Aerobic industrial processing of Empeltre cv. natural black olives and product characterisation

The fermentation of natural black olives is currently carried out under anaerobic conditions. This work investigates the aerobic fermentation of this product in tanks containing 16 000 kg of Empeltre olives during two seasons. The microorganisms in brines were yeasts in all cases, whereas lactic acid bacteria growth was only observed in some tanks. Consequently, the pH during fermentation was in most cases higher than recommended 4.3 units. However, the Empeltre olive brines displayed bactericidal effect against Salmonella enterica, Sthapylococcus aureus, Escherichia coli and Listeria monocytogenes, with a 5 log population drop in one or 24 h depending on the brine age so that these olive brines are a harsh environment for the growth of these pathogens. It was found HyEDA as the major phenolic compound in both brine and olive pulp at the beginning of fermentation that slowly hydrolysed into hydroxytyrosol that reached a concentration up to 1500 mg kg⁻¹.     

Factors affecting the changes in texture of dressed ("aliñadas") olives

The effect of the natural components of dressing during the conservation of olives on their texture was studied. Significant differences in texture between preparations with and without dressing were detected, although the texture in both preparations continued to diminish with time of conservation until the difference between textures was eliminated. These facts suggest that the enzymes coming from the constituents of the dressing (garlic, lemon, etc), as well as those endogenous enzymes in the olive fruit itself influence the changes in the texture, the olive becoming more susceptible to dressing and to enzymatic action as the stage of maturation progresses. Changes in the composition of polysaccharides and significant decreases in texture were related. Degradation of important polysaccharides in the structure of cell walls, such as !-cellulose, carbonate-soluble pectin and 4% KOH-soluble hemicelluloses were detected. This noticeable degradation could be explained perfectly by the combined action of the cell wall degrading enzymes, cellulase and polygalacturonase, present.     

Absorption of sorbic and benzoic acids in the flesh of table olives

The distribution of sorbic and benzoic acids in the different phases of table olives was studied. To a large extent, these preservatives accumulated in the oil phase of fruits stored in acid conditions, as well as in juice and other tissue components. Thus, around 20–30% of the benzoic acid in olives was found in the juice phase, 30–50% in the oil phase and 30–40% in the rest of the olive flesh. Experiments carried out with black ripe olives revealed that an increase in pH of the medium gave rise to a decrease in the absorption phenomenon in whole olives and in the oil phase. As a consequence of this effect, benzoic acid could be leached from stored black ripe olives during the darkening process, although the calcium content of fruits greatly influenced the diffusion phenomenon. The results obtained in this study are important for future legal limitations of these preservatives in table olives and inhibition capacity of them in commercial table olives.     

Control of Listeria monocytogenes in boned dry-cured ham by E-beam treatment

Boning of dry-cured hams involves additional handling which increases the risk of contamination with Listeria monocytogenes. This work studies the ability of E-beam to eliminate this pathogen from boned dry-cured ham (BDH). The destruction kinetics of four L. monocytogenes strains (S2, S4-2, S12-1, and S7-2) and L. innocua NCTC 11288 as a surrogate were determined at doses up to 3 kGy. L. innocua and L. monocytogenes S4-2 were the most radioresistant (D-value = 0.55 kGy). E-beam penetration was studied in blocks extracted from BDH and irradiated with 2–6 kGy. The bilateral treatment of 2 kGy allows the required dose (1.32 kGy) to be absorbed in the innermost part of the block to achieve the food safety objective of “zero tolerance” for this microorganism. This listericidal treatment was also confirmed in whole BDH intentionally contaminated with L. innocua. The sensory analysis of irradiated BDH showed off-odors that were imperceptible after 15 days of storage at 4°C.     

Comparative Binding Energy (COMBINE) Analysis for Understanding the Binding Determinants of Type II Dehydroquinase Inhibitors

Herein we report comparative binding energy (COMBINE) analyses to derive quantitative structure–activity relationship (QSAR) models that help rationalize the determinants of binding affinity for inhibitors of type II dehydroquinase (DHQ2), the third enzyme of the shikimic acid pathway. Independent COMBINE models were derived for Helicobacter pylori and Mycobacterium tuberculosis DHQ2, which is an essential enzyme in both these pathogenic bacteria that has no counterpart in human cells. These studies quantify the importance of the hydrogen bonding interactions between the ligands and the water molecule involved in the DHQ2 reaction mechanism. They also highlight important differences in the ligand interactions with the interface pocket close to the active site that could provide guides for future inhibitor design.     

Molecular Approach to Electrochemically Switchable Monolayer MoS2 Transistors

As Moore's law is running to its physical limit, tomorrow's electronic systems can be leveraged to a higher value by integrating “More than Moore” technologies into CMOS digital circuits. The hybrid heterostructure composed of two-dimensional (2D) semiconductors and molecular materials represents a powerful strategy to confer new properties to the former components, realize stimuli-responsive functional devices, and enable diversification in “More than Moore” technologies. Here, an ionic liquid (IL) gated 2D MoS₂ field-effect transistor (FET) with molecular functionalization is fabricated. The suitably designed ferrocene-substituted alkanethiol molecules not only improve the FET performance, but also show reversible electrochemical switching on the surface of MoS₂. Field-effect mobility of monolayer MoS₂ reaches values as high as ≈116 cm² V⁻¹ s⁻¹ with I_on/I_off ratio exceeding 10⁵. Molecules in their neutral or charged state impose distinct doping effect, efficiently tuning the electron density in monolayer MoS₂. It is noteworthy that the joint doping effect from IL and switchable molecules results in the steep subthreshold swing of MoS₂ FET in the backward sweep. These results demonstrate that the device architecture represents an unprecedented and powerful strategy to fabricate switchable 2D FET with a chemically programmed electrochemical signal as a remote control, paving the road toward novel functional devices.     

The Literature of Bibliometrics,Scientometrics, and Informetrics

Since Vassily V. Nalimov coined the term ‘scientometrics’ in the 1960s, this term has grown in popularity and is used to describe the study of science: growth, structure, interrelationships and productivity. Scientometrics is related to and has overlapping interests with bibliometrics and informetrics. The terms bibliometrics, scientometrics, and informetrics refer to component fields related to the study of the dynamics of disciplines as reflected in the production of their literature. Areas of study range from charting changes in the output of a scholarly field through time and across countries, to the library collection problem of maintaining control of the output, and to the low publication productivity of most researchers. These terms are used to describe similar and overlapping methodologies. The origins and historical survey of the development of each of these terms are presented. Profiles of the usage of each of these terms over time are presented, using an appropriate subject category of databases on the DIALOG information service. Various definitions of each of the terms are provided from an examination of the literature. The size of the overall literature of these fields is determined and the growth and stabilisation of both the dissertation and non-dissertation literature are shown. A listing of the top journals in the three fields are given, as well as a list of the major reviews and bibliographies that have been published over the years. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.