1,721,111 research outputs found
Mathematical Modelling of Heat Transfer in Mortadella Bologna PGI during Evaporative Pre-Cooling
No full textMortadella evaporative pre-cooling process from 70 to 50°C at core was investigated: the thermal diffusivity and the apparent heat transfer coefficient were experimentally estimated. The effects of ventilation and water spraying with different intervals (0, 5, 10 and 15 min) were tested and core and surface temperatures, cooling times and cook values were compared. Water spraying every 5 min combined with ventilation allowed obtaining both lowest cooling time and cook values in the product. On the contrary, continuous spraying (no interval) presented higher cooling times since probably, after a certain time, water formed a continuous film on product surface, which prevented evaporation. Based on the experimental data, a finite differences mathematical model, previously applied to Mortadella cooking process, was developed and validated by means of two cooling procedures. Acceptable approximation and low percentage errors on final core temperature were obtained, confirming the usefulness and reliability of the proposed model
Indagine storico – statistica sulle cause di non conformità delle cosce fresche e dei prosciutti stagionati per la DOP “Prosciutto di Parma”
No full textElectronic nose evaluation of volatile emission of Chinese teas: from leaves to infusions
No full textAn electronic nose can be used to discriminate tea leaf quality, but to the best of the author's knowledge, studies that address the changes in electronic sensor signals between tea leaves and infusions are not available. In this framework, this preliminary work compared the volatile emissions of leaf samples belonging to the basic Chinese teas (white, yellow, green, oolong, black and pu erh) with those of their respective infusions using an electronic nose. Different signal responses were qualitatively and quantitatively obtained from the sensors both for the tea leaves and their respective infusions, showing that the leaf aroma is not transferred as it is into the beverage. The teas were grouped according to the different fermentation techniques based on the percentage variations in the sensor contributions to the complete description of the volatile profiles. The results indicated that the electronic nose is a suitable tool to monitor the volatile emission differences that occur between leaves and infusions in different tea types
Pomegranate: Production, Products and Processing
No full textPomegranate fruit and pomegranate products have recently received great attention for their health benefits, mainly due to their high polyphenols content and the related antioxidant capacity. Nevertheless, the pomegranate processing and its effects on health value of pomegranate juice deserve more attention. In this chapter, an overview on all the products obtained from pomegranate is available with particular reference to the different plant solutions and technologies for producing these products. Moreover, the effects of processing on quality attributes of pomegranate are also reporte
Pecorino of Appenino Reggiano cheese: evaluation of ripening time using selected physical properties
No full textPhysico-chemical properties (texture, colour and image analysis) of Pecorino of Appennino Reggiano cheese were evaluated on six cheese samples at different ripening times (0, 80, 90, 150, 180 and 240 days). Hardness values, obtained by means of texture profile analysis and fracture test, as well as Young's modulus values, significantly increased during ripening. Among other textural parameters, cohesiveness decreased significantly from 0 to 80 days and then remained unchanged for the rest of the ripening time, whereas adhesiveness and springiness did not exhibit a linear trend. L*, b* and C* values decreased significantly with ripening, whereas the percentage area occupied by holes remained unaltered. A statistical model was developed to predict ripening time by means of a step-wise multiple linear regression analysis based on five textural properties (hardness, cohesiveness, chewiness, hardness at fracture and Young' modulus) and three colour parameters (L*, b* and C) (R(2) = 0.984). The model was applied to a validation set of six samples from different milk lots and successfully predicted ripening time with good reproducibility and accuracy (R(2) = 0.971)
An innovative mathematical method for the thermal diffusivity estimation and thermal process modelling.
No full textSelf-T-dual brane cosmology and the cosmological constant problem
Full text linkWe consider a codimension-one brane embedded in a gravity-dilaton bulk
action, whose symmetries are compatible with T-duality along the space-like
directions parallel to the brane, and the bulk time-like direction. The
equations of motions in the string frame allow for a smooth background obtained
by the union of two symmetric patches of AdS space. The Poincar\'e invariance
of the solution appears to hold independently of the value of the brane vacuum
energy, through a self-tuning property of the dilaton ground state. Moreover,
the effective cosmology displays a bounce, at which the scale factor does not
shrink to zero. Finally, by exploiting the T-duality symmetry, we show how to
construct an ever-expanding Universe, along the lines of the Pre-Big Bang
scenario
Experimental determination of thermal diffusivity using a numerical technique to solve heat transfer equation in conductive foods
No full textTrattamenti termici di pasta e prodotti da forno: valutazione di indici chimici e colorimetrici
No full textCorrelation between different markers for the assessment of red chilli pepper powders stability during shelf-life
No full textPungency and red colour of Capsicum powders deteriorate during processing and storage, resulting
in a decrease in market value. Two varieties of pepper with different pungencies were monitored
for capsaicinoids, colour and furosine. Aliquots were stored at room and at low temperature
during one year. At low temperature all indicators were stable in both varieties, while at room
temperature, redness and capsacinoids decreased significantly, while furosine increased. High correlation
was found between those markers. The more pungent variety exhibited higher stability in
terms of all parameters. Differences observed suggest a potential protective effect exerted by capsaicinoids
on powder stability. The decrease in capsaicinoids and redness accompanied by furosine
increase showed a linkage between those markers never reported before. Considering that
capsaicinoids and furosine occurrence have strong impact on the nutritional profile, the findings
of this work show relevant changes in the nutritional value of chilli pepper powder after storage
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