Influence of the pH of Chardonnay must on malolactic fermentation induced by bacteria co-inoculated with yeasts

Research Note

Evaluating the Efficacy of Lysozyme Against Lactic Acid Bacteria Under Different Winemaking Scenarios

This study evaluated the efficacy of lysozyme in winemaking to control lactic acid bacteria (LAB). In a wineryvinification, indigenous LAB were partially and completely inhibited when lysozyme was added to red and whitegrape must respectively. This result was confirmed by using two selected strains of Lactobacillus brevis andOenococcus oeni to contaminate the grape must. In the red wine microvinification, the cell population decreasedonly temporarily and malolactic fermentation terminated at different times, depending on the grape must pH andlysozyme dosage. In the white wine microvinification, cell mortality rates differed according to lysozyme dosagerather than pH values. During the fermentation, lysozyme activity was stable or decreased, depending on theabsence or presence of grape must respectively. The study highlighted that lysozyme efficacy is strongly affected bythe type of vinification

Interactions between Saccharomyces and Oenococcus oeni strains from Amarone wine affect malolactic fermentation and wine composition

Research Note

Bacterial Inoculation Strategies for the Achievement of Malolactic Fermentation in High-alcohol Wines

The purpose of this work was to study the induction of malolactic fermentation (MLF) in a wine that does not oftensupport malic acid deacidification because of its high alcohol content. Amarone wine, known for its high alcoholcontent, served as a model. Simultaneous and sequential alcoholic and malolactic fermentation (AF/MLF) wereconducted by direct inoculation of bacteria, which resulted in successful MLF in wines containing approximately16% (v/v) alcohol. At higher ethanol contents, stuck MLF occurred because of growth inhibition. To overcomethis technological problem, the performance of bacteria was tested in wine containing approximately 17% (v/v)ethanol using a starter preparation consisting of cells acclimatised in a wine-water solution (1:1) for 24 h and 48h respectively. Total l-malic acid depletion was recorded when the bacterial cells that had been acclimatised for48 h were inoculated simultaneously with yeast to conduct AF. The method by which the bacterial cultures areprepared and the time of inoculation affects the efficacy of MLF in high-alcohol wines. The inoculation of yeastswith acclimatised bacteria before AF seems to be a valid strategy to obtain complete MLF in high-alcohol wines

Correlating Noble Rot Infection of Garganega Withered Grapes with Key Molecules and Odorants of Botrytized Passito Wine

Experimental passito wines with dierent percentages of naturally noble-rotten grapes of the Garganega variety were analyzed to evaluate key molecules and odorants related to the typical aroma and sensory profile of botrytized passito wine. Remarkable changes in the concentration of 1-octen-3-ol, 4-terpineol, benzaldehyde, N-(3-methylbutyl)acetamide, and sherry lactone 1 and 2 were observed between sound and noble-rotten wines. Wines were perceived to be dierent for floral, honey, figs, apricot, and caramel scents. By partial least square regression these descriptors were well correlated to samples. An important positive contribution of sherry lactones, N-(3-methylbutyl)acetamide, vanillin, benzaldehyde, and -butyrolactone to honey, apricot, and caramel was observed. It is conceivable that oxidative eects of Botrytis cinerea infection play an important role in the genesis of these chemical and sensory aroma markers. This study provides a predictive tool for winemakers that use natural grape withering to produce wines whose aroma profile is not standardized due to the seasonal variation of noble rot incidence

Immobilization of Monolayer Protected Lipophilic Gold Nanorods on a Glass Surface

We present a novel process of immobilization of gold nanorods (GNRs) on a glass surface. Wedemonstrate that by exploiting monolayer protection of the GNRs, their unusual opticalproperties can be completely preserved. UV–visible spectroscopy and atomic forcemicroscopy analysis are used to reveal the optical and morphological properties of monolayerprotected immobilized lipophilic GNRs, and molecular dynamics simulations are used toelucidate their surface molecule arrangements

Hungry brains: A meta-analytical review of brain activation imaging studies on food perception and appetite in obese individuals

The dysregulation of food intake in chronic obesity has been explained by different theories. To assess their explanatory power, we meta-analyzed 22 brain-activation imaging studies. We found that obese individuals exhibit hyper-responsivity of the brain regions involved in taste and reward for food-related stimuli. Consistent with a Reward Surfeit Hypothesis, obese individuals exhibit a ventral striatum hyper-responsivity in response to pure tastes, particularly when fasting. Furthermore, we found that obese subjects display more frequent ventral striatal activation for visual food cues when satiated: this continued processing within the reward system, together with the aforementioned evidence, is compatible with the Incentive Sensitization Theory. On the other hand, we did not find univocal evidence in favor of a Reward Deficit Hypothesis nor for a systematic deficit of inhibitory cognitive control. We conclude that the available brain activation data on the dysregulated food intake and food-related behavior in chronic obesity can be best framed within an Incentive Sensitization Theory. Implications of these findings for a brain-based therapy of obesity are briefly discussed

Motor imagery training speeds up gait recovery and decreases the risk of falls in patients submitted to total knee arthroplasty

With Motor imagery (MI), movements are mentally rehearsed without overt actions; this procedure has been adopted in motor rehabilitation, primarily in brain-damaged patients. Here we rather tested the clinical potentials of MI in purely orthopaedic patients who, by definition, should maximally benefit of mental exercises because of their intact brain. To this end we studied the recovery of gait after total knee arthroplasty and evaluated whether MI combined with physiotherapy could speed up the recovery of gait and even limit the occurrence of future falls. We studied 48 patients at the beginning and by the end of the post-surgery residential rehabilitation program: half of them completed a specific MI training supported by computerized visual stimulation (experimental group); the other half performed a non-motoric cognitive training (control group). All patients also had standard physiotherapy. By the end of the rehabilitation, the experimental group showed a better recovery of gait and active knee flexion-extension movements, and less pain. The number of falls or near falls after surgery was significantly lower in the experimental group. These results show that MI can improve gait abilities and limit future falls in orthopaedic patients, without collateral risks and with limited costs