1,720,978 research outputs found
Saba, A Traditional Grape Molasse From Italy: Preliminary Analytical Characterization in Comparison With Fruit Pekmez
No full textFruit juice molasses, from grapes, mulberries and many other fruits, still represent important
traditional food products from the Balkans to the Caucasus, where they are indicated as
“pekmez” and its linguistic variants. In Italy, grapes have always been primarily used for wine
production. However, locally available resources were fully exploited in the past: saba or sapa
is a grape molasse obtained from unfermented juice slowly boiled for 24-48 hours, to obtain
a brownish, dense, very sweet syrup, storable for long time. Saba was used as a food, to
accompany cereal gruels or bread and, in less restricted situations, to season meat, cheese,
and to prepare particular pastries (“tortelli”) and jams (“savor”). After being almost forgotten,
in recent years saba has been resumed and is nowadays produced by local firms throughout
central Italy, where it is also the subject of local festivals.
In this work basic physical and chemical traits of several commercial saba samples from
different areas of Italy were analyzed and compared to samples of pekmez from Turkey and
Armenia and sladko from Bulgaria.
Saba dry matter and soluble solid content were respectively 68% and 63%, with high
variability among samples. Average titratable acidity was 14.8 g TAEs/L. Pekmez and sladko
showed lower variability and higher average dry matter and Brix with respect to Italian saba,
probably because of the tendency to reduce cooking time and temperature by some processors
in Italy, in order to increase yield and avoid the production of unwanted molecules.
Acidity was more stable and less affected by cooking, allowing to relate the differences among
samples to raw materials (species or cultivars). Titratable acidity and pH were more variable
in pekmez than in saba as a consequence of the very different raw materials used (mulberry,
carob, pomegranate, grapes). Pomegranate pekmez had very high acidity
Valutazione sensoriale di birre ottenute con ceppi di lievito diversi: un caso studio
No full textLa birra è una delle più diffuse e antiche bevande alcoliche al mondo. La Repubblica Ceca detiene il record mondiale di consumo annuo seguita da Germania, Austria e Irlanda. L’Italia registra un consumo di birra in rapida crescita, prevalentemente tra i giovani. Va sottolineato che il consumatore italiano tipico predilige ancora la qualità della bevanda piuttosto che la quantità e, sebbene il prezzo, in linea generale, sia un fattore molto importante, i consumatori attenti sono molto sensibili al processo di produzione, al marchio e, non ultime, alle proprietà sensoriali.
L’obiettivo del lavoro è stato valutare il profilo sensoriale di un prodotto ottenuto secondo un processo di produzione standard e utilizzando tre ceppi di lievito diversi, un ceppo Saccharomyces comunemente usato nel processo di birrificazione, e due ibridi ottenuti dall’incrocio tra ceppi Saccharomyces cerevisiae × Saccharomyces bayanus.
A tale scopo, nel corso della fase di addestramento, otto giudici su dodici sono stati scelti e 16 attributi sensoriali sono stati selezionati (4, 2 e 10 attributi sensoriali visivi, olfattivi e gustativi, rispettivamente).
L’analisi della varianza (ANOVA a due vie) con interazione ha permesso di evidenziare che i prodotti studiati si differenziano statisticamente per le caratteristiche sensoriali legate alla schiuma, oltre che per alcune caratteristiche gustative e olfattive (dolcezza, amarezza, aroma di cotto, corpo e frizzantezza, nota aromatica). I risultati ottenuti sono stati anche confermati dalla PCA (Principal Component Analysis), la quale ha permesso di separare i campioni in differenti cluster nello spazio definito dalle prime due componenti principali.
Sulla base dei risultati conseguiti, l’approccio sensoriale ha consentito di tracciare un adeguato profilo per ciascun campione di birra, evidenziando le differenze esistenti tra i campioni e dimostrando l’importanza di alcune scelte tecnologiche sulla qualità sensoriale dei prodotti
Ampelographic and chemical characterization of local grapes for ‘saba’ and ‘agresto’ in Reggio Emilia and Modena (Northern Italy)
No full textBACKGROUND ‘Saba’ and ‘agresto’ are traditional Italian products both based on unfermented grape juices that are concentrated by heating. The former is obtained from ripe grapes and the latter from unripe grapes. In this work, we have characterized the main red-skinned (Ancellotta, Fortana, Lambrusco di Sorbara, Lambrusco grasparossa, Lambrusco salamino and Uva Tosca) and white-skinned (Lugliatica, Spergola, Trebbiano di Spagna and Trebbiano modenese) cultivars used for ‘saba’ and ‘agresto’ production, focusing on the variability expressed by ampelographic traits, physical and chemical parameters and anthocyanin profile.
RESULTS The cultivars examined were effectively discriminated on the basis of their different composition profile by analysis of variance and principal component analysis. In particular, a peculiar anthocyanin profile was traced by absolute and relative values for each cultivar. The identification of the main anthocyanins of some local cultivars, their chemical characterization and their ampelographic description were one of the main achievements of this work.
CONCLUSION The use of red grapes to obtain ‘saba’ seems more rational for the presence of higher amounts of antioxidant substances. Ancellotta showed several factors interesting for ‘saba’ production, such as the very high anthocyanin content, including anthocyanin antioxidants. A more detailed investigation on ‘agresto’ technology is required
Data fusion of electronic eye and electronic tongue signals to monitor grape ripening
Full text linkTwo separate artificial sensors, an electronic eye (EE) and an electronic tongue (ET), were recently developed to monitor grape ripening based on the analysis of must. The aim of this research is to exploit the complementary information obtained by means of EE and ET sensing systems using different data fusion strategies, in order to develop an integrated device able to quickly and easily quantify the physico-chemical parameters that are used to assess phenolic ripeness. To this purpose, both low-level and mid-level data fusion approaches were investigated. Partial Least Squares (PLS) regression was applied to the fused data, with the aim of relating the information brought by the two sensors with twelve physico-chemical parameters measured on the must samples by standard analytical methods. The results achieved with mid-level data fusion outperformed those obtained using EE and ET separately, and highlighted that both the artificial sensors have made a significant contribution to the prediction of each one of the considered physico-chemical parameters
Pescabivona: caratterizzazione e specificità dei frutti nell’ambito del regime di qualità IGP
No full textPescabivona [Prunus persica (L.) Batsch] è una denominazione che raggruppa quattro ecotipi di pesche a polpa bianca autoctoni della zona centro-occidentale della Sicilia. Campioni dei quattro ecotipi di Pescabivona (Murtiddara, Bianca, Agostina e Settembrina) sono stati campionati a tre diverse altitudini durante tutta la stagione di raccolta da metà giugno a fine settembre. I quattro ecotipi sono stati caratterizzati mediante analisi chimiche e chimico-fisiche per determinare colore, peso, contenuto di solidi solubili, pH, acidità titolabile, acidi organici, zuccheri, sostanze aromatiche e fenoliche, capacità antiossidante e consistenza della polpa. Un panel di giudici addestrato ha, inoltre, tracciato il profilo sensoriale dei quattro ecotipi. I risultati sono stati impiegati nell’istanza di riconoscimento dell’Indicazione geografica protetta (IGP) che, ad oggi, ha ottenuto il parere favorevole dal Ministero delle Politiche Agricole Alimentari e Forestali e della Commissione Europea. Le elaborazioni statistiche dei dati hanno fatto emergere un quadro di sostanziale
omogeneità di composizione dei quattro ecotipi alle diverse altitudini
mettendo in luce un’elevata concentrazione di lattoni, molecole chiave per
le definizione dell’aroma. Il confronto dei quattro ecotipi di Pescabivona
e le principali pesche a polpa bianca diffuse sul mercato ha mostrato un
altro carattere peculiare: l’elevata consistenza della polpa specie per gli
ecotipi tardivi (Agostina e Settembrina) anche a livelli di maturazione di
consumo caratterizzati da un equilibrato valore del rapporto zuccheri/
acidi. In periodi dell’anno dove per le pesche, generalmente, si abbassa
il livello qualitativo, diventa non comune la possibilità di gustare frutti
consistenti a maturazione fisiologica e con profilo sensoriale apprezzabil
Valutazione di composti aromatici in vini ottenuti utilizzando differenti ceppi di lieviti Saccharomyces
No full textThe aromatic quality of wines depends on several factors. Some are intrinsic factors of the grape variety, others are linked to conditions such as climate and terroir, as well as the technological process of production. In this context, the yeasts have considerable importance. In oenology, there is a growing interest for the study of new yeast strains characterized by a good fermentative capacity and a favorable contribute to the sensory quality of wine. In this study, we compared six different Saccharomyces strains (3 S. cerevisiae e 3 S. bayanus), focusing on the fermentation performance and production of volatiles in white neutral wine from Trebbiano grapes. It is included in the study a new strain (ECA5TM) to deepen its fermentation ability and metabolite production in order to evaluate its possible employment in winemaking. A total of 39 compounds were quantified by gas chromatography (alcohols, higher alcohols, C6-alcohols, higher alcohol acetates, esters, fatty acids and terpenic compounds) in the wines obtained by fermentation with different yeats strains. The obtained results show that the tested strains are very similar regarding production of ethanol, glycerol, and aromatic compounds. However, ECA5TM strain showed a lower fermenting power, even though the ethanol content (% v/v) in the wine was similar to the others strains. Moreover, ECA5TM, as well as Lavlin 71B, positively influenced the aromatic profile, showing a higher content of some volatiles
Studio dei profili delle sostanze aromatiche glicosilate di vitigni (Vitis vinifera L) autoctoni dell’Emilia Romagna
No full textResearch on the glycosylated fraction of volatiles aims to investigate the mostly unexpressed aromatic potential of a grapevine. This reservoir of aromatic molecules is partially released during the production and aging of the wine and targeted technological interventions would allow the enhancement of the non aromatic grapevines. The analysis of eleven cultivars and accessions grown in Reggio Emilia highlighted that, apart from Malvasia di Candia aromatica, already studied for its rich component of monoterpenic compounds, Trebbiano di Spagna showed, as well, a very interesting profile with the presence of high concentrations of some monoterpenic alcohols. The other cvs showed a higher homogeneity of composition and a general lack of flavor with a few exceptions
Caratterizzazione sensoriale di Pescabivona e correlazione con i parametri compositivi
No full textPescabivona è il nome di una popolazione autoctona di pesche [Prunus persica (L.) Batch] della zona centro-occidentale della Sicilia, che riunisce quattro ecotipi. Questo studio rappresenta un approccio ad una complessiva valutazione sensoriale e compositiva dei frutti.
I dati dei profili sensoriali degli ecotipi sono stati messi in relazione a quelli ottenuti mediante determinazioni fisiche e chimiche, quali: colore, peso, consistenza della polpa, pH, °Brix, acidità titolabile (AT), rapporto °Brix/AT, acidi organici, zuccheri, componente aromatica (lattoni), flavan-3-oli, acidi idrossicinnamici e capacità antiossidante.
L’analisi sensoriale è stata eseguita dal panel dell’Organizzazione Nazionale Assaggiatori di Frutta (O.N.A.Frut.) che ha eseguito i test mediante schede di tipo quantitativo descrittivo con scale lineari, continue, parzialmente strutturate, ad intervalli da 0 a 10.
I risultati hanno evidenziato un elevato standard qualitativo per tutti gli ecotipi, mostrando alcune differenze nell’intensità dell’aroma. Quest’ultimo descrittore insieme alla dolcezza risultavano altamente correlati con la gradevolezza generale. L’analisi delle componenti principali (PCA) non discriminava in maniera netta i differenti profili sensoriali, supportando le argomentazioni sull’origine comune, già messe in luce con la caratterizzazione chimica.
Interessanti sono state, infine, le correlazioni tra i dati sensoriali e i dati strumentali. La gradevolezza generale era altamente correlata con i principali indici colorimetrici e chimici della maturazione e con la consistenza della polpa. L’elevata consistenza della polpa associata ad una “maturazione di consumo” del frutto, oltre a permettere una buona gestione del prodotto in fase post-raccolta, garantisce un elevato standard qualitativo sensoriale.
I dati ottenuti concorrono a definire un profilo completo dei frutti dimostrando un’omogeneità nell’identità sensoriale degli ecotipi ed evidenziando caratteri di distinzione rispetto alle più diffuse cultivar di pesco a polpa bianca. Il buon accordo tra la valutazione sensoriale e compositiva ha reso l’analisi sensoriale uno strumento fondamentale per la valutazione della qualità degli ecotipi di Pescabivona
Fruit composition and firmness of local apple and pear cultivars for traditional Italian preserves
No full textThe production of different traditional fruit-based preserves has been maintained in many areas of Italy until today. In Reggio Emilia province (North East of Italy) “savurett”, “savor” and mustards are obtained processing the fruits of old local varieties that combine a good adaptation to the environment and suitable qualitative characteristics. In the mountain areas the main cultivars used to make “savurett”, a preserve without added sugar, are pear Spalèr whose juice is cooked for a long time, and pear Nobile (Barabàn) of which slices are added at the end of thermal process to give consistency. Sometimes, apples of Rosa Romana, Ruggine and other varieties are also used. The apple cultivars Campanino and Ferro and the pear Nobile are used to produce mustard. The characterization of this raw material gives information on technological and sensory properties that contribute to the product quality. A survey and sampling was therefore carried out to study these different pear and apple varieties in comparison with current commercial cultivars for fresh consumption: Abate Fetel and Decana d’inverno pears and Golden Delicious, Granny Smith and Stayman apples. Pomological traits, fruit firmness, refractometric index, titratable acidity were analyzed. Low juiciness characterizes the apples Campanino and Ferro and the pear Nobile. Among apples, the highest soluble solids content was measured in apples Ruggine and Rosa Romana, which differed in acidity, with the highest values in Rosa Romana and the lowest in Ruggine. All the old apple varieties had a higher firmness than the commercial cultivars, with the highest values in Campanino and Ferro. The soluble solids content was similar in Spalér and Nobile but the acidity was the highest in Spalér and the lowest in Nobile. The low acidity and the high ratio between soluble solids content and acidity is likely the reason of the strong sweetness perceived in the consumption of Nobile fruits and derived products. This cultivar is characterized by the highest fruit firmness, which is outside the range of values generally found in commercial varieties for fresh consumption. The current exploitation of these products and varieties actively contributes to their safeguard and to the enhancement of the local economy
Aroma compounds in wines from Malvasia aromatica di Candia
No full textMalvasia aromatica di Candia (Vitis vinifera L.) is an Italian aromatic grapevine cultivated between Emilia Romagna and Lombardy regions. This grape has an aromatic intensity comparable to Muscat1, and it gives different type of wine: semi-sparkling, semi-dry or sweet wines and, more recently, dry or passito wines. In this study the evolution of aromatic compounds during the fermentation of semi-sparkling sweet and dry wine samples was studied. The extraction of free and glycosylated compounds was carried out by solid phase extraction onto C18-endcapped cartridges, while the detection was performed by gas chromatography coupled with mass spectrometry. Fermentative and varietal compounds were detected, observing similar profiles for both wines. The former compounds showed an increasing trend during the fermentation process, while the latter showed an opposite trend. In particular, the decrease of glycosylated terpenoids during the fermentation does not entail a corresponding increase of free fraction2. These compounds can be converted into other different, or absorbed onto yeast cell wall, or else stripped away due to gas development. Free and glycosylated varietal component was characterized by a prevalence of diol 1, diol 2, geraniol and its derivatives. These compounds make different the aroma profiles of Malvasia aromatica wines from Muscat white ones. In fact, the latter are characterized by a prevalence of linalool and its derivatives. Considerable free and bound contents of citronellol were also detected as well as linalool and its derivatives. In addition, the presence of other free compounds such as C13-norisoprenoids and benzenoids was observed. The main identified fermentative compounds were higher alcohols and their acetates as well as medium-chain fatty acids and their corresponding ethyl esters. Knowledge acquired through this study are useful in order to characterize the wines obtained from Malvasia aromatica di Candia and set up variety-oriented wine making protocols
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