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The influence of the olive oil processing steps [paste malaxation (PM), decanter centrifugation (DC), and vertical centrifugation (VC)] on the dissolved oxygen (DO) concentration in virgin olive oil (VOO) right after production was investigated at industrial plant scale for two successive years. The influence of this parameter on quality decay during shelf life, assessed by peroxide value (PV) analysis, was also monitored. The VC step showed the higher oxygenation effect (50% increase in comparison to the control), and a good linear regression (r 2 = 0.83) was found between the initial DO concentration and the PV after 2 days. An 18-months shelf life test, performed on VOO sampled before and after the VC, indicated the slowest decay kinetics in the oils with the lower initial DO concentration, i.e. the non-centrifuged oils.

The effect of blanketing with CO2, naturally evolved during malaxation of olive pastes, on the quality of virgin olive oil was investigated at lab-scale. The O2 depletion was monitored along with CO2 emission to confirm the previously hypothesized accelerated respiration. Malaxation experiments were conducted for 180 min both in sealed (SC) and in the traditional open-to-air conditions to ascertain whether the oil quality was affected by O2 concentration as afforded by CO2 blanketing. The quality of olive oils obtained at different time intervals was monitored by total acidity, peroxide value (PV), specific extinction coefficients K232 and K270, total chlorophyll and total hydrophilic phenols, and HPLC hydrophilic phenols profile. A rapid decrease in oxygen concentration and a simultaneous increase in CO2 concentration were recorded, confirming the accelerated respiration. The oil produced in SC showed a lower PV and K232 coefficient and a higher chlorophyll (10–17 mg/kg) and hydrophilic phenols (110 mg/kg) concentration. No differences in total acidity and K270 coefficient were observed. The hydrophilic phenols profile indicated that, at least for the Frantoio cultivar and an advanced ripeness state, the maximal extraction is generally achieved already after 20 min. Most of the individual hydrophilic phenols have higher concentrations (up to 50%) in SC.

The emission of carbon dioxide (CO2) from olive paste during malaxation was investigated in a lab experiment using a hermetically sealed malaxation chamber. A rapid increase in the concentration of CO2 during malaxation was observed, with an average increase of 32 ml/(l min) for the initial 5 min. Then, the emission progressively decreased to a mean rate of 1.1 ml/(l min). This was probably the result of an initial acceleration in respiration followed by the gradual onset of fermentation processes as ambient oxygen was depleted. After malaxation, small amounts of cellular fermentation products (e.g. ethanol and lactic acid) were detected in the wastewater. In order to examine this phenomenon of the inhibition of oxidation due to evolved CO2, malaxation experiments were conducted in both a sealed and an open-air mixing apparatus. The differences in chlorophyll concentration of the resulting oils were then measured. Large amounts of chlorophyll, about twice as much, were found in the oil produced under sealed conditions. This increase in the concentration of chlorophyll resulted from the limited oxidation of the sample by atmospheric oxygen due to the protection of the evolved CO2.

Pre-fermentation cold maceration of must by the direct addition of two cryogens was studied. The experiments were conducted on Sangiovese grape from a typical Chianti vineyard in the year 2001 with two cryogens (solid state carbon dioxide and liquid nitrogen) and at various temperatures (from −5 to +5 °C) in 500-L batches for 48 h. The wines obtained were characterized by chemical analyses and sensory evaluation, and higher quality resulted as seen from the analytical and sensory characteristics with higher extraction of polyphenolic compounds at lower cold maceration temperature. Liquid nitrogen was more effective than solid carbon dioxide at the same temperature. Proportional increase of wine quality with lower cold maceration temperature was observed for solid carbon dioxide. Further investigation is needed to establish the management protocol, a proper engineering of this technique, and to evaluate its economical advantages.

In this note, the problem of state feedback H/sub /spl infin// control for a class of nonlinear systems is considered. The class under study is a generalization of the well-known Lur'e systems. The H/sub /spl infin// problem is addressed via a class of storage functions of the Lur'e-Postnikov type whose integral term is parameterized by a nonlinear scalar function. The related H/sub /spl infin// controllers consist of a linear term, which is designed for the underlying linearized system, plus a nonlinear term which depends on the nonlinear function. A simple geometrical criterion is provided for the characterization of the set of controllers which ensure a given level of L/sub 2/-performance globally. Some guidelines for an effective design of the controller within this set are discussed via two examples.

Olive 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.

The aim of the work was to compare different techniques, in evaluating the phenolic content of an extra-virgin olive oil with varying storage time and storage conditions. A disposable screen-printed sensor (SPE) was coupled with differential pulse voltammetry (DPV) to determine the phenolic fractions after extraction with a glycine buffer; DPV parameters were chosen in order to study the oxidation peak of oleuropein, which was used as reference compound. A calibration curve of oleuropein was performed in glycine buffer 10 mM, pH=2, NaCl 10 mM (D.L.=0.25 ppm oleuropein, RSD=7%). Moreover a tyrosinase based biosensor operating in organic solvent (hexane) was also assembled, using an amperometric oxygen probe as transducer. The calibration curves were realised using flow injection analysis (FIA) with phenol as the substrate (D.L.=4.0 ppm phenol, RSD=2%). Both of these methods are easy to operate, require no extraction (biosensor) or rapid extraction procedure (SPE), and the analysis time is short (min). The results obtained with these two innovative procedures were compared with a classical spectrophotometric assay using Folin–Ciocalteau reagent and HPLC analysis. Other extra-virgin olive oil quality parameters were investigated using classical methods in order to better define the alteration process and results are reported.

Espresso 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.

Recently, several old Italian grain varieties have been reinstated, and the market seems to reward the breads made with these flours. Among such varieties, cultivar Verna appears to be interesting because the regular consumption of bread obtained by this variety and sourdough provides beneficial effects on human health such as the improving of the lipid, inflammatory, and hemorheological profiles. However, flours derived from Verna shows low technological performances. For example, the W value of these flours, obtained with alveoghraphic tests and considered as the commercial standard for the flour “strength” evaluation, is largely inferior than the W values of the commercial flour blends currently used in the bread making process. Moreover, the W values broadly change among the batches of Verna flours, whereas, usually, commercial blends are provided to bakeries with standard technological properties. Hence, these properties of Verna flour could lead to developed or overworked doughs and therefore to breads of worse quality. In addition, the previous mentioned large variability of flours from Verna can affect also the sourdough microbiota. For these reasons the composition and activity of the sourdough microorganisms should be controlled while the mixing process should be able to adapt to the different flour properties. Some works, in literature, report that monitoring the electrical consumption could provide useful information about the dough rheology, and this could be used to monitor the mixing step. In the present work the effect of different mixing times are evaluated on breads made with Verna flour type 2 leavened with sourdough. Tests were carried out at industrial scale in two different days. During the tests the electric consumption was monitored to highlight some features suitable for the mixing phase control. The breads were evaluated in terms of loaf volume measurement, crumb image analysis and losses of moisture content during storage. The results show that the composition of the sourdough microbiota and the mixing time affects the produced bread, especially when it is baked with low technological performance flours. Bread baked with an appropriate mixing time shows higher loaf volumes and lower water losses during storage.

Vertical centrifugation is an important step in continuous virgin olive oil production. It is used to clarify the oil, through the separation of water and suspended solids. Despite its effectiveness, the centrifuge can impair quality. In particular, it requires water to work, which reduces the concentration of minor compounds in the oil, and introduces dissolved oxygen. This paper reports the impact of the use of a vertical centrifuge on olive oil quality, with particular respect to minor compounds. Tests were carried out on two common cultivars (Arbequina and Coratina) 1 month after production and after six months of storage. The vertical centrifuge was found to impair parameters related to oxidation, such as peroxide value and K232. Particularly, the vertical centrifuge was able to increase the peroxide number of about 2 meqO2/kg. In addition, it oxidizes phenols and consequently reduces the ratio of oxidized and nonoxidized forms of secoiridoids. Furthermore, it removes both hydrophobic (i.e., roughly 25 mg/kg of tocopherols was removed) and hydrophilic antioxidants (biophenolic compounds). Phenols are removed as a function of the oil/water partition coefficient. A total phenols decrease of 47 mg/kg in Arbequina and 117 mg/kg in Coratina was due to vertical centrifugation. Finally, the vertical centrifuge oxidizes the oils and led to the detection of the rancid defect after six months of storage by an olive oil sensory panel group. Practical applications The use of the vertical centrifuge in VOO production is a debated issue. In fact, despite some producers recently started to avoid vertical centrifugation for their top quality products. However, vertical centrifugation is a fundamental step in VOO production, and little is still known on the influence of this centrifuge on VOO quality.

Virgin olive oil vertical centrifugation under inert gas (IVC) was compared with conventional vertical centrifugation in contact with air (CVC). IVC gives a strong reduction of the oil oxygenation in terms of reduced dissolved oxygen concentration and oxidative indexes (peroxide values and K232). Minor compounds (chlorophyll and total phenols) and volatile compounds were not affected by the treatment. Practical applications: A technical implementation of inertized vertical separators appears a practicable solution to preserve virgin olive oil quality traits. This can be easily implemented both by the mill owner with homemade adjustment of the existing machines and by plant industrial manufacturers.

The problem of estimating the domain of validity of state feedback H/sub /spl infin// controllers for a class of nonlinear systems is considered. Such a class is a generalization of the well-known Lur'e systems. A class of storage functions of the Lur'e-Postnikov type depending on a free scalar parameter is considered. For each value of this parameter, a tight estimation of the validity domain of the H/sub /spl infin// controller corresponding to the storage function is provided in form of a strip in the state space. The analytical expression of such estimation makes it possible to compare the performance of the obtained controllers. In particular, some conditions ensuring that nonlinear controllers guarantee larger validity domain estimations than linear controllers are given.

The environmental impact of new farming practices is compared with that of conventional one. The approach is that of LCA and the assessing procedure is based on two cross-interaction matrices relating system inputs with emissions and impacts. With the aim to allow its application also at farm level by non-expert users, the procedure has been implemented in software that facilitate it use. Furthermore, the definition of standard impact values and a total environmental effects index make it easier to compare different systems and to evaluate the improvement achieved with a new agricultural practice. As an example, the model has been applied to compare the environmental effects generated in the production of sunflower using ecological, integrated and conventional farming techniques. Both Ecological and Integrated technique present lower impact than conventional even if for some specific impact the results are inverted. The application highlights the importance of the functional unit: when environmental effects are referred to the unit of production (ton), the total impact of the integrated technique is higher than the conventional one. Energy and CO2 efficiency are also computed, which are resulted to be good indicators of the overall environmental impact of a cultivation system

The qualitative effects of vertical centrifugation (VC), i.e., the last step of the extra virgin olive oil (EVOO) extraction process, were investigated on an industrial scale by sampling EVOOs before and after VC. Several parameters were determined to evaluate EVOO quality. Vertical centrifugation results in a marked loss of volatile aromatic compounds, whereas only a slightly variation was recorded in the hydrophilic phenols concentration.

International audience; Quando agli degli anni '90 Alberto Nocentini mi suggeri di pubblicare i Vocabula Magistri Gori de Aretio, che passavano per essere uno pei pùi antichi glossari bilingui latino-italiano di tipo semasiologico, né lui né io eravamo conscienti che questo testo era il capostipite di una vera e propria tradizione manoscritta di cui ci sono pervenuti 4 esemplari. Il glossario contenuto nel codice cartaceo BL Harleian 6513, del XV secolo, è l'ultimo che rimane oggi da dare alle stampe.