345 research outputs found

    Short communication: Relationships between milk quality and acidification in the production of table Mozzarella without starters.

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    The effect of some quality parameters of the milk (refrigeration time, pH, protein, and fat/protein ratio) on the extent of acidification in the production technology of table Mozzarella without starters was investigated. A screening phase carried out at the laboratory level demonstrated that variations of the milk characteristics require different levels of acidification to keep constant the quality of the cheese. The elaboration of the data collected throughout the successive experimentation on industrial scale allowed us to find a mathematical model to describe the relationships between the pH of the curd at stretching time and the milk characteristics, of which the protein concentration and the refrigeration time play the main roles

    Cheese ripening in nonconventional conditions: A multiparameter study applied to Protected Geographical Indication Canestrato di Moliterno cheese

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    A multiparameter study was performed to evaluate the effect of fondaco, a traditional ripening cellar without any artificial temperature and relative humidity control, on the chemical, microbiological, and sensory characteristics of Protected Geographical Indication Canestrato di Moliterno cheese. Ripening in such a nonconventional environment was associated with lower counts of lactococci, lactobacilli, and total viable bacteria, and higher presence of enterococci, in comparison with ripening in a controlled maturation room. Moreover, fondaco cheese underwent accelerated maturation, as demonstrated by faster casein degradation, greater accumulation of free AA, and higher formation of volatile organic compounds. Secondary proteolysis, as assessed by liquid chromatography-mass spectrometry of free AA and low molecular weight peptides, did not show any qualitative difference among cheeses, but fondaco samples evidenced an advanced level of peptidolysis. On the other hand, significant qualitative differences were observed in the free fatty acid profiles and in the sensory characteristics. Principal component analysis showed a clear separation of the fondaco and control cheeses, indicating that ripening in the natural room conferred unique sensory features to the product

    Volatiles and acceptability of liqueurs from kumquat and grapefruit

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    The aim of this work was to produce liqueurs from "minor" citrus fruits, such as kumquat and grapefruit, characterize their volatile fraction and evaluate their acceptability by a consumer test. A limoncello sample (LP) was produced under the same conditions and used for comparison. All the new liqueurs were found to be richer in limonene and poorer in oxygenated compounds than the LP. The volatile fraction was mostly represented (85%) by limonene in grapefruit liqueur. Liqueur from kumquat peel (KP) was the richest in volatile compounds, whereas the one from kumquat whole fruit (KWF) was the poorest. This latter also had the particular feature to be the richest in sesquiterpene alcohols. Octanal and decanal, and two acetals deriving from these aldehydes (1,1-diethoxyoctane and 1,1-diethoxydecane) were most prevalent in KP and LP. The consumer test showed that all liqueurs were judged to be acceptable. Nevertheless, limoncello remained the most preferred, while the KWF liqueur obtained the best flavour score in the group of minor citrus fruits

    A Least-Square Model to Estimate Historical Percentages of Itinerant General Aviation Operations by Aircraft Types and Flight Rules at an Airport

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    Historical airport-level General Aviation (GA) activity plays an important role in airport managerial and operational decision-making processes. We developed a model to estimate historical percentages of itinerant GA operations by four aircraft types and two flight rules. The model is formulated as a least-square optimization model and can be applied to both towered and nontowered airports. We applied the model to airports in the Terminal Area Forecast and compared model estimates with the observed statistics. This study provides a method that could be used in the decision-making processes that require detailed historical GA operations. Document type: Articl

    Biochemical patterns in ovine cheese: influence of probiotic strains.

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    This study was undertaken to evaluate the effect of lamb rennet paste containing probiotic strains on proteolysis, lipolysis, and glycolysis of ovine cheese manufactured with starter cultures. Cheeses included control cheese made with rennet paste, cheese made with rennet paste containing Lactobacillus acidophilus culture (LA-5), and cheese made with rennet paste containing a mix of Bifidobacterium lactis (BB-12) and Bifidobacterium longum (BB-46). Cheeses were sampled at 1, 7, 15, and 30 d of ripening. Starter cultures coupled with probiotics strains contained in rennet paste affected the acidification and coagulation phases leading to the lowest pH in curd and cheese containing probiotics during ripening. As consequence, maturing cheese profiles were different among cheese treatments. Cheeses produced using rennet paste containing probiotics displayed higher percentages of alpha(S1)-I-casein fraction than traditional cheese up to 15 d of ripening. This result could be an outcome of the greater hydrolysis of alpha-casein fraction, attributed to higher activity of the residual chymosin. Further evidence for this trend is available in chromatograms of water-soluble nitrogen fractions, which indicated a more complex profile in cheeses made using lamb paste containing probiotics versus traditional cheese. Differences can be observed for the peaks eluted in the highly hydrophobic zone being higher in cheeses containing probiotics. The proteolytic activity of probiotic bacteria led to increased accumulation of free amino acids. Their concentrations in cheese made with rennet paste containing Lb. acidophilus culture and cheese made with rennet paste containing a mix of B. lactis and B. longum were approximately 2.5 and 3.0 times higher, respectively, than in traditional cheese. Principal component analysis showed a more intense lipolysis in terms of both free fatty acids and conjugated linoleic acid content in probiotic cheeses; in particular, the lipolytic pattern of cheeses containing Lb. acidophilus is distinguished from the other cheeses on the basis of highest content of health-promoting molecules. The metabolic activity of the cheese microflora was also monitored by measuring acetic, lactic, and citric acids during cheese ripening. Cheese acceptability was expressed for color, smell, taste, and texture perceived during cheese consumption. Use of probiotics in trial cheeses did not adversely affect preference or acceptability; in fact, panelists scored probiotic cheeses higher in preference over traditional cheese, albeit not significantly

    Clinical impact of routine angiographic follow-up after percutaneous coronary interventions on unprotected left main

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    Background: Patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) on unprotected left main (ULM) represent a complex subset. The role of routine coronary angiography at follow up in this subset remains debated. Methods: At the documented center, all patients undergoing successful PCI on ULM lesions performing angiographic follow-up is suggested, but adherence to such a recommendation is inhomogeneous. Consecutive patients undergoing DES PCI on ULM were enrolled and experienced no adverse events during the first 6 months. Patients were then allocated to two groups: those undergoing routine control angiography (CA) and those undergoing clinical follow-up (CF). Primary endpoint was major adverse cardiac events (MACE) defined as cardiac death, myocardial infarction and urgent repeat target vessel revascularization. Results: A total of 190 patients underwent successful DES implantation on ULM and the study population was without early events. CA was performed at 6 months after the index procedure in 91 (48%) patients. After 35 \ub1 21 months, MACE rates were significantly more common in the CF group as compared with the CA group (16.2% vs. 4.3%, p = 0.009). At multivariable analysis, CA was associated with reduced MACE risk (HR 0.13, 95% CI 0.1\u20130.7, p = 0.028). Of note, this was mainly driven by higher cardiac death rate in those undergoing CF than in those undergoing CA (p = 0.01). Conclusions: CA after complex PCI, such as ULM PCI, is associated with reduced MACE. Such an observation calls for appropriately designed randomized trials

    The effect of in situ produced dextran on flavour and texture perception of wholegrain sorghum bread

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    This study evaluated the effects of dextran produced in situ by Weissella confusa A16 on the flavour and texture perception of wholegrain sorghum bread containing 50% of wheat flour. Descriptive sensory profiling revealed that sorghum sourdough bread containing in situ produced dextran (0.56% bread weight) was more elastic, foldable, moist, cohesive, soft, flexible, and smooth compared to control sorghum sourdough or native sorghum breads (p Peer reviewe

    Clinical impact of routine angiographic follow-up after percutaneous coronary interventions on unprotected left main

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    Background: Patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) on unprotected left main (ULM) represent a complex subset. The role of routine coronary angiography at follow up in this subset remains debated. Methods: At the documented center, all patients undergoing successful PCI on ULM lesions performing angiographic follow-up is suggested, but adherence to such a recommendation is inhomogeneous. Consecutive patients undergoing DES PCI on ULM were enrolled and experienced no adverse events during the first 6 months. Patients were then allocated to two groups: those undergoing routine control angiography (CA) and those undergoing clinical follow-up (CF). Primary endpoint was major adverse cardiac events (MACE) defined as cardiac death, myocardial infarction and urgent repeat target vessel revascularization. Results: A total of 190 patients underwent successful DES implantation on ULM and the study population was without early events. CA was performed at 6 months after the index procedure in 91 (48%) patients. After 35 ± 21 months, MACE rates were significantly more common in the CF group as compared with the CA group (16.2% vs. 4.3%, p = 0.009). At multivariable analysis, CA was associated with reduced MACE risk (HR 0.13, 95% CI 0.1–0.7, p = 0.028). Of note, this was mainly driven by higher cardiac death rate in those undergoing CF than in those undergoing CA (p = 0.01). Conclusions: CA after complex PCI, such as ULM PCI, is associated with reduced MACE. Such an observation calls for appropriately designed randomized trials

    NAS Demand Predictions, Transportation Systems Analysis Model (TSAM) Compared with Other Forecasts

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    The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These resulting demand scenarios can be incorporated into future flight schedules, therefore providing a quantifiable demand for flights in the NAS for a range of futures. In addition, new future airline business scenarios are investigated that illustrate when direct flights can replace connecting flights and larger aircraft can be substituted, only when justified by demand

    Projecting Future Scheduled Airline Demand, Schedules and NGATS Benefits Using TSAM

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    The Transportation Systems Analysis Model (TSAM) developed by Virginia Tech s Air Transportation Systems Lab and NASA Langley can provide detailed analysis of the effects on the demand for air travel of a full range of NASA and FAA aviation projects. TSAM has been used to project the passenger demand for very light jet (VLJ) air taxi service, scheduled airline demand growth and future schedules, Next Generation Air Transportation System (NGATS) benefits, and future passenger revenues for the Airport and Airway Trust Fund. TSAM can project the resulting demand when new vehicles and/or technology is inserted into the long distance (100 or more miles one-way) transportation system, as well as, changes in demand as a result of fare yield increases or decreases, airport transit times, scheduled flight times, ticket taxes, reductions or increases in flight delays, and so on. TSAM models all long distance travel in the contiguous U.S. and determines the mode choice of the traveler based on detailed trip costs, travel time, schedule frequency, purpose of the trip (business or non-business), and household income level of the traveler. Demand is modeled at the county level, with an airport choice module providing up to three airports as part of the mode choice. Future enplanements at airports can be projected for different scenarios. A Fratar algorithm and a schedule generator are applied to generate future flight schedules. This paper presents the application of TSAM to modeling future scheduled air passenger demand and resulting airline schedules, the impact of NGATS goals and objectives on passenger demand, along with projections for passenger fee receipts for several scenarios for the FAA Airport and Airway Trust Fund
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