•The aroma-profiles of fermented sour fish were characterized.•Eighteen aroma compounds (OAV>1) were confirmed.•Key aroma compounds were identified by recombination and omission experiments.•Key ...aroma compounds included four esters, two aldehydes and one furan.
In this study, key aroma compounds of low-salt fermented sour fish were characterized using headspace solid-phase micro extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC–MS), odor activity values (OAV) and aroma recombination and omission experiments. Eighty-eight volatile compounds, including esters, aldehydes, alcohols, acids, furans and pyrazines, were identified by HS-SPME-GC–MS. Eighteen aroma-active compounds were quantified by employing calculation of OAV greater than 1. A recombination aroma model prepared using aroma-active compounds based on the odorless fish matrix sensorially matched the aroma of fermented sour fish with a score of 4.5 out of 5. The omission experiment showed that 7 out of 18 compounds had a significant contribution to the overall aroma (P < 0.05). The key aroma compounds of fermented sour fish were concluded to be ethyl acetate (OAV = 189), ethyl hexanoate (OAV = 66), isoamyl acetate (OAV = 424), ethyl butyrate (OAV = 26), hexanal (OAV = 49), 1-hexadecanal (OAV = 14) and 2-pentylfuran (OAV = 13).
•The most predominant odorant in raw porcini (Boletus edulis) was 1-octen-3-one.•3-(Methylthio)propanal, 1-octen-3-one and pyrazines were key odorants in dry porcini.•Pyrazines were detected in raw ...porcini and increased sharply after drying.
A study was carried out to determine and compare the key aroma compounds in raw and dry porcini mushroom (Boletus edulis). The volatile fractions were prepared by solvent-assisted flavor evaporation (SAFE), and aroma extract dilution analysis (AEDA) combined with gas chromatography-mass spectrometry (GC–MS) was employed to identify the odorants. Selected aroma compounds were quantitated and odor activity values (OAVs) were calculated revealing OAVs ≥ 1 for 12 compounds in raw porcini, among which 1-octen-3-one showed the highest OAV. In addition to compounds with eight carbon atoms, 3-methylbutanal, (E,E)-2,4-decadienal and (E,E)-2,4-nonadienal were also responsible for the unique aroma profile. In dry mushroom OAVs ≥ 1 were obtained for 20 odorants. Among them, 3-(methylthio)propanal, 1-octen-3-one and pyrazines were determined as predominant odorants. Overall, drying increased complexity of volatile compounds, thus significantly changing the aroma profile of porcini, providing more desirable roasted and seasoning-like flavor and less grass-like and earthy notes.
Malz ist ein wichtiger Rohstoff in der Brauindustrie und von großer Bedeutung für die sensorischen Biereigenschaften. Mithilfe von intensiven thermischen Prozessen beim Mälzen werden Spezialmalze ...hergestellt, die üblicherweise dem gedarrten Basismalz zugesetzt werden, um Biere mit einzigartigen Farb‐ und Aromaeigenschaften herzustellen. Der Beitrag von Spezialmalzen wie Karamell‐ und Röstmalz zum Bieraroma und der Transfer von Geruchsstoffen vom Malz ins Bier wurden bisher jedoch nicht auf molekularer Ebene untersucht. Daher wurden sechs Biere, darunter drei untergärige Lagerbiere und drei obergärige Weizenbiere hergestellt, jeweils ein Referenzbier, ein Karamellmalzbier und ein Röstmalzbier. Die Referenzbiere wurden ausschließlich mit gedarrtem Basismalz hergestellt, bei den Spezialmalzbieren wurde hingegen ein Teil des gedarrten Gersten‐ oder Weizenbasismalzes durch Karamell oder Röstmalz der jeweiligen Getreideart ersetzt. Die untergärigen Biere wurden ausschließlich mit Gerstenmalz hergestellt, wohingegen die obergärigen Biere zu gleichen Teilen aus Gersten‐ und Weizenmalz gebraut wurden, wobei der Weizenmalzanteil die jeweiligen Spezialmalze beinhaltete. Das Aroma zeigte vor allem bananenartige, blumige, honigartige und fruchtige Noten in den Referenzbieren, karamellartige und malzige Noten in den Karamellmalzbieren sowie erdige und röstige Noten in den Röstmalzbieren. Insgesamt wiesen die untergärigen Spezialmalzbiere ein stärker karamellartiges, erdiges und röstiges Aroma auf, während die malzige Note zwischen den Biersorten vergleichbar war. Beide Referenzbiere wiesen eine insgesamt geringere Aromaintensität auf.
Die Geruchsstoffe wurden in den Bieren mittels Aromaextraktverdünnungsanalyse identifiziert, quantifiziert und anschließend wurden ihre Odor Activity Values (OAVs) berechnet. Insgesamt wiesen 30 Geruchsstoffe OAVs > 1 in mindestens einem der Biere auf. Eine Reihe bekannter Gärungsnebenprodukte zeigte ähnliche OAVs in den Bieren der jeweiligen Sorte. 19 der 30 Verbindungen wiesen jedoch erhebliche Unterschiede in den untergärigen Bieren auf sowie 15 innerhalb der obergärigen Biere. Die Biersorten unterschieden sich in den OAVs für Essigsäure, 2‐ Acetyl‐1‐pyrrolin und (f)‐ß‐Damascenon. 2‐Acetyl‐1‐pyrrolin war ein wichtiger Geruchsstoff in den untergärigen Bieren, insbesondere im Karamellmalzbier, nicht jedoch in den obergärigen Bieren. Insgesamt wiesen die Karamellmalzbiere hohe OAVs für fruchtige, karamellartige, röstige und erdig riechende Aldehyde, Furanone, Pyranone und Pyrazine auf, während die Röstmalzbiere hohe OAVs für phenolische, rauchige und süßlich riechende Phenole und einige erdig riechende Pyrazine aufwiesen. Um den Transfer der Geruchsstoffe vom Malz ins Bier zu bewerten, wurden diese in den Malzen quantifiziert und die Konzentrationen in den Bieren berechnet, die einem 100%igen Transfer entsprechen würden. Ein Vergleich mit den tatsächlichen Konzentrationen in den Bieren ergab, dass ein direkter Transfer nur eine geringe Rolle für die Menge der Geruchsstoffe in den Bieren spielte, was auf eine wesentliche Bildung aus Vorläufern und/oder eine Freisetzung von eingeschlossenen Geruchsstoffen während des Brauens hindeutete.
Die Dissertation von Herrn Féchir ist publikationsbasiert und beinhaltet zwei Paper:
Féchir M, Reglitz K, Mall V, Voigt J, Steinhaus M (2021) Molecular insights into the contribution of specialty barley malts to the aroma of bottom‐fermented lager beers. J Agric Food Chem 69:81908199. doi: 10.1021/acs.jafc.1c01846. Open Access.
Today's consumers demand natural and healthy functional food products with clean labels and less added ingredients and exogenous hydrocolloids. The goal is to produce dairy foods only made by using ...milk ingredients, while maintaining good sensory properties. Thanks to their multifunctional properties, dairy proteins are used to enhanced the texture of dairy products. However, their addition into dairy products can also have a great influence on taste and aroma perception.
This review concentrates on recent information regarding the impact of dairy proteins in dairy products with a focus on yogurts. The aim of the review is to highlight recent findings relating the composition and the physico-chemical properties of yogurts to their sensory properties.
The addition of dairy proteins in yogurts induces changes in their microstructure, which can explain the modifications of their texture properties. Modifying the protein content also tends to decrease the release of most flavor compounds, which can impact the overall aroma balance and change aroma perception. Modifications of texture and aroma perceptions can also be due to cognitive interactions. Dairy protein aggregates are particularly promising as dairy texture enhancers, however almost no sensory studies have been performed to investigate their impact on texture and aroma perception. More studies focusing on the impact of dairy protein aggregates on the organoleptic qualities of yogurts and dairy products are needed to obtain natural and low-fat products while maintaining a desirable texture quality.
•Milk proteins are efficient to modulate the texture of dairy products.•Milk protein-aroma binding can change aroma perception in dairy products.•Aroma perception is also influenced by the viscosity or hardness of dairy products.•Change of yogurt’s protein content impacts both texture and flavor perception.
•Tea aroma formed from glycosides, fatty acids, carotenoids, amino acids/sugars.•Aroma formation pathways: enzyme-mediated, Maillard and non-enzymatic reactions.•Aroma formation accelerated by tea ...endogenous enzymes.•Tea aroma concentration: black > white > oolong > dark > yellow > green.
Tea aroma is determined by the nature of the plant, the production processes, and many other factors influencing its formation and release. The objective of this study was to investigate the impact of manufacturing processes on the aroma composition of tea. Fresh tea leaves from the same cultivar and growing area were selected for producing the six types of tea: green, white, yellow, oolong, black, and dark teas. Comprehensive analysis by gas chromatography mass spectrometry (GC/MS) was performed for the volatiles of tea infusion, prepared by solid-phase microextraction (SPME), solid-phase extraction (SPE), and solvent assisted flavor evaporation (SAFE). A total of 168 volatile compounds were identified. Black tea has the highest volatile concentration of 710 µg/g, while green tea has the lowest concentration of 20 µg/g. Significantly affected by these processes, tea aroma molecules are formed mainly from four precursor groups: carotenoids, fatty acids, glycosides, and amino acids/sugars.
•Sensory analysis succeeded in identification of the overall aroma in liquors.•Ten sulfur compounds were identified and quantified for the first time.•PLSR showed that the correlation between ...compounds, sensory attributes and samples.
The aroma profiles of five Chinese light aroma-type liquors were investigated in this study. Gas chromatography-olfactometry (GC-O) and GC-flame photometric detection (FPD) were employed to investigate aroma-active compounds. A total of 80 odorants were identified, including ten sulfur compounds. In addition, aroma-active compounds (FD≥16) were determined, according to quantitative study and odor activity values (OAVs). Finally 27 key aroma compounds, mainly possessing fruity and floral notes, were successfully used to simulate the aromas of Chinese light aroma-type liquors by dissolving them in 53% (v/v) hydroalcoholic solution in their natural concentrations. Moreover, the correlation between the key aroma compounds, seven sensory attributes and liquor samples was evaluated through partial least-squares regression analysis.
Husks are the main source of bran and furfural flavor in traditional Chinese light‐aroma Baijiu, but they negatively affect its smell and taste. Here, bran husks were replaced with fresh bamboo to ...brew light‐aroma Baijiu. Flavor components in Jiupei and Baijiu were detected through headspace solid‐phase microextraction with gas chromatography–mass spectrometry, and physicochemical properties were assessed; flavor results were obtained from correlation, principal component, and cluster analyses. Starch and reducing sugar content in Jiupei negatively correlated with moisture, alcohol content, and acidity. Fresh bamboo reduced furfural from bran husks in Jiupei by 88.5% and increased alcohol distillation by 51%; it also improved starch efficiency (5%). Surprisingly, isovanillin was found to be present in Baijiu. Total Baijiu yield (57% ± 2.01%) was attained when crushed bamboo size was 1.5 cm × 0.3 cm × 0.3 cm. This study supports the use of fresh bamboo (an eco‐friendly alternative for husks) in brewing light‐aroma Baijiu.
Practical Application
The use of fresh bamboo as a replacement for rice husks in brewing light‐aroma Baijiu was investigated. It attenuated the chaff taste in light‐aroma Baijiu and increased the liquor yield. Surprisingly, isovanillin was also present in the base Baijiu, and it added to the fragrance. This study not only supports the use of bamboo as an auxiliary material for brewing light‐aroma Baijiu but also provides a reference for brewing light‐aroma Baijiu with alternative auxiliary materials.
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