1,985 research outputs found

    Drying kinetics and physico-chemical quality of mango slices

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    Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumer’s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model

    An integrated technological approach to the selection of lactic acid bacteria of flour origin for sourdough production

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    Several lactic acid bacteria (LAB) were evaluated in situ for their potential in sourdough fermentation. The strains belonged to Lactobacillus plantarum, Lactobacillus sakei, Lactobacillus sanfranciscensis, Leuconostoc citreum, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides and Weissella cibaria. LAB were used, in individual inocula, to carry out the fermentation of \u3b3-ray treated (sterile) flour and untreated commercial flour, in order to evaluate their performances both in the absence and presence of the native microbiota of flour. The pH and total titratable acidity (TTA) showed a strong and fast acidification of the experimental sourdough determined by W. cibaria and Ln. citreum strains. All strains were followed during fermentation by plate count. Randomly amplified polymorphic DNA (RAPD)-PCR analysis applied on the colonies isolated from the highest dilution of samples confirmed the dominance of the added strains in all sourdoughs prepared with sterile and non-sterile flour. The analysis of organic acids, performed by high-performance liquid chromatography (HPLC), confirmed that some W. cibaria and Ln. citreum strains showed an optimal fermentation quotient. The volatile organic compound (VOC) composition resulting from the gas chromatography coupled with mass spectrometry (GC/MS) analysis of sourdough headspace recognised 51 chemical compounds including acids, alcohols, aldehydes, esters, ketones, lactones, acetate, alkane, and phenol, most of which are of LAB origin and are relevant for the final bread. After baking, the breads were evaluated for the height of the central slices, colour of crust and crumb, hardness and number and distribution of alveolus. The combination of these results indicated that strains Ln. citreum PON10079 and PON10080 and W. cibaria PON10030 and PON10032 are suitable cultures to use in industrial production

    Testosterone Replacement Therapy

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    Male hypogonadism (HG) can be defined according to its etiology as primary (pHG) when caused by any diseases affecting the testes, or as secondary (sHG) when due to a pituitary or hypothalamic dysfunction. Both fertility and testosterone (T) can be theoretically restored in sHG by removing the precipitating cause and/or by appropriate endocrine therapy. Conversely, only T treatment can be offered to patients with pHG. Symptoms and signs are quite similar independent of the underlying causes. Conversely, the phenotype of the hypogonadal patient is more often affected by the age of hypogonadism onset. Late-onset hypogonadism (LOH) that occurs in adulthood is probably the most common form of HG. In this chapter, the criteria defining LOH and the available T formulations along with their outcomes and main important side effects are analyzed in detail

    Microwave Assisted Synthesis, Characterization and Antibacterial Study of Some Novel Schiff's Bases, Thaizolidinone and Chalcone Compounds Derived from Mefenamic Acid

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    This work involves synthesis of some new heterocyclic compounds including thaizolidinone compounds. The new Schiff bases derived from mefenamic acid, which was synthesized by microwave irradiation of mefenamic acid with hydrazine hydrate in absolute ethanol and this amino compound condensation with different aromatic aldehydes in absolute ethanol. Thaizolidinone compounds were synthesized by cycloaddition reaction of mercapto acetic acid to imine group of Schiff bases in dry benzene. The new chalcone derivatives synthesized by the reaction aldehyde with their compounds.  M.P., TLC, CHN, UV, FTIR and NMR spectroscopy has characterized all the synthesized compounds. The biological screening data of the synthesized compounds were also studied. Keywords: Schiff bases, thaizolidinone, chalcone, antibacterial

    Anthropogenic sinkholes of the city of Naples, Italy: an update

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    In recent years, the study of anthropogenic sinkholes in densely urbanized areas has attracted the attention of both researchers and land management entities. The city of Naples (Italy) has been frequently affected by processes generating such landforms in the last decades: for this reason, an update of the sinkhole inventory and a preliminary susceptibility estimation are proposed in this work. Starting from previous data, not modified since 2010, a total of 270 new events occurred in the period February 2010–June 2021 were collected through the examination of online newspapers, local daily reports, council chronicle news and field surveys. The final consistence of the updated inventory is of 458 events occurred between 1880 and 2021, distributed through time with an increasing trend in frequency. Spatial analysis of sinkholes indicates a concentration in the central sector of the city, corresponding to its ancient and historic centre, crossed by a dense network of underground tunnels and cavities. Cavity-roof collapse is confirmed as one of the potential genetic types, along with processes related to rainfall events and service lines damage. A clear correlation between monthly rainfall and the number of triggered sinkholes was identified. Finally, a preliminary sinkhole susceptibility assessment, carried out by Frequency Ratio method, confirms the central sector of city as that most susceptible to sinkholes and emphasizes the predisposing role of service lines, mostly in the outermost areas of the city

    An innovative method to produce green table olives based on "pied de cuve" technology

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    The technology of "pied de cuve" (PdC) is applied in food process only to produce wines with an enriched community of pro-technological yeasts. PdC promotes the growth of the desirable microbial strains in a small volume of grape must acting as a starter inoculums for higher volumes. The aim of the present work was to investigate the use of partially fermented brines, a technology known as PdC, developed with lactic acid bacteria (LAB) on the microbiological, chemical and sensory characteristics of green fermented table olives during two consecutive campaigns. The experimental plan included two trials based on different PdCs: trial A, PdC obtained with Lactobacillus pentosus OM13; trial B, PdC obtained through a spontaneous fermentation. Two control additional trials without PdC were included for comparison: trial C, spontaneous fermentation; trial D, direct inoculation of L. pentosus OM13. The use of PdCs favoured the rapid increase of LAB concentrations in both trials A and B. These trials showed levels of LAB higher than trial C and almost superimposable to that of trial D. Trial B was characterized by a certain diversity of L. pentosus strains and some of them dominated the manufacturing process. These results indicated PdC as a valuable method to favour the growth of autochthonous L. pentosus strains. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) visibly discriminated olive processes fermented with the two experimental PdCs. Interestingly, on the basis of microbial and pH variables, both approaches showed that the olives produced with PdC technology are closely related to those of trial D, with the advantages of reducing the amount of starter to inoculate (trial A) and a higher LAB biodiversity (trial B). Volatile organic compound (VOC) composition and sensory analysis showed trials A and B different from the trials with no PdC added, in both years. Furthermore, the trial B showed the highest scores of green olive aroma and taste complexity. Spoilage microorganisms were estimated at very low levels in all trials. Undesired off-odours and off-flavours were not revealed at the end of the process

    A dedicated electric oven for characterization of thermoresistive polymer nanocomposites

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    AbstractThe construction, characterization and control of an electric oven dedicated to the study of thermoresistive polymer nanocomposites is presented. The oven is designed with a heating plate capable of reaching 300°C with a resolution of 0.3°C and an area of uniform temperature of 3.8cm×2.5cm. The temperature is regulated by means of a discrete proportional–integral–derivative controller. A heat transfer model comprising three coupled non-linear differential equations is proposed to predict the thermal profiles of the oven during heating and cooling, which are experimentally verified. The oven is used for thermoresistive characterization of polymer nanocomposites manufactured from a polysulfone polymer and multiwall carbon nanotubes

    Effect of Glucose and Inactivated Yeast Additions on the Fermentation Performances of Lactiplantibacillus pentosus OM13 during the Production of Nocellara del Belice Table Olives

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    The use of selected strains of lactic acid bacteria is necessary to produce fermented table olives with high hygiene and quality standards at the industrial level. A current tendency is the use of fermentation adjuvants (nutrients and activators) that can satisfy the nutritional needs of starter strains. In this study, five experimental protocols, different for nutrient and activator presence and addition of Lactiplantibacillus pentosus OM13 in freeze-dried form and after acclimatisation, were tested with the aim of improving the fermentation performances of the commercial starter. The trial inoculated with the starter strain acclimatised in the presence of nutrients and activator showed the most rapid acidification during the first phase of fermentation (third to ninth day), registering a pH loss of 3.40 units. The addition of adjuvants positively influences starter dominance (>89%) and rapid colonisation (>7 Log CFU/mL from third d) by indirectly limiting the presence of undesirable microorganisms. The analysis of volatile organic compounds revealed the presence of 32 chemicals distributed differently in each trial. Sensory evaluation showed that table olives produced with the different treatments were characterised by low bitterness, acidity, and absence of unpleasant odours/flavours. Control production showed slower acidification kinetics and lower sensory pleasantness than the other trials
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