Study on the applicability of high-pressure homogenization for the production of banana juices

The aim of this preliminary study was to evaluate the potential applicability of high-pressure homogenization (HPH) for the production of banana juices. To this purpose, a prototype equipment working up to 400 MPa and a lab-scale homogenizer working up to 150 MPa were used. Temperature, microbial load, pectate lyase activity, colour and viscosity of the samples homogenized at increasing pressure were evaluated. Pressures higher than 200 MPa were needed to obtain 4 log unit reduction of total mesophilic bacteria and pectate lyase inactivation. Following HPH, banana juice resulted brighter and less viscous than the untreated one. Data suggest that HPH treatments could be a reliable technological alternative to conventional heat treatments for the production of added-value fruit juices. However, the homogenization design could play a critical role in affecting the product quality attributes. In fact, homogenization performed at the same operative pressure by using different equipment leads to different effects on product quality.     

Emulsification of Simulated Gastric Fluids Protects Wheat α-Amylase Inhibitor 0.19 Epitopes from Digestion

Wheat α-amylase inhibitors (α-AIs) are known anti-nutritional factors, respiratory allergens, and they can sporadically cause food allergy. α-AIs are therefore expected to reach the enteric mucosae in an immunologically active form, but information on their stability to gastric digestion is not available. Resistance to pepsinolysis is nonetheless a key factor for any food allergen. We therefore investigated whether α-AIs could resist pepsin digestion in simulated gastric fluids (SGF) and in emulsified SGF, the latter simulating more realistically the multi-phase nature of stomach bolus. Since α-AIs comprise a huge family of proteins, we investigated 0.19 α-AI as a prominent member. The digestion patterns were analyzed by immunoblotting using anti-0.19 polyclonal antibodies and sera from wheat allergic patients sensitized to 0.19 α-AI. The results show that the immune epitopes of α-AI are detectable up to 120 min of digestion in emulsifying conditions. Intra-molecular disulfide bonds and, in particular, emulsification were found to be crucial factors for protein stability. The results show that 0.19 α-AI must be considered a potential food allergen.     

Evidence for the existence of a specific g protein-coupled receptor activated by guanosine

Guanosine, released extracellularly from neurons and glial cells, plays important roles in the central nervous system, including neuroprotection. The innovative DELFIA Eu‐GTP binding assay was optimized for characterization of the putative guanosine receptor binding site at rat brain membranes by using a series of novel and known guanosine derivatives. These nucleosides were prepared by modifying the purine and sugar moieties of guanosine at the 6‐ and 5′‐positions, respectively. Results of these experiments prove that guanosine, 6‐thioguanosine, and their derivatives activate a G protein‐coupled receptor that is different from the well‐characterized adenosine receptors.     

Neuropeptide S receptor: recent updates on nonpeptide antagonist discovery

Neuropeptide?S (NPS) is a 20-amino acid peptide of great interest due to its possible involvement in several biological processes, including food intake, locomotion, wakefulness, arousal, and anxiety. Structure-activity relationship studies of NPS have identified key points for structural modifications with the goal of modulating NPS receptor (NPSR) agonist activity or achieving antagonism at the same receptor. Only limited information is available for nonpeptide NPSR antagonists. In the last year, several studies have been reported in literature which present various series of small molecules as antagonists of this receptor. The results allow a comparison of the structures and activities of these molecules, leading to the design of new ligands with increased potency and improved pharmacological and pharmacokinetic profiles. This work presents a brief overview of the available information regarding structural features and pharmacological characterization of published nonpeptide NPSR antagonists.     

Induction of grape botrytization during withering affects volatile composition of Recioto di Soave, a “passito”-style wine

The influence of noble rot on the quality of Recioto di Soave, a “passito” sweet white wine, is greatly variable depending on the occurrence of favourable seasonal conditions for the mould infection. Botrytized wines were produced from grapes inoculated with conidia suspensions to evaluate the effects of noble rot on volatile compounds profile of Recioto di Soave wine. Different development stages of Botrytis cinerea and degree of grape withering were ascertained by must analysis. Several volatile components were involved in marked changes depending on the infection and grape withering level. Fruity esters, carbonyl compounds, phenols, lactones and acetamides greatly changed among botrytized wines. The results demonstrated that the level of B. cinerea infection and the degree of grape withering exert considerable influence on the volatile composition of this sweet wine. Strain-dependent effects were also preliminary ascertained. The process of induction of grape botrytization presented in this study could be recommendable for the industrial production of botrytized Recioto di Soave wine.     

Contrasting approaches to the generation of environmental improvement options for production systems

This article reviews two common types of improvement tools presently used in industry to identify opportunities to prevent or at least to reduce the environmental impacts of production systems and processes. Despite their proven ability to result in appropriate environmental improvement options in different industry sectors, their successful application is hampered by the fact that these tools do not take the specific causes of the environmental impacts of the production process into account, i.e. the question of which process features cause the environmental impacts of the production process is not raised nor is the flexibility for change of the production system taken into consideration. This paper sets the stage for a new generation of improvement tools, based on an environmental diagnosis of the production system. The diagnosis aims to result in a thorough understanding of the production system to guide and drive the identification of environmental improvement options that specifically target process-, product-, and site-specific environmental conditions. Alternative ways to develop such a diagnostic approach on the basis of presently used tools are being explored, and a synthesis thereof is proposed to achieve synergy between these contrasting approaches. Received: 7 August 2000 / Accepted: 8 November 2000     

The Tetragonal to Orthorhombic Structural Phase Transition in Multiband FeAs-based Superconductors

We report the temperature-dependent x-ray powder diffraction of the FeAs-based superconductors in the range between 300 and 95 K. In the case of NdOFeAs we have detected the structural phase transition from the tetragonal phase, with P4/nmm space group, to the orthorhombic phase, with Cmma space group, over a broad temperature range from 150 to 120 K, centered at T ₀∼137 K. This transition is reduced, by about ∼30 K, by the internal chemical pressure going from LaOFeAs to NdOFeAs. On the contrary, the superconducting critical temperature increases from 27 to 51 K going from LaOFeAs to NdOFeAs doped samples. The FeAs layers in all undoped “1111” and “122” systems suffer a tensile misfit strain. The tensile misfit strain is reduced in “1111” and in “122” samples and at optimum doping the misfit strain is close to zero. This result shows that the normal striped orthorhombic Cmma phase competes with the superconducting tetragonal phase. In the orthorhombic clusters the charges can move only along the stripes in the b direction and are localized by the magnetic interaction.     

Diazoxide Needs Mitochondrial Connexin43 to Exert Its Cytoprotective Effect in a Cellular Model of CoCl2-Induced Hypoxia

Hypoxia is the leading cause of death in cardiomyocytes. Cells respond to oxygen deprivation by activating cytoprotective programs, such as mitochondrial connexin43 (mCx43) overexpression and the opening of mitochondrial K_ATP channels, aimed to reduce mitochondrial dysfunction. In this study we used an in vitro model of CoCl₂-induced hypoxia to demonstrate that mCx43 and K_ATP channels cooperate to induce cytoprotection. CoCl₂ administration induces apoptosis in H9c2 cells by increasing mitochondrial ROS production, intracellular and mitochondrial calcium overload and by inducing mitochondrial membrane depolarization. Diazoxide, an opener of K_ATP channels, reduces all these deleterious effects of CoCl₂ only in the presence of mCx43. In fact, our results demonstrate that in the presence of radicicol, an inhibitor of Cx43 translocation to mitochondria, the cytoprotective effects of diazoxide disappear. In conclusion, these data confirm that there exists a close functional link between mCx43 and K_ATP channels.