719 research outputs found
Quality characteristics of healthy dry fermented sausages formulated with a mixture of olive and chia oil structured in oleogel or emulsion gel as animal fat replacer
This article belongs to the Special Issue New Strategies for Innovative and Enhanced Meat and Meat Product.The present work evaluates the suitability of beeswax oleogels and emulsion gel prepared with a healthy lipid mixture (olive and chia oils) as pork fat replacers for the development of a dry fermented meat product (fuet). Because these systems offer various possibilities, this study has compared their effect on the nutritional quality and sensory acceptability of fuets and their behaviour with regard to technological properties and microbiological and oxidative stability during 30 days of chilled storage. This strategy allowed products with an improved fatty acid profile and a 12-fold decrease of the polyunsaturated fatty acids (PUFA) n-6/n-3 ratio, as compared to the control samples. Irrespective of the structuring method used as animal fat replacer, reformulated samples showed a good oxidative status during chilled storage. In general, no differences that depended on the use of oleogel or emulsion gel were observed in the technological properties and microbiological status, so the choice of one or the other would be conditioned by other factors than the characteristics that the product develops. However, further studies are needed to improve the sensory attributes of the reformulated samples.This research was funded by the Spanish Ministry of Economy and Competitiveness, AGL2014-53207-C2-1-R and PID2019-103872RB-I00, and the Intramural 202070E177 was funded by The Spanish National Research Council (CSIC)Peer reviewe
Coupling the dynamics and the molecular chemistry in the Galactic center
The physical conditions of the Galactic center (GC) clouds moving with
non-circular velocities are not well-known. We have studied the physical
conditions of these clouds with the aim of better understanding the origin of
the outstanding physical conditions of the GC molecular gas and the possible
effect of the large scale dynamics on these physical conditions.Using published
CO(1-0) data, we have selected a set of clouds belonging to all the kinematical
components seen in the longitude-velocity diagram of the GC. We have done a
survey of dense gas in all the components using the J=2-1 lines of CS and SiO
as tracers of high density gas and shock chemistry. We have detected CS and SiO
emission in all the kinematical components. The gas density and the SiO
abundance of the clouds in non-circular orbits are similar those in the nuclear
ring (GCR). Therefore, in all the kinematical components there are dense clouds
that can withstand the tidal shear. However, there is no evidence of star
formation outside the GCR. The high relative velocity and shear expected in the
dust-lanes along the bar major axis could inhibit the star formation process,
as observed in other galaxies. The high SiO abundances derived in the
non-circular velocity clouds are likely due to the large-scale shocks that
created the dust lanesComment: One figure as an independent PDF file. Accepted by A&
On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core
The detection of organic molecules with increasing complexity and potential
biological relevance is opening the possibility to understand the formation of
the building blocks of life in the interstellar medium. One of the families of
molecules with astrobiological interest are the esters, whose simplest member,
methyl formate, is rather abundant in star-forming regions. The next step in
the chemical complexity of esters is ethyl formate, CHOCHO. Only two
detections of this species have been reported so far, which strongly limits our
understanding of how complex molecules are formed in the interstellar medium.
We have searched for ethyl formate towards the W51 e2 hot molecular core, one
of the most chemically rich sources in the Galaxy and one of the most promising
regions to study prebiotic chemistry, especially after the recent discovery of
the PO bond, key in the formation of DNA. We have analyzed a spectral line
survey towards the W51 e2 hot molecular core, which covers 44 GHz in the 1, 2
and 3 mm bands, carried out with the IRAM 30m telescope. We report the
detection of the trans and gauche conformers of ethyl formate. A Local
Thermodynamic Equilibrium analysis indicates that the excitation temperature is
7810 K and that the two conformers have similar source-averaged column
densities of (2.00.3)10 cm and an abundance of
10. We compare the observed molecular abundances of ethyl formate
with different competing chemical models based on grain surface and gas-phase
chemistry. We propose that grain-surface chemistry may have a dominant role in
the formation of ethyl formate (and other complex organic molecules) in hot
molecular cores, rather than reactions in the gas phase.Comment: Accepted in A&A; 11 pages, 6 figures, 7 Table
Warm H2 in the Galactic center region
We present ISO observations of several H2 pure-rotational lines (from S(0) to
S(5)) towards a sample of 16 molecular clouds distributed along the central ~
500 pc of the Galaxy. We also present C18O and 13CO J=1->0 and J=2->1
observations of these sources made with the IRAM-30m telescope. With the CO
data we derive H2 densities of 10e(3.5-4.0) cm-3 and H2 column densities of a
few 10e22 cm-2. We have corrected the H2 data for ~ 30 magnitudes of visual
extinction using a self-consistent method. In every source, we find that the H2
emission exhibits a large temperature gradient. The S(0) and S(1) lines trace
temperatures (T) of ~150 K while the S(4) and S(5) lines indicate temperatures
of ~ 600K. The warm H2 column density is typically ~1-2 x 10e22 cm-2, and is
predominantly gas with T=150 K. This is the first direct estimate of the total
column density of the warm molecular gas in the Galactic center region. These
warm H2 column densities represent a fraction of ~ 30 % of the gas traced by
the CO isotopes emission. The cooling by H2 in the warm component is comparable
to that by CO. Comparing our H2 and CO data with available ammonia NH3
observations from literature one obtains relatively high NH3 abundances of a
few 10e(-7) in both the warm and the cold gas. A single shock or
Photo-Dissociation Region (PDR) cannot explain all the observed H2 lines.
Alternatives for the heating mechanisms are discussed.Comment: 14 pages including figures, to be published in A&
Large scale grain mantle disruption in the Galactic Center
We present observations of C2H5OH toward molecular clouds in Sgr A, Sgr B2
and associated with thermal and non-thermal features in the Galactic center.
C2H5OH emission in Sgr A and Sgr B2 is widespread, but not uniform. C2H5OH
emission is much weaker or it is not detected in some molecular clouds in both
complexes, in particular those with radial velocities between 70 and 120 km/s.
While most of the clouds associated with the thermal features do not show
C2H5OH emission, that associated with the Non-Thermal Radio Arc shows emission.
The fractional abundance of C2H5OH in most of the clouds with radial velocities
between 0 and 70 km/s in Sgr A and Sgr B2 is relatively high, of few 1e-8. The
C2H5OH abundance decreases by more than one order of magnitude (aprox. 1e-9) in
the clouds associated with the thermal features. The large abundance of C2H5OH
in the gas-phase indicates that C2H5OH has formed in grains and released to
gas-phase by shocks in the last aprox. 1e5 years.Comment: In press in Astrophysical Journal Letters 7 pages, 1 table, 1 figur
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