifugation, in order to keep the productivity benefits provided by the centrifugation, but limit the negative effects in term of quality. Thus, the removal of dissolved oxygen with the nitrogen stripping technique could improve olive oil quality
Cultural Determinants of Household Saving Behavior
Full text linkRelying on the epidemiological approach, we show that culture is a significant driver of household saving behavior. Second-generation immigrants from countries that put strong emphasis on thrift or wealth accumulation tend to save more in Germany. We confirm these results in data from the United Kingdom. By linking parents to their children, we show that these two cultural components affect the saving behavior of both first-generation immigrants and their children
Competition and the role of group identity
Full text linkThe emergence of competition is a defining aspect of human nature and characterizes many important social environments. However, its relationship with how social groups are formed has received little attention. We design an experiment to analyze how individuals’ willingness to compete is affected by group identity. We find that individuals display substantially stronger competitiveness in within group (ingroup) matchings than in between group (outgroup) matchings or in a control setting where no group identity is induced. We also find that the effect of group identity is stronger for subjects who participated more actively in the team-building task
Addition of a steel pre-filter to improve plate filter-press performance in olive oil filtration
No full textOlive oil is a turbid colloidal dispersion. The most common technique used to clear the oil is filtration. Among filter systems, plate filter-presses are used by small companies because the filters are cheap, and the technique does not impair the sensory and chemical traits of the olive oil. However, plate filter-presses have some disadvantages: their operating capacity is low, they require a lot of man power, and filter sheets trap part of the processed oil. It has been argued in the literature that they can retain minor compounds. Furthermore, there is a cost associated with their disposal. The impact of all of these issues could be reduced by the optimization of filtration cycles. Hence, a new processing arrangement was proposed and tested. This consisted of the insertion of a steel pre-filter into the system, which retained part of the suspension. Consequently, the plate filter-press only retained residual solids and water. The plate filter press with the added pre-filter was able to process about 1.8 times the amount of oil normally processed in a batch. Operative capacity was improved and the amount of oil trapped in the sheets was reduced. Furthermore, the number of the filter sheets required was almost halved, which also halves their purchase and disposal costs. A surface fouling mechanism is seen in the traditional filter press configuration, while in the new configuration particle retention is due to depth fouling. This change in the fouling mechanism demonstrates that the addition of a pre-filtration step leads to the more effective use of filter sheets
Apparato e metodo d’alimentazione d’olio d’oliva in un dispositivo di trattamento, e relativo impianto di produzione.
No full textA new method for Espresso Coffee brewing: Caffè Firenze
No full textEspresso coffee is the most popular choice for Italian coffee consumers. It has been estimated that every day, in the world, over of 50 million of Espresso cups are taken. As a consequence of this success, a large number of devices to make Espresso have been developed. In this scenario, a new device has been recently developed and patented (Eu. Patent 06 023 798.9; US 2010/0034942 A1). This brew method, named “Caffè Firenze”, uses a sealed extraction chamber, where water and gas provides pressure higher than the other extraction methods. Three main parts compose the apparatus: the gas source, the extraction chamber and the heat exchanger. The gas source provides the pressured gas required to raise the pressure of the system. The extraction chamber is made with chrome-brass and accessorized with two heating glow plugs. Many are the factors affecting Espresso quality: it is known that, coffee type, roasting conditions and degree, grinding and storage strongly affect the obtained brew. Also, several studies have been carried out on the effect of the setting parameters on quality, for example water pressure, water temperature, and brew time. Among the characteristics that determine Espresso quality, the main attribute for the visual analysis is, without doubts, the foam, also called “crema”. Indeed, height, aspect, and persistency of foam are features much appreciates by consumers. Two distinguish Espresso foam parameters are the persistency and foam index. Equipping a commercial bar machine with the new designed extraction chamber makes feasible the comparison between the traditional way to brew Espresso and the new device. The comparison was made holding the previous mentioned conditions, and differences were evaluated in terms of physical parameters and aromatic profiles. Caffè Firenze shows pronounced differences compared with traditional Espresso in term of foam-related parameters. Also, the new extraction device produces coffees with higher values of body-related parameters, such density and viscosity. The two kinds of Espressos are perceived different at visual analysis and taste by a panel test
Energetic and economic viability of olive stone recovery as a renewable energy source: A Southern Italy case study
Full text linkThe recovery of olive stone for biofuel purpose is becoming increasingly widespread in olive milling plants. The study looks at the economic and energetic benefits of using a de-stoner machine in a smallto- medium sized oil milling plant. The performance of the olive stone recovery system was evaluated over a full olive oil production season. The energetic viability of the de-stoner was assessed using an energy balance. The break-even point was achieved when about 76 tons of olives had been processed, which is less than the annual production of the mill under study. Similarly, in economic terms, the machine covered its costs after about the half of its technical life
Qualitative effects of the addition of withered grapes to a freshly produced red wine: the traditional governo all'uso toscano practice
Full text linkBackground and Aims: Governo all'uso toscano (GUT) is a traditional winemaking practice where withered grapes are added to a freshly fermented wine. This results in a second alcoholic fermentation and a distinctive wine, in which there is renewed interest. Grape withering is problematic for winemakers, however, both in terms of cost and risks. It is therefore important to determine the minimum amount of withered grapes needed to typify the wine in order to minimise risks and costs. Methods and Results: During the trials, Sangiovese grapes were withered for 2 months in a dedicated room, a ‘fruttaio’, with a resulting mass loss of about 40%. Afterwards, withered grapes (5–20% berry mass/wine mass) were added to a Control wine to reproduce the GUT procedure. The GUT technique significantly changed the chemical profile of the wines. Ethanol, colour intensity and hue increased, while acidity decreased. Malolactic fermentation occurred simultaneously with the second alcoholic fermentation in all GUT wines, but not in the Control wines. The GUT practice significantly changed the volatile profile, including the concentration of several primary grape compounds, such as aromatic alcohols, C6 compounds and terpenoids, and of several fermentation compounds. Conclusion: Under the experimental conditions, the optimal amount of withered grapes added to the base wine was 5%. Significance of the Study: The study described the oenological effects of GUT and the optimisation of the amount of withered grapes required to make a wine with this characteristic winemaking practice clearly recognisable
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