1,721,167 research outputs found
Flavor Chemistry and Technology: The Challenges of Working with Flavors in the Food Industry
Full text linkThe term “flavor” refers to the overall sensory experience of a food or beverage, including olfaction (the perception of smell and aroma), gustation (the perception of taste), and trigeminal sensations, which combine the perception of texture, mouthfeel, temperature, and chemesthesis (i [...
L’AROMA DELL’OLIO
No full textLa percezione della qualità sensoriale dell’olio extra vergine di oliva (OEVO) investe complessi fenomeni neurofisiologici alla base delle sensazioni olfatto-gustative che determinano il flavour dell’olio. Tutto ciò, nella valutazione pratica della qualità sensoriale di un olio, può generare da una parte problemi di riproducibilità del giudizio dei panel di assaggiatori, dall’altra difficoltà nel fornire informazioni ai consumatori per scegliere ‘col naso’ un OEVO di elevata qualità. Se potrebbe essere relativamente semplice comunicare al consumatore l’importanza del driver ‘amaro-piccane’ per scegliere oli di elevata qualità nutrizionale, molto più complesso è ‘educare’ l’olfatto al riconoscimento delle note positive e negative dell’olio vergine di oliva senza tener conto della esperienza o ‘memoria olfattiva’ di ciascun soggetto. Gli stimoli che ogni molecola trasmette ai nostri organi di senso, infatti, non sono elaborati indipendentemente l’uno dall’altro, ma forniscono al nostro cervello un’immagine complessiva. Tra la miriade di stimolazioni fornite dagli oltre 180 composti volatili e fenolici dell’OEVO vi possono essere, poi, effetti antagonistici, sinergici e di modificazione della qualità dello stimolo.
Ben diverse sono anche le sensazioni olfattive ‘ortonasali’ e ‘retronasali’ indotte dello stesso OEVO, a causa non solo delle soglie di percezione delle singole molecole ma anche dalle interazioni dei fenoli e delle sostanze volatili con la saliva umana.
Numerosi studi sono stati prodotti negli ultimi anni sull’effetto di variabili agronomiche e tecnologiche sulle sostanze fenoliche e volatili dell’OEVO. Poco studiata, invece, è stata la relazione tra composti fenolici, volatili e risposta sensoriale.
Decodificare la complessa interazione tra molecole fenoliche e volatili, definire il ruolo di ciascuna di esse sulla percezione della qualità dell’olio, rappresentano ancora obiettivi molto importanti, sia per l’accurata classificazione merceologica dell’olio vergine che per la definizione oggettiva della sua tipicità/identità sensoriale.
In questa lecture verranno presentate alcune recenti acquisizioni su: i) relazione tra molecole volatili e note sensoriali tipiche degli OEVO italiani, con particolare riferimento alle modalità di misura quantitativa dei composti volatili (SPME-GC/MS) e di espressione del loro impatto odoroso (serie aromatiche), ii) interazioni aromi-saliva, saliva-fenoli e saliva-fenoli-aromi studiate in vivo mediante APCI-MS; iii) effetto delle molecole fenoliche e della saliva sul rilascio di aroma dell’OEVO, anche in relazione alla variabilità individuale ed a diverse condizioni fisiologiche, iv) effetti antagonistici e sinergici tra molecole volatili nella percezione dei pregi e difetti dell’olio (aromi ‘verdi’ e difetti fermentativi, v) qualità nutrizionale dell’OEVO ed effetto saziante di alcune molecole aromatiche contenute nell’olio extra vergine di oliva
La ruota alata. I primi 40 anni della Polizia Ferroviaria in Italia
Full text linkNella primavera del 1915, con l'entrata dell'Italia nel conflitto mondiale, i progetti di riforma sul servizio e sull'organizzazione della Polizia Ferroviaria ebbe un brusco rallentamento, in quanto l'autorità governativa si occupò prevalentemente di dettare nuove disposizioni sul controllo alle frontiere e sulla pianificazione del ruolo delle forze armate e di polizia per la vigilanza e laprotezione del servizio ferroviario.
La fine del 1918, trovò i Commissariati Compartimentali di Pubblica Sicurezza impreparati per affrontare le condizioni disastrose di sicurezza in cui la Guerra aveva lasciato gli scali ferroviari. L'assunzione in blocco di personale ferroviario, senza nessuna garanzia e controllo sui precedenti penali e politici, e la propaganda sovversiva che si faceva strada preoccupò il Governo ed espose i Commissariati Compartimentali alle più dure fatiche per arginare il dilagare dei furti ed arrestare la marea bolscevica che ogni girno diventava sempre più pericolosa
Temporal changes of virgin olive oil volatile compounds in a model system simulating domestic consumption: The role of biophenols
No full textVirgin olive oil (VOO) aroma is one of the main quality attributes, to be maintained and preserved from the production
to the use. We investigated the changes in VOO volatile compounds in amodel system,made by refined
olive oil spiked with selected VOO volatile molecules representative of its aroma, and the effect of VOO phenolic
compounds addition upon storage to simulate the home consumption. Storage up to 7 dayswas carried out under
conditions simulating the home-use/storage of the oil, at 10 °C in darkness, by sampling periodically an aliquot of
oil by opening the bottle. SPME–GC/MS was used to quantify headspace concentration of 12 target volatile compounds.
Storage resulted in a general lowering of most of the key aroma compounds. The presence of phenolic
compounds resulted in a lower loss (17–44%) of aroma compounds with respect to the systemwithout phenolics,
whereas the strength of the effect depended upon the chemical classes and specific volatile compounds considered.
Our results showed how the volatiles changes in 1 week of use and that biophenols reduce the loss of
positive odor notes of VOO also during home/restaurant consumption and storage once the bottle is opened
Orthonasal vs. retronasal: Studying how volatiles' hydrophobicity and matrix composition modulate the release of wine odorants in simulated conditions
No full textIn this study a Retronasal Aroma Simulator was employed to compare the release of volatiles from two different white wine matrices (TW: table, SW: sweet) with and without the addition of human or artificial saliva to simulate retronasal and orthonasal conditions, respectively. The headspace volatiles were isolated by Solid Phase Microextraction under dynamic conditions and identified and quantified by Gas-Chromatographic analyses. Compared to the orthonasal, the retronasal conditions modified the release of odorants from both wines and the observed trends cannot be ascribed only to dilution consequent to saliva addition. The relative amounts of volatiles belonging to different chemical classes were modified in the presence of saliva with possible sensory implications concerning some fruity (esters), oxidative (furans) and varietal (linalool, vitispirane) odorants. Regression analyses show that the impact of saliva depends on the volatile (concentration and hydrophobicity) and the non-volatile (residual sugars) composition of the wine. The highly significant linear models (TW: R2 = 0.988; SW: R2 = 0.993) indicate that the release of volatiles is logP octanol/water dependent in both the wines but the slopes change with matrix composition. This suggest that in the presence of human saliva the release of odorants with similar hydrophobicity vary as a linear function of their initial headspace concentration above the wine and is modulated by the composition of the wine matrix. Differences between artificial and human saliva confirmed that the retronasal release of wine odorants is affected by the whole salivary composition and suggest that salivary components different from mucin and α-amylase are involved in the retention of the most hydrophobic volatiles as well as in the metabolization of some aromas
Hydrolysis of Wine Aroma Precursors during Malolactic Fermentation with Four Commercial Starter Cultures ofOenococcus oeni
No full textThe ability of four commercial preparations of Oenococcus oeni lactic acid bacteria (EQ 54, Lalvin OSU, Uvaferm Alpha, and Lalvin 31) to hydrolyze wine aroma precursors was evaluated by measuring the concentration of free and bound aroma compounds at the end of malolactic fermentation carried out in model wines containing a mixture of glycosides extracted from Muscat wine. At pH 3.4 there
was a decrease in glycosylated compounds matched by a concomitant increase in free forms in all starter cultures tested. When malolactic fermentation was carried out at pH 3.2, a significant decrease in the ability to hydrolyze aroma precursors was observed for two of the cultures tested (Uvaferm Alpha and Lalvin 31). Large differences in the extent of hydrolysis and in the specificity of this activity
toward specific aroma precursors were observed and appeared to be related to the chemical structure
of the aglycon as well as to individual characteristics of each starter culture. The amounts of glycosylated aroma compounds released during malolactic fermentation suggest that O. oeni can alter the sensory characteristics of wine through the hydrolysis of aroma precursors
Whipped chickpea aquafaba as a fat replacer in ice cream: Effect on sensory and physicochemical properties
Full text link: Whipped chickpea aquafaba (WAF) exhibits foaming, emulsifying, and gelling properties, making it a potential ingredient for replacing cream in ice cream formulations. The aim of this study was to use WAF in combination with whey protein isolate (WPI) to produce low-fat coffee ice cream with 50% (L50) and 80% (L80) milk cream replacement. The melting rate, color, texture, volatile compounds, and sensory attributes were analyzed to explore the physical, chemical, and sensory properties of the low-fat ice creams compared to their full-fat counterparts. Fat substitute performance varied based on cream replacement levels, with L50 1:0 (WAF:WPI) and L80 1:0 achieving 25% and 40% reductions in calorie content, respectively. The foaming properties of aquafaba resulted in an increased overrun, particularly in formulations where the cream reduction was 50%. While the 80% replacement showed higher intensity of "hardness," "brown color," and "melting" sensory descriptors, the 50% cream-replaced ice cream showed only slight differences compared to the full-fat version, like a higher perception of ice crystals. The combination of WAF and WPI in ice cream provides sensory properties and releases pyrazines, responsible for the coffee aroma, similar to full-fat ice cream. The 1:1 WAF:WPI mixture for 50% cream reduction provided a suitable cream replacement, as this formulation resulted in ice cream that was not identified as different from the full-fat control ice cream in the triangle test. PRACTICAL APPLICATION: This study demonstrates that whipped aquafaba, a by-product of chickpea processing, can be effectively used to reduce the fat content in ice cream without compromising sensory quality. In addition to promoting the development of healthier low-fat ice creams, this approach also contributes to food industry sustainability by reusing a commonly discarded by-product
Analisi di componenti odorosi mediante tecniche poli-strumentali
No full textA study on the aroma of Ruchè wine was conduced by GC-FID, GCMS and GC-olfactometry analysis.
Ninety two volatile compounds were identified in the organic
extract obtained by a liquid-liquid extraction with Freon 113. Aroma of Ruchè wine resulted characterized by a high concentration of terpenes compounds, among them linalool,
geraniol and ethyl geraniate were responsible for the floral and fruity notes, typical of this wine. β-damascenone could contribute to aroma of Ruchè wine with a tea odour. Other odorous compounds were yeast by-products such as
esters and acetates responsible of fruity notes. Acetophenone,
γ-nonalactone and furaneol resulted responsible for almond, coconut, strawberries jam odours as well as volatile phenols guaiacol and ethylguaiacol for smoke odours
Odorants characterization of dehydrated grapes and corresponding wines, and management of vinification and stabilization to preserve aroma
No full textIn this work, after illustrating experimental results about the evolution of free and bound aroma compounds during sound grapes dehydration in different conditions, and about the odorants characteristics of some wines obtained by this kind of grapes, we will discuss about the winemaking practices encouraging the release and the preservation of these aromas from dehydrated grapes to wine, as suitable means for the making of products characterized by complex and specific aroma
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