Partial dealcoholisation of red wines by membrane contactor technique: influence on colour, phenolic compounds and saliva precipitation index

In this study, red wines from different grape varieties (Merlot, Aglianico and Piedirosso) and containing different alcoholic level (from 13.67 to 15.46% v/v) were treated to diminish the alcoholic percentage of 2, 3 and 5% v/v by a polypropylene hollow fibre membrane contactor apparatus. The wines were analysed before and after partial dealcoholisation. Colour indexes and phenolics were analysed by spectrophotometric methods and HPLC. Wine astringency was evaluated by an astringency index based on the ability of treated wines to precipitate salivary proteins (SPI, Saliva Precipitation Index). For all the levels of dealcoholisation studied, changes in chromatic characteristics, Folin–Ciocalteu index and vanillin reactive flavans were below the methodological errors of the analyses. A loss of malvidin 3-monoglucoside was detected after the dealcoholisation process. Decreasing the ethanol content of wines caused an increase in SPI values.     

Effect of Surface Density on the Engineering Properties of High Methoxyl Pectin-Based Edible Films

The effect of pectin surface density (ρ _s) on the engineering properties of high methoxyl (HM) pectin-based edible films was determined in order to explore the role of ρ _s on structure and functional properties. Films at different ρ _s values (2.5, 3.2, 3.8, 4.5, 5.1, 5.8 mg cm⁻²) were analyzed by means of microscopy, thermal, mechanical, and barrier (water vapor permeability WVP, oxygen permeability \textkP_\textO2 {\text{kP}}_{{{\text{O}}_2 }} , carbon dioxide permeability \textkP_\textCO2 {\text{kP}}_{{{\text{CO}}_2 }} ) properties. Microscopy, thermal, and mechanical results showed that by increasing ρ _s from 2.5 to 5.8 mg cm⁻², the film structure does not change. HM pectin-based film has a tensile strength of 20 ± 7 MPa and an elastic modulus (E) equal to 2,400 ± 200 MPa. However, it is quite brittle as the elongation to break (e) is close to 1%. Although the film structure was unaffected by ρ _s, WVP increased with the rise in ρ _s while \textkP_\textO2 {\text{kP}}_{{{\text{O}}_2 }} and \textkP_\textCO2 {\text{kP}}_{{{\text{CO}}_2 }} decreased. On the whole, HM pectin-based film showed barrier properties comparable to biodegradable commercial film and low selectivity.     

HPLC-ESI-MS/MS assessment of the tetrahydro-metabolites of cortisol and cortisone in bovine urine: promising markers of dexamethasone and prednisolone treatment

The effects of long-term administration of low doses of dexamethasone (DX) and prednisolone (PL) on the metabolism of endogenous corticosteroids were investigated in veal calves. In addition to cortisol (F) and cortisone (E), whose interconversion is regulated by 11β-hydroxysteroid dehydrogenases (11βHSDs), special attention was paid to tetrahydrocortisol (THF), allo-tetrahydrocortisol (aTHF), tetrahydrocortisone (THE) and allo-tetrahydrocortisone (aTHE), which are produced from F and E by catalytic activity of 5α and 5β-reductases. A specifically developed HPLC-ESI-MS/MS method achieved the complete chromatographic separation of two pairs of diastereoisomers (THF/aTHF and THE/aTHE), which, with appropriate mass fragmentation patterns, provided an unambiguous conformation. The method was linear (r² > 0.9905; 0.5–25 ng ml^?1), with LOQQ of 0.5 ng ml^?1. Recoveries were in range 75–114%, while matrix effects were minimal. The experimental study was carried out on three groups of male Friesian veal calves: group PL (n = 6, PL acetate 15 mg day^–1 p.o. for 31 days); group DX (n = 5, 5 mg of estradiol (E2) i.m., weekly, and 0.4 mg day^–1 of DX p.o. for 31 days) and a control group (n = 8). Urine was collected before, during (twice) and at the end of treatment. During PL administration, the tetrahydro-metabolite levels decreased gradually and remained low after the suspension of treatment. DX reduced urinary THF that persisted after the treatment, while THE levels decreased during the experiment, but rebounded substantially after the DX was withdrawn. Both DX and PL significantly interfered with the production of F and E, leading to their complete depletion. Taken together, the results demonstrate the influence of DX and PL administration on 11βHSD activity and their impact on dysfunction of the 5-reductase pathway. In conclusion, profiling tetrahydro-metabolites of F and E might serve as an alternative, indirect but reliable, non-invasive procedure for assessing the impact of synthetic glucocorticosteroids administration.     

Anti‐inflammatory activity of rosemary extracts obtained by supercritical carbon dioxide enriched in carnosic acid and carnosol

The in vitro anti‐inflammatory activity of supercritical rosemary (Rosmarinus officinalis L.) extracts (rosemary A and B) is been reported in this study. To achieve that, THP‐1 macrophages were activated using lipopolysaccharide or human ox‐LDL and secretion and gene expression of TNF‐α, IL‐1β, IL‐6 and IL‐10 were evaluated, as well as COX‐2 gene expression. Results indicated that both rosemary extracts (A & B) exhibit high anti‐inflammatory activity although at a higher extent in case of rosemary B extract (5 μg mL^?1), representing a higher quantity of carnosic acid and carnosol than rosemary A. When comparing the activity of the extract to the standard itself, the anti‐inflammatory activity of standards of carnosic acid and carnosol was not as intense as that obtained with rosemary B. These data indicated that although carnosic acid content in the extracts is considered as the main anti‐inflammatory compound, a synergistic interaction with other compounds may play a significant role in enhancing its activity. Results provided the grounds for possible increase in the application of supercritical rosemary extracts in food formulations for mitigation or prevention of inflammatory diseases.     

Nanoscale characterization of the biomechanical hardening of bovine zona pellucida

The zona pellucida (ZP) is an extracellular membrane surrounding mammalian oocytes. The so-called zona hardening plays a key role in fertilization process, as it blocks polyspermy, which may also be caused by an increase in the mechanical stiffness of the ZP membrane. However, structural reorganization mechanisms leading to ZP''s biomechanical hardening are not fully understood yet. Furthermore, a correct estimate of the elastic properties of the ZP is still lacking. Therefore, the aim of the present study was to investigate the biomechanical behaviour of ZP membranes extracted from mature and fertilized bovine oocytes to better understand the mechanisms involved in the structural reorganization of the ZP that may lead to the biomechanical hardening of the ZP. For that purpose, a hybrid procedure is developed by combining atomic force microscopy nanoindentation measurements, nonlinear finite element analysis and nonlinear optimization. The proposed approach allows us to determine the biomechanical properties of the ZP more realistically than the classical analysis based on Hertz''s contact theory, as it accounts for the nonlinearity of finite indentation process, hyperelastic behaviour and material heterogeneity. Experimental results show the presence of significant biomechanical hardening induced by the fertilization process. By comparing various hyperelastic constitutive models, it is found that the Arruda–Boyce eight-chain model best describes the biomechanical response of the ZP. Fertilization leads to an increase in the degree of heterogeneity of membrane elastic properties. The Young modulus changes sharply within a superficial layer whose thickness is related to the characteristic distance between cross-links in the ZP filamentous network. These findings support the hypothesis that biomechanical hardening of bovine ZP is caused by an increase in the number of inter-filaments cross-links whose density should be higher in the ZP inner side.     

Optimal temperature for the control of the product quality in batch polymerization: Simulation and experimental results

A method to determine an optimal temperature profile that guarantees products having controlled molecular weight distribution (MWD) and desired values of molecular weight (M_w) is presented. The base case is the batch polymerization of MethylMethAcrylate, initiated by AIBN. On the basis of the kinetic model, the optimal temperature profile is determined by imposing that the value of the instantaneous chain length is maintained constant, thus counteracting the effects of the increase of viscosity, which leads to broad MWD. Some approximations permit to express, in a straightforward way, the relationship between the optimal temperature and the conversion as a function of the initial conditions. The validity of the simplifying hypotheses that have been assumed is confirmed first by simulation results and then by a comparison with experimental runs conducted in a labscale unit, with determination of MWD made by means of GPC. The obtained results suggest that it is possible to decouple the problem: acting on the operating temperature to control the MWD, acting on initial temperature and initiator concentration to influence the M_w. The possibility of application to industrial reactors has also been investigated, taking into account their peculiarities and constraints. © 1995 John Wiley & Sons, Inc.     

Temporal Variations in Water Chemistry at Abandoned Underground Mines Hosted in a Carbonate Environment

Abstract  Closure of Pb-Zn mines in the Iglesias district (SW Sardinia, Italy) caused the cessation of pumping in 1997, and the consequent flooding of underground workings. Deep saline water mixed with the shallow groundwater as the water table rose, increasing salinity. Stratification caused the saline water at depth to settle over a period of three years. At the beginning of rebound, an increase in dissolved Zn, Cd, Pb, and Hg was observed under near-neutral pH conditions. Following peak concentrations, a marked decrease of Zn, Cd, and Hg, and to a lesser extend Pb, occurred. After 7 years of rebound, the concentrations of these metals are relatively low at most mine sites, although the levels are generally still higher than in unmined areas. Nowadays, the highest release of metals to the aquatic system occurs from the weathering of tailings and mine wastes.     

Disentangling time in a near-field approach to scanning probe microscopy

Microwave microscopy has recently attracted intensive effort, owing to its capability to provide quantitative information about the local composition and the electromagnetic response of a sample. Nonetheless, the interpretation of microwave images remains a challenge as the electromagnetic waves interact with the sample and the surrounding in a multitude of ways following different paths: microwave images are a convolution of all contributions. In this work we show that examining the time evolution of the electromagnetic waves allows us to disentangle each contribution, providing images with striking quality and unexplored scenarios for near-field microscopy.     

Characterisation of a lard cured with spices and aromatic herbs

The study considered the proximate composition, pH, free acidity, MDA and peroxide values of a cured and ripened lard covered with spices and aromatic herbs, these latter parameters, due to lipolytic endoenzymatic phenomena, tended to increase until the end of the salting period. Throughout the production phases the bacterial load was very low. The final vacuum-packed product had a shelf-life of about 90 days and its fatty acid and cholesterol composition was typical of lard. A GC/MS study of the spices/herbs in the lard highlighted which components came from the spices/aromatic herbs and which came from phenomena due to lipolytic endoenzymatic processes.