This review focused on the historical, technological, and analytical characteristics of ricotta cheese available in the literature. Ricotta cheese is a typical dairy product that originated from ...Italy, used in the preparation of several traditional dishes, both sweet and salted. The available studies pertaining to ricotta cheese revealed a considerable biodiversity in the production with a large number of varieties produced, whose production varies according to the local uses and customs. The review shows the main chemical and microbial characteristics of the product and also the several parameters that affect the mechanism of the production process and the final characteristics of the product, including the raw materials, the processing methods, the season, the animals' diet, the animals' species, and breeds. Ricotta production can be artisanal or industrial, with differences in the making process. New trends in ricotta cheese production have been developed, with particular attention to the functional effect on human health and the novel technologies applied to extend the shelf-life of the products. Currently, it is not easy to find these new developments in the market, probably related to the cost of production, which is not always bearable by the farms. However, despite the large classification reported and the great interest by the cheese industry, just a few numbers of studies were found for artisanal ricotta productions, which still need to be characterized and studied.
Alkaline phosphatase (ALP) is a native raw-milk enzyme used in many countries as the standard assay for rapidly validating the milk pasteurization process. Due to the increased restrictions on the ...production or import of cheeses produced from unpasteurized milk, ALP activity (<10 mU/g) in cheese was measured as a simple and reliable method to check proper milk pasteurization in cheese for both safety inspection and trading controls. In Sicily, the artisanal cheesemaking of the Protected Denomination of Origin (PDO) semi-hard cheeses made with raw sheep milk, includes the cooking of the curd, after whey separation, in a wooden vat under hot Scotta whey (≥80°C), for 3 to 4 h, and finally is left to cool at ambient temperature. Thus, the temperatures adopted during cheesemaking may inactivate the ALP enzyme. To this purpose, the aim of this study was to demonstrate how different temperatures of Scotta whey (35°C T35, 60°C T60, 70°C T70, 80°C T80, 90°C T90, and 100°C T100) used during the second cooking of Pecorino cheeses after molding for 3 h, influence the ALP activity in fresh and 3-mo aged cheese, both at core and outside. The results highlight that the rate of reduction of ALP was greater with increasing temperature of the second cooking, in particular for T 80°C curd, indicating that the use of Scotta whey >80°C could be a breakpoint able to reduce the ALP activity to values <10 mU/g. Different effects between the core and the outside portions of the experimental cheeses were found, with a decrease in ALP activity more on the outside than in the core portions, in both fresh and 3-mo aged cheeses, for T80, T90, and T100 treatments. Care must be taken in using ALP to control the use of pasteurized milk in the production of PDO cheeses without considering the cheesemaking processes, such as the second cooking, which could be equal to pasteurization, and an adequate interaction of time and temperature can reduce the ALP activity to values comparable with cheeses produced with pasteurized milk.
This paper presents an Optimal Control Problem (OCP) tailored to assess the system performance of a rigid wing Airborne Wind Energy (AWE) pumping system prior to real flight tests. The proposed ...method is validated against experimental data obtained using a small prototype designed by the Dutch company Ampyx Power B.V. Within such analysis, it is shown that a non-optimized closed-loop flight control system can generate power to within 10% of the open-loop optimal flight trajectories. Additionally, results demonstrate that the system efficiency does not depend on the trajectory topology, though a significant change in terms of trajectory shape is observed for different wind speeds as a result of trajectory constraints.
•The average power output is not sensitive with respect to the trajectory shape.•The power curve can be obtained prior to real flight test experiments.•The proposed method is validated via real flight test experiments.•Circular trajectories are compared against lemniscate trajectories.•Optimized flight trajectories change significantly for different wind speeds.
Body condition score (BCS) is considered an important tool for management of dairy cattle. The feasibility of estimating the BCS from digital images has been demonstrated in recent work. Regression ...machines have been successfully employed for automatic BCS estimation, taking into account information of the overall shape or information extracted on anatomical points of the shape. Despite the progress in this research area, such studies have not addressed the problem of modeling the shape of cows to build a robust descriptor for automatic BCS estimation. Moreover, a benchmark data set of images meant as a point of reference for quantitative evaluation and comparison of different automatic estimation methods for BCS is lacking. The main objective of this study was to develop a technique that was able to describe the body shape of cows in a reconstructive way. Images, used to build a benchmark data set for developing an automatic system for BCS, were taken using a camera placed above an exit gate from the milking robot. The camera was positioned at 3m from the ground and in such a position to capture images of the rear, dorsal pelvic, and loin area of cows. The BCS of each cow was estimated on site by 2 technicians and associated to the cow images. The benchmark data set contained 286 images with associated BCS, anatomical points, and shapes. It was used for quantitative evaluation. A set of example cow body shapes was created. Linear and polynomial kernel principal component analysis was used to reconstruct shapes of cows using a linear combination of basic shapes constructed from the example database. In this manner, a cow's body shape was described by considering her variability from the average shape. The method produced a compact description of the shape to be used for automatic estimation of BCS. Model validation showed that the polynomial model proposed in this study performs better (error=0.31) than other state-of-the-art methods in estimating BCS even at the extreme values of BCS scale.
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•The homogenization method applied to collect ricotta cheese samples affected the TS contents of the products.•The repeatability and the standard deviation of repeatability are ...indicators of agreement between repeated measures for TS contents.•Ultra-Turrax homogenization provides repeatable measurements when compared with others.•The use of a better homogenization method results in a better estimate of the data, reducing sources of uncertainty.
Ricotta cheese is an Italian dairy product obtained by heat-coagulation of the proteins in whey, resulting from cheese production. The homogenization method applied to collect ricotta cheese samples could affect the total solids (TS) contents of the products. The aim of this study was to determine the effects of 5 different homogenization methods of the samples collection applied for the accuracy in TS determination in ricotta cheese, including un-homogenized method (UNH), un-homogenized combined with the Ultra-Turrax (IKA-Werke GmbH & Co. KG) method (UNH-UTX), spoon-homogenized method (SPN), spoon-homogenized combined with Ultra-Turrax method (SPN-UTX), and Ultra-Turrax homogenized method (UTX). The repeatability and the standard deviation of repeatability are indicators of agreement between repeated measures for TS contents. Results reported that UNH ricotta cheese samples showed large variation in TS content with values ranging from 18.31% to 25.85% and a standard deviation of repeatability higher than 1%; SPN samples showed repeatability values higher than 0.35% and standard deviation of repeatability ranged until 1.36%, suggesting large variability even in this case; the Ultra-Turrax homogenization reported repeatability values lower than 0.1% and standard deviation of repeatability lower than 0.05%, indicating that this method provides repeatable measurements that may reduce the sources of uncertainty in TS determination.
The noise assessment at the receivers due to wind turbines in operation is usually performed through outdoor measurements. Background noise and wind turbines noise (WTN) are related to wind speed and ...both contribute to the overall measured noise levels (environmental noise). Nevertheless, the relation between noise and wind speed is not easily predictable, especially when the wind farms are installed in hilly terrains, where the wind shear is truly remarkable. In Italy and in other countries, this kind of assessment is even more difficult to perform due to the national regulations that require to compute the difference between environmental and background noise levels with the same weather conditions. Thus, to get a reliable and approved measure of the residual noise it would be necessary to turn off the wind farm. This work suggests a technical procedure to simultaneously estimate the immission and the residual noise components measured nearby a wind farm when the residual noise is mainly generated by wind. This allows the evaluation of the noise impact produced by operational wind farms, without requiring the farm shut down. The method aims to be fairly straightforward, thus maintaining the required scientific basis to be used as an assessment procedure by consultants and public bodies.
The use of road surfaces with low noise emission characteristics is one of the actions mostly applied all over the world to decrease the number of road traffic noise annoyed people. Since many ...Italian roads are going to be paved with such surfaces, the LEOPOLDO project (funded by the Tuscany Region and the Italian Ministry of Transportation) was planned to check the efficacy in time of this action. Among all solutions, rubberized road surface is one of the most applied in USA, Canada, Europe and Asia. This paper describes results obtained by monitoring four rubberized surfaces one year after the laying and by evaluating the time stability of LEOPOLDO one by means of the Close Proximity method (CPX). All surfaces here analyzed are laid in real scenarios, so the actual efficacy of this action is evaluated. The results on the LEOPOLDO surface show spatial homogeneity, a good time stability and a significant noise emission reduction. Instead, analysis of the four rubberized surfaces shows variability in the results, probably due to the pavement installation quality, as supported by the data. Thus, the rubberized road surface looks to be a very efficient mitigation technology, providing the installation have been carried out with care and proficiency.
This paper proposes a tool to optimize the mix design of low-noise pavements. An experimental model was developed to predict the rolling noise of a reference car tire as a function of the composition ...and volumetric characteristics of mixes obtained from in-service pavements. The model enables an analyst to identify which composition parameters need to be altered to improve the acoustic performance of a low-noise pavement. To define the experimental model, several types of asphalt surface layers composed of hot-mix asphalt mixtures with different void contents, different aggregate grading, and different bitumen percentages were analyzed in situ and by laboratory tests. The acoustical properties of pavement surfaces were evaluated by the close-proximity method. The model was defined by using a multivariate nonlinear regression technique to relate composition and volumetric characteristics of asphalt mixtures with rolling noise levels recorded at different speeds. This model, which is a function of several significant parameters of asphalt mixture composition and tire speed, has proved to be highly reliable in predicting car tire rolling noise. Because the model enables the identification of mixture characteristics that require modification in relation to the specific value of the mean traffic speed, it is particularly useful for the optimization of low-noise pavement mix design.
Aircraft noise is a very important environmental problem that has been addressed in many ways over the years. Many strategies have been developed to mitigate aircraft noise exposure. To help identify ...the problem, computer simulations with mathematical models for aircraft noise have been developed. However, those models do not consider urban morphology effects on aircraft noise propagation. Urban morphology contains a set of features that modify noise, and it is necessary to be aware of its effects as it can be a factor that can potentially increase sound pressure levels to which the general population is exposed. This paper evaluates different aspects of urban morphology and determines the impact of street topologies, line of sight angles of buildings, façade positions, façade heights, and the combination of street topologies and LOS angles on aircraft noise. Measurements in front of the façade and in free field conditions were performed around buildings that make up educational facilities near Madrid Adolfo Suárez Barajas and Pisa Galileo Galilei airports. With the experimental work, it was demonstrated that front façades, U topologies, and greater LOS angles result in higher levels on façade as all these factors contribute to the transmission of noise in an urban environment. Correction factors for measurements made in façades with and without direct transmission with similar surroundings to the ones measured in this study and within a 95% confidence level were proposed for extrapolating the levels of aircraft noise events in free field conditions.
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