1,721,410 research outputs found
Hammer crusher vs. disk crusher: influence of working temperature on the quality and preservation of virgin olive oil
No full textAn investigation was carried out using a hammer-
crusher and a disk-crusher for olive paste preparation
to evaluate the effects of different processing temperatures
on the quality of the virgin olive oils obtained.
The tests performed showed that hammer-crushing produces
a more intense fragmentation of the olive pits than
the disk-crusher, thus resulting in a more substantial increase
in output temperature. Higher temperatures in the
crusher during olive processing lead to a shorter preservation
of the oils. All the analytical determinations performed
also showed that the oils obtained from hammercrushed
pastes presented a greater degradation than those
from disk-crushed pastes. These findings were further
confirmed by the oven test results
Indagine sensoriale su salsicce stagionate per la definizione delle caratteristiche organolettiche
No full textAn experimental investigation was carried out
with the aim to characterise the quality of
industrial ripened sausages by sensory analysis.
The organoleptic assessment of sausages was
performed by a trained sensory panel of 10
members. The obtained results showed a general
positive assessment of tasters towards the
products under analysis. In fact a high score was
attributed to the descriptors “global flavour” and
“ripened flavour” while very low score was given
to the descriptors bitter, acid, sour-pungent,
rancid smell/taste, mouldy smell/taste. Finally,
a significant correlation (p<0.01) was found
between global flavour and ripened flavour
Influenza delle tecniche di preparazione della pasta di olive sulla qualità dell’olio. Nota II. Evoluzione delle sostanze fenoliche e di alcuni parametri di qualità in funzione della maturazione delle drupe in olio di oliva vergine della cv Coratina
No full textLa qualità di salsicce stagionate: composizione in acidi grassi della frazione lipidica
No full textAn investigation was carried out to evaluate the
quality of ripened sausages in relation to the
fatty acid composition of their lipid fraction. In
particular, PUFA/SFA and n-6/n-3 PUFA ratios
as well as the amounts of trans isomers of
unsaturated fatty acids were considered, due to
their importance from the nutritional point of
view. On the whole, SFA (mean value 42.79%)
and MUFA (mean value 47.80%) contents were
higher than PUFA content (mean value 9.41%).
As a consequence the PUFA/SFA ratio (mean value
0.22) was lower than that recommended for
human diet. On the contrary, the n-6/n-3 PUFA
ratio (mean value 12.65) was higher than the
recommended value. The mean content of trans
isomers was 0.92%
Marcatori molecolari in olivo: situazione attuale e potenziali applicazioni agli oli vergini
No full textDNA analysis by means of molecular markers enables, among its possible applications, genome fingerprinting with consequent identification of different individuals. In the matter of agro-food this can have interesting applications enabling identification of both monovarietal row material and processed products. The various categories of molecular markers employed in Olea europaea L. with cultivar identification purposes are described and their potential application to virgin oils is evaluated. This, with the aim of detecting the presence of not declared cultivars in recognised preserved origin (DOP) oils
Posibility to improve the quality characteristics of olive-pomace oils and to enhance differentiation with refined olive-pomace oil
No full textAn investigation was carried out to evaluate the oxidative and hydrolytic degradation of 37
olive-pomace oils marketed in southern Italy and to compare the results with those obtained from 10
deodorised olive-pomace oils representative of large stocks of oil obtained after the ®nal step of
re®ning. One aim of the research was to ascertain the quality characteristics of commercial olivepomace
oils; another was to verify whether the legally prescribed addition of virgin olive oil to re®ned
pomace oil, so that the ®nal product may be classi®ed commercially as olive-pomace oil, was actually
suf®cient to justify upgrading. The analytical methods used were silica gel column chromatography
and high-performance size exclusion chromatography. The data obtained showed that the ®nal retail
olive-pomace oils had a lower degree of oxidative degradation than the re®ned oils, as indicated by the
lower values obtained when summing the proportions of triglyceride oligopolymers and oxidised
triglycerides. Conversely, hydrolytic degradation, which was evaluated by determining diglycerides,
proved to be the same in the two categories of oil. The proportions of virgin olive oil added are small, as
indicated by the statistically indistinguishable values of triglyceride oligopolymers and free fatty acids
obtained. The possibility of setting a limit to the amount of triglyceride oligopolymers present in the
commercial category of olive-pomace oil has been considered. This limit would ensure standardisation
of the level of oxidation and, consequently, of the quality of marketed oils and would enhance differentiation between olive-pomace oil and re®ned olive-pomace oil
Method for picosecond time interval measurements based on frequency-switching sinusoidal shape
No full textIf the wave output by a voltage controlled oscillator (VCO) has the property of having no phase jump also when its frequency is swiftly changed, the measures of the phase before and after a fast frequency change can be used for calculating the time at which such event has occurred. Based on this property, a precise time measurement instrument has been designed and built. A non-optimised version has better than 100ps resolution full width at half maximum, is VCO drift compensated and is able to time events against a stable clock running at 312.5MHz. The VCO frequency of the prototype jumps from 47 to 59MHz. The analogue hardware is fairly limited. Applications may range from particle timing to time resolved fluorescence spectroscopy to range finding through time-of-flight method
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