Sensory analysis of traditional balsamic vinegars: current state and future perspectives

Quality evaluation of traditional balsamic vinegar (TBV) is primarily based on sensory analysis. For every TBV batch, official sensory panels give a final score, which determines its assessment into quality and price categories. Therefore, an effective and objective sensory analysis is a core aspect in TBV production and marketing and it should fulfill at least two conditions: i) the panelists have been properly trained on the TBV features; ii) the panelists have to be free from any psychological and physical conditions which might affect human judgments. Traditionally, a panel of trained members assesses the TBV sensory attributes evaluating visual, olfactory, gustatory and trigeminal features at the same time. The result is that visual appearance significantly affects the subsequent stages of the sensory analysis, and even the olfactory and gustatory sensations will greatly affect each other. The aim of this work was to review the procedures for the sensory analysis of TBV and to define a set of TBV attributes. A new assessment questionnaire has been proposed to establish the appropriate sensory vocabulary for a complete description of TBV sensory properties

High-glutathione producing yeasts obtained by genetic improvement strategies: a focus on adaptive evolution approaches for novel wine strains

Glutathione (GSH) is the most abundant non-protein thiol in living organisms. Due to its important antioxidant role, it is widely used in medicine, as a food additive, and in the cosmetic industry. Recently, GSH has received growing attention in winemaking because of its ability to control oxidative spoilage damage and to protect various aromatic compounds. Indeed, GSH concentration in wine is highly variable and several factors are involved in its regulation, ranging from grape must to yeast fermentation activity. This short review aims at highlighting the common genetic strategies, useful for obtaining wine yeasts with enhanced GSH production, paying particular attention to the adaptive evolution approaches. Moreover, other strategies, such as random mutagenesis, metabolic engineering and hybridization have been briefly reviewed with a stress on both their strengths and weaknesses in terms of actual feasibility and acceptance by wine consumers

the flavor and taste of cereal chinese vinegars

A lexicon for describing Chinese cereal vinegars (CCVs) was developed using trained panels of tasters that defined and referenced 23 significant olfactory descriptors, in concert with taste and trigeminal sensation. The sensory analysis was performed on 27 samples, representative of the five well-known Chinese provinces producing vinegar: Shanxi, Jiangsu, Sichuan, Fujian and Tianjin. Several aromatic descriptors define the sensory lexicon, e.g.: licorice, chocolate, meat broth, toasted, walnut, yogurt, coffee; together with five basic tastes, such as acid, sweet, salty, umami and bitter; and four for trigeminal sensations, astringent, pungent, metallic, and piquant (spicy). This preliminary study will be useful to CCVs producers because this lexicon reliably differentiates and characterizes this kind of vinegar

Potential shallow aquifers characterization through an integrated geophysical method: multivariate approach by means of k-means algorithms

The need to obtain a detailed hydrogeological characterization of the subsurface and its interpretation for the groundwater resources management, often requires to apply several and complementary geophysical methods. The goal of the approach in this paper is to provide a unique model of the aquifer by synthesizing and optimizing the information provided by several geophysical methods. This approach greatly reduces the degree of uncertainty and subjectivity of the interpretation by exploiting the different physical and mechanic characteristics of the aquifer. The studied area, into the municipality of Laterina (Arezzo, Italy), is a shallow basin filled by lacustrine and alluvial deposits (Pleistocene and Olocene epochs, Quaternary period), with alternated silt, sand with variable content of gravel and clay where the bottom is represented by arenaceous-pelitic rocks (Mt. Cervarola Unit, Tuscan Domain, Miocene epoch). This shallow basin constitutes the unconfined superficial aquifer to be exploited in the nearly future. To improve the geological model obtained from a detailed geological survey we performed electrical resistivity and P wave refraction tomographies along the same line in order to obtain different, independent and integrable data sets. For the seismic data also the reflected events have been processed, a remarkable contribution to draw the geologic setting. Through the k-means algorithm, we perform a cluster analysis for the bivariate data set to individuate relationships between the two sets of variables. This algorithm allows to individuate clusters with the aim of minimizing the dissimilarity within each cluster and maximizing it among different clusters of the bivariate data set. The optimal number of clusters "K", corresponding to the individuated geophysical facies, depends to the multivariate data set distribution and in this work is estimated with the Silhouettes. The result is an integrated tomography that shows a finite number of homogeneous geophysical facies, which therefore permits to distinguish and interpret the porous aquifer in a quantitative and objective way

Applicazioni dei batteri acetici

I batteri acetici sono microrganismi aerobi stretti che hanno un uso consolidato nella produzione di aceto. Oltre che per la produzione di aceto sono impiegati per la produzione di molti composti ad alto interesse biotecnologico, come ad esempio intermedi di sintesi della vitamina C (acido 2-cheto- L-gulonico), acidi organici come l’acido gluconico e diidrossiacetone. In tempi recenti è stata sfruttata la loro capacità di produrre cellulosa e ne è stato proposto l’impiego nella produzione di alimenti e bevande prebiotiche grazie alla capacità di produzione di levani esopolisaccaridici. Alla luce di queste evidenze risulta interessante un’analisi di diverse applicazioni industriali dei batteri acetici per evidenziare le potenzialità di sviluppo legate ad aspetti metabolici ancora poco sfruttati

Lieviti enologici alto-produttori di glutatione ottenuti mediante strategia basata sull'evoluzione adattativa

Le strategie di evoluzione adattativa per il miglioramento genetico dei lieviti, sono ampiamente utilizzate in campo enologico. I vantaggi di queste strategie sono quelli di non introdurre geni ricombinanti estranei nel genoma dei microrganismi e di non richiedere una pregressa conoscenza dei geni coinvolti nell’espressione dei fenotipi desiderati. Infatti, sottoponendo i microrganismi a colture seriali o continue per diverse generazioni, in presenza di una specifica pressione selettiva, si selezionano i ceppi evoluti esprimenti il carattere d’interesse. Tuttavia, poiché lo screening dei microrganismi evoluti richiede necessariamente l’espressione di fenotipi selezionabili, ossia facilmente riconoscibili, tali strategie non sono applicabili per l’ottenimento di caratteristiche enologiche legate a variazioni e ricombinazioni genetiche non direttamente selezionabili, come nel caso della elevata produzione di glutatione (GSH), o di composti sensorialmente attivi. Ciò nonostante, questo limite è superabile individuando, nella pathway biosintetica del metabolita di interesse, uno o più step in cui applicare una pressione selettiva in modo da selezionare i ceppi evoluti potenzialmente in grado di esprimere il fenotipo desiderato. Questa strategia “evolution-based” è stata recentemente messa a punto e applicata per la selezione di ceppi di lievito alto produttori di GSH (De Vero et al., 2017). La strategia descritta si basa sulla formazione di ricombinanti attraverso la riproduzione sessuale e sulla successiva individuazione dei ricombinanti di interesse attraverso uno screening rapido e altamente selettivo basato sulla resistenza ad elevate concentrazioni di molibdato, tossico per le cellule nella forma ionica esavalente. Infatti, il molibdato applicato come pressione selettiva, consente di selezionare i ceppi evoluti con un metabolismo alterato relativamente alla pathway di assimilazione dei solfati e della biosintesi del GSH. Tale strategia ha permesso di individuare, tra i ceppi evoluti, resistenti a elevate concentrazioni di molibdato, quelli migliorati per la formazione di GSH (Mezzetti et al., 2014, 2017; Bonciani et al., 2018). Reference Bonciani, T., De Vero, L., Mezzetti, F., Fay, J.C. and Giudici, P. (2018) A multi-phase approach to select new wine yeast strains with enhanced fermentative fitness and glutathione production. Appl Microbiol Biotechnol 102, 2269–2278. De Vero, L., Bonciani, T., Verspohl, A., Mezzetti, F. and Giudici, P. (2017) High-glutathione producing yeasts obtained by genetic improvement strategies: a focus on adaptive evolution approaches for novel wine strains. AIMS Microbiol 3, 155–170. Mezzetti, F., De Vero, L. and Giudici, P. (2014) Evolved Saccharomyces cerevisiae wine strains with enhanced glutathione production obtained by an evolution-based strategy. FEMS Yeast Res 14, 977–87. Mezzetti, F., Fay, J.C., Giudici, P. and De Vero, L. (2017) Genetic variation and expression changes associated with molybdate resistance from a glutathione producing wine strain of Saccharomyces cerevisiae. PLoS One 12, e0180814

Fast method for identifying inter- and intra-species Saccharomyces hybrids in extensive genetic improvement programs based on yeast breeding

Aims: The present work proposes a two-step molecular strategy to select inter- and intra-species Saccharomyces hybrids obtained by spore-to-spore mating, one of the most used methods for generating improved hybrids from homothallic wine yeasts. Methods and Results: As low spore viability and haplo-selfing are the main causes of failed mating, at first, we used colony screening PCR (csPCR) of discriminative gene markers to select hybrids directly on dissection plate and discard homozygous diploid colonies arisen from one auto-diploidized progenitor. Then, pre-selected candidates were submitted to recursive streaking and conventional PCR in order to discriminate between the hybrids with stable genomic background and the false-positive admixtures of progenitor cells both undergone haplo-selfing. csPCRs of internal transcribed spacer (ITS) 1 or 2, and the subsequent digestion with diagnostic endonucleases HaeIII and RsaI, respectively, were efficient to select six new Saccharomyces cerevisiae × Saccharomyces uvarum hybrids from 64 crosses. Intragenic minisatellite regions in PIR3, HSP150, and DAN4 genes showed high inter-strain size variation detectable by cost-effective agarose gel electrophoresis and were successful to validate six new intra-species S. cerevisiae hybrids from 34 crosses. Conclusions: Both protocols reduce significantly the number of massive DNA extractions, prevent misinterpretations caused by one or both progenitors undergone haplo-selfing, and can be easily implemented in yeast labs without any specific instrumentation. Significance and Impact of the Study: The study provides a method for the marker-assisted selection of several inter- and intra-species yeast hybrids in a cost-effective, rapid and reproducible manner

Influence of COVID-19 pandemic on self-reported urinary incontinence during pregnancy and postpartum: A prospective study

To explore how the COVID-19 pandemic influenced self-reported occurrence and severity of pregnancy-related urinary incontinence (UI) in the maternity pathways of Tuscany, Italy

Evaluation of Feynman integrals with arbitrary complex masses via series expansions

We present an algorithm to evaluate multiloop Feynman integrals with an arbitrary number of internal massive lines, with the masses being in general complex-valued, and its implementation in the \textsc{Mathematica} package \textsc{SeaSyde}. The implementation solves by series expansions the system of differential equations satisfied by the Master Integrals. At variance with respect to other existing codes, the analytical continuation of the solution is performed in the complex plane associated to each kinematical invariant. We present the results of the evaluation of the Master Integrals relevant for the NNLO QCD-EW corrections to the neutral-current Drell-Yan processes.Comment: 23 pages, 6 figures, 2 table