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

Pregnancy vaccination predictive factors and uptake profiles among Italian women: A cross-sectional survey study on a large population

Objectives: To assess influenza and Tdap (tetanus, diphtheria, pertussis) vaccine coverage during pregnancy, explore key socioeconomic and maternity pathway-related predictors of vaccination, and detect specific patterns of vaccination uptake. Methods: The authors cross-sectionally analyzed self-reported data obtained from the systematic survey on the maternity pathways of Tuscany. They selected all pregnant women that completed from March 2019 to June 2022 the third-trimester questionnaire (n = 25 160), which included two dichotomous items on influenza and Tdap vaccination, as well as socioeconomic and pathway-related questions. Multilevel logistic models were performed to assess vaccination predictors and cluster analysis to identify vaccination patterns. Results: Vaccination coverage was higher for pertussis (56.5%) than for influenza (18.9%). The main predictors of vaccination were high socioeconomic status, attending private gynecologists, and receiving vaccine information. Three clusters were identified: cluster 1 included women receiving both Tdap and influenza vaccines; cluster 2 included women receiving no vaccinations; and cluster 3 included women receiving only the pertussis vaccine. Although women from cluster 3 were of middle to low education status, vaccine information was the main adherence determinant also in this group. Conclusions: Health workers and policymakers should focus on groups of pregnant women less prone to vaccination to promote vaccination information and encourage wider uptake and coverage

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

Screening dell\u2019attivit\ue0 \u3b2-glucosidasica in ceppi di Saccharomyces spp. isolati da mosto

Nei lieviti, l'attivit\ue0 della \u3b2-glucosidasi \ue8 stata ampiamente descritta, specialmente nelle specie non-Saccharomyces, mentre questa attivit\ue0 risulta essere poco evidente nei ceppi appartenente al genere Saccharomyces. In enologia l'attivit\ue0 \u3b2-glucosidasica \ue8 un carattere di interesse, in quanto correlata al miglioramento dell'espressione aromatica dei vini. Infatti, il suddetto enzima va ad agire sulla classe dei composti aromatici terpenici. Tali composti si trovano sotto forma di coniugati \u3b2-glucosidici nelle variet\ue0 d'uva aromatiche come Moscato e Gew\ufcrztraminer. La forma coniugata \ue8 tuttavia non volatile e, conseguentemente, non aromatica. La presente ricerca fornisce nuove conoscenze sull'attivit\ue0 della \u3b2-glucosidasi in ceppi di interesse enologico appartenenti alle specie Saccharomyces cerevisiae e Saccharomyces uvarum. In particolare, 75 ceppi, isolati da mosto d\u2019uva refrigerato e appartenenti alle due specie suddette, sono stati valutati relativamente all\u2019attivit\ue0 \u3b2-glucosidasica, sia dal punto di vista qualitativo che quantitativo. Lo screening qualitativo in piastra, mediante l\u2019uso di substrati cromogenici, quali esculina e arbutina, ha messo in evidenza un maggior grado di positivit\ue0 dei test provati per i ceppi della specie S. uvarum rispetto a quelli della specie S. cerevisiae. Successivamente, sui ceppi positivi ad entrambi i due precedenti test, \ue8 stato condotto un test quantitativo dell\u2019attivit\ue0 \u3b2-glucosidasica, mediante il metodo spettrofotomentrico basato sull\u2019idrolisi del p\u2010nitrophenyl\u2010\u3b2\u2010D\u2010glucopyranoside (p\u2010NPG). La valutazione \ue8 stata effettuata su tre diverse frazioni dei campioni analizzati: il surnatante, il lisato cellulare e le cellule intere. I risultati ottenuti hanno messo in evidenza che l'attivit\ue0 enzimatica \ue8 principalmente associata alle cellule intere. Inoltre, tre ceppi di S. uvarum, CRY14, VA42 and GRAS14, hanno mostrato una pronunciata attivit\ue0 \u3b2-glucosidasica (Bonciani et al., 2018). Questi ceppi potrebbero essere sfruttati per la loro potenziale capacit\ue0 di migliorare i profili aromatici del vino. Pi\uf9 in generale, lo studio apre un nuovo e promettente campo della ricerca dell'attivit\ue0 \u3b2-glucosidasica in ceppi appartenenti alla specie S. uvarum, fin'ora poco esplorata. Reference Bonciani T., De Vero L., Giannuzzi E., Verspohl A. and Giudici P. (2018). Qualitative and quantitative screening of the \u3b2\u2010glucosidase activity in Saccharomyces cerevisiae and Saccharomyces uvarum strains isolated from refrigerated must. Lett. Appl. Microbiol. Accepted Manuscript. doi:10.1111/lam.1289

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