The role of fat in flavor perception: effect of partition and viscosity in model emulsions

Decreasing the fat content of a food, while maintaining the same aroma content, changes both aroma release (due to partition effects) and the viscosity of the food. To understand the relative contribution of these two factors on flavor perception, a series of flavored emulsions were prepared to control aroma release and viscosity using different aroma, oil, and hydroxypropyl methyl cellulose (HPMC) contents. Samples were formulated to deliver the same aroma-release in vitro and in vivo, and their viscosity was measured using the Kokini oral shear stress parameter. Despite the in vivo aroma release being constant, there were perceptual differences between the samples, and the flavor intensity decreased as in-mouth viscosity increased. For these iso release samples, the Kokini oral shear stress parameter correlated well with the decrease in perception, suggesting that there may be a viscosity stimulus or that the viscosity affects release of tastant and hinders aroma-taste interactions.     

Potential of Tamarix africana and other halophyte species for phytostabilisation of contaminated salt marsh soils

Purpose

Salt marsh plants are colonising wastes from a steel plant deposited on the Coina River Banks posing a potential contamination risk to the Tagus estuary ecosystem. The objectives of this study were to assess the uptake, accumulation and translocation of hazardous elements/nutrients in three spontaneous halophytic species, to evaluate the capacity of Tamarix africana to stabilise a contaminated salt marsh soil, and to evaluate the ecotoxicity of the pore water and elutriates from phytostabilised soils.

Materials and methods

The work comprises the following: fieldwork collection of soil samples from Coina River (an affluent of Tagus River) bank landfill, estuarine water and spontaneous plants (Aster tripolium, Halimione portulacoides and Sarcocornia sp.), and greenhouse studies (microcosm assay) with T. africana growing in one landfill salt marsh soil, for 97 days, and watered with estuarine water. Soils were analysed for pH, EC, C_organic, NPK, iron and manganese oxides. Soils total (acid digestion) elemental concentrations were determined by ICP/INAA. Estuarine waters, plants roots and shoots (acid digestion), soils available fraction (diluted organic acids extraction-RHIZO or pore water), and salts collected from the T. africana leaves surface were analysed for metals/metalloids (ICP-MS). Ecotoxicity assays were performed in T. africana soil elutriates and pore waters using Artemia franciscana and Brachionus plicatillis.

Results and discussion

Soils were contaminated, containing high total concentrations of arsenic, cadmium, chromium, copper, lead and zinc. However, their concentrations in the available fraction were <4 % of the total. The estuarine waters were contaminated with cadmium, but negligible ecotoxicological effect was observed. The spontaneous plants had significant uptake of the above elements, being mostly stored in the roots. Elemental concentrations in the shoots were within the normal range for plants. These species are not hazardous elements accumulators. Tamarix africana was well adapted to the contaminated saline soils, stored the contaminants in the roots, and had small concentrations of hazardous elements in the shoots. Excretion of hazardous elements by the salt glands was also observed. Elutriates from soils with and without plant did not show ecotoxicity.

Conclusions

The salt marsh species play an important role in the stabilisation of the soils in natural conditions. Tamarix africana showed potential for phytostabilisation of saline-contaminated soils. The low translocation of the elements from roots to shoots and/or active excretion of the elements by the salt glands was a tolerance mechanism in T. africana.

     

Pheochromocytomas and paragangliomas in humans and dogs

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are described in several species. In humans and dogs they have many similarities: the excessive catecholamine release in hormonally active PCC causes similar clinical signs, the frequency of metastasis is similar, and they are histopathologically almost identical. Surgery is curative when PCC and PGL have not metastasized, while only palliative treatment is possible for patients with metastatic disease. Mutations in succinate dehydrogenase subunit B (SDHB) are associated with metastatic behaviour in human PCC/PGL and the same mutation has been described in dogs. The dog might therefore be a suitable model for study of the pathogenesis of metastatic PCC and PGL in humans. Further molecular studies of common tumourigenic pathways and comparative studies of histopathology of human and canine PCC and PGL are warranted.     

Identification of candidate genes for paratuberculosis resistance in the native Italian Garfagnina goat breed

Paratuberculosis disease is a chronic bacterial disease infection of ruminants of global relevance, caused by MAP (Mycobacterium avium subsp. paratuberculosis). The present study was conducted on the Garfagnina goat breed that is an Italian native goat population registered on the Tuscan regional repertory of genetic resources at risk of extinction. Forty-eight adult goats (27 serologically positive to MAP-positive and 21 serologically negative to MAP-negative) belonging to a single flock that had experienced annual mortalities due to MAP infection were identified and genotyped with the Illumina GoatSNP60 BeadChip. Diagnosis was achieved by serological tests, as well as post-mortem examination of affected animals. A genome-wide scan was then performed on the individual marker genotypes, in an attempt to identify genomic regions associated with MAP infection disease. Nine significant markers were highlighted and they were located within, or nearby, annotated genes. Two genes found in this study encode are linked to protein kinases that are among the most important enzymes involved in the immune response to Johne’s disease, and four genes are involved in the functions of the Golgi complex.     

Can the extract of Aristolochia argentina Griseb affect the foraging decisions of the leaf cutting ant Acromyrmex lundi (Guérin)? Preliminary assays

ABSTRACT

The aim of this study was to evaluate whether foraging decisions of Acromyrmex lundi in the field are affected by the extract of Aristolochia argentina. A free choice test was performed using Rosa x hybrida leaves treated with the extract and control with acetone. Two leaves (treated and control) were presented on either side of a foraging trail. The percentage of removed material was recorded for 90 minutes of observation on two consecutive days. Dry weight and repellency index were calculated. Ant activity, the percentage of carried leaves and weight data were analyzed using a “t”-test for paired data, and a General Linear Mixed Model test was used to evaluate the different variables and their interactions. A. argentina extract (1%) did not affect the foraging activity of A. lundi, whereas the 5% dose caused significant differences in foraging activity as well as between the factors and the interactions. A repellency index of above 95% was obtained at the 5% dose. The extract of A. argentina could be considered for future management of this insect.     

Plastic response of four maritime pine (<Emphasis Type="Italic">Pinus pinaster</Emphasis> Aiton) families to controlled soil water deficit

Key message

Separating the internal (ontogenetic) and external (environmental) components of maritime pine development during controlled soil water deficit helps to highlight the plastic response. The adjusted measurements reveal significant differences between families for their plastic response for several physiology and growth traits.

Context

Soil water deficit is and will be a growing problem in some regions. Pinus pinaster Ait. is a species of commercial interest and is recognized as a drought-avoiding species. It is thus of interest to evaluate the adaptation potential of P. pinaster to soil water deficit.

Aims

This paper aims to estimate the plastic response to the variation of water availability at the family level (half-sibs).

Methods

Two-year-old P. pinaster cuttings from four families were submitted during 6 weeks to two contrasting watering regimes. The experiment started in April 2011 shortly after sprouting. The photosynthesis and stomatal conductance to water vapor were measured on 1-year-old needles. Intrinsic water-use efficiency was calculated as the ratio of photosynthesis to stomatal conductance. Radial growth, length of terminal shoot, and total height were also measured. The ontogenetic component of tree development was estimated on the well-watered trees for all the traits. Then, this development effect was eliminated from the data collected on the trees submitted to the soil water deficit in order to keep only the effect of this soil water deficit.

Results

After 6 weeks of reduced watering, the value of all adjusted traits decreased. An average plastic response to the variation of water availability was found to be significant and variable at the family level for the six adjusted variables.

Conclusion

These results suggest that there is genetic variation of phenotypic plasticity to drought in P. pinaster for several traits, including stomatal conductance, which appears to be a promising variable for future selection for resistance to drought.

     

Moisture Content and Oil Uptake in Potatoes (Cultivar Satina) During Deep-Fat Frying

In this study, the effect of ultrasonic sound (at 20- and 40-kHz frequency for 15 min) and drying (at 60 °C for 15 min) pretreatments on the moisture content and oil uptake of potato slices (cultivar Satina) during deep frying were studied. The potato slices were fried at temperatures of 170 and 190 °C for 5, 7 and 10 min. Samples pretreated with ultrasound at 20 kHz had higher moisture contents than those receiving the 40-kHz pretreatment. The highest moisture content was obtained at 20 kHz and frying at 170 °C for 5 min. On the other hand, samples pretreated with ultrasound at 40 kHz had higher effective water diffusivity coefficient and activation energy than those pretreated at 20 kHz. The highest effective water diffusivity coefficient was obtained at 40 kHz and frying at 190 °C for 5 min, whereas the highest activation energy belonged to pretreatment with 40 kHz and frying at 170 °C for 10 min. The range for effective water diffusivity coefficient was 6.95?×?10^?8 to 8.80?×?10^?8 m² s^?1 and that for activation energy was 13.161 to 16.307 kJ mol^?1. In addition, samples pretreated at 40 kHz had a lower oil uptake than those pretreated at 20 kHz. The highest oil uptake took place at 20 kHz, with frying at 170 °C for 10 min. Regression analysis revealed that an exponential model was best for predicting variations in moisture content and oil uptake of potato slices.     

Acute and Chronic Effects of Three Pharmaceutical Drugs on the Tropical Freshwater Cladoceran Ceriodaphnia silvestrii

Water, Air, & Soil Pollution - Phosphorus (P) is an essential element for all living organisms, and plays a major role in many physiological processes. However, in recent years, excessive...