Key Aroma Compounds of Dark Chocolates Differing in Organoleptic Properties: A GC-O Comparative Study

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates’ headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi² test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product.

Download Full-text

Characterization of the Key Aroma Compounds in Traditional Hunan Smoke-Cured Pork Leg (Larou, THSL) by Aroma Extract Dilution Analysis (AEDA), Odor Activity Value (OAV), and Sensory Evaluation Experiments

Foods ◽

10.3390/foods9040413 ◽

2020 ◽

Vol 9 (4) ◽

pp. 413

Author(s):

Dandan Pu ◽

Yuyu Zhang ◽

Huiying Zhang ◽

Baoguo Sun ◽

Fazheng Ren ◽

...

Keyword(s):

Active Regions ◽

Aroma Compounds ◽

Aroma Extract Dilution Analysis ◽

Sensory Qualities ◽

Key Odorants ◽

Potent Odorants ◽

Odor Activity Value ◽

First Time ◽

Ranking Analysis

The key aroma compounds in smoke-cured pork leg were characterized by gas chromatography–olfactometry coupled with aroma extract dilution analysis (GC–O/AEDA), odor activity value (OAV), recombination modeling, and omission tests. Ranking analysis showed that pork leg smoke-cured for 18 days had the best sensory qualities, with strong meaty, smoky, roasty, woody, and greasy attributes. Thirty-nine aroma-active regions with flavor dilution (FD) factors ranging from 9 to 6561 were detected. Overall, 3-ethylphenol had the highest FD factor of 6561, followed by 2,6-dimethoxyphenol, 3,4-dimethylphenol, 4-ethylguaiacol, 4-methylguaiacol, 3-methylphenol, and 2-acetyl-1-pyrroline, with FD ≥243. Among 39 aroma compounds, 27 compounds with OAVs ≥1 and were potent odorants. A similarity of 90.73% between the recombination model and traditional Hunan Smoke-cured Pork Leg (THSL) sample was obtained. Omission tests further confirmed that (E)-2-nonenal, 2-methoxy-4-vinylphenol, guaiacol, 3-ethylphenol, 2,6-dimethylphenol, 2-acetyl-1-pyrroline, and methional were key odorants in smoke-cured pork leg. Additionally, 2-acetyl-1-pyrroline (38.88 μg/kg), which contributes to a roasty aroma, was characterized here as a key odorant of smoke-cured pork leg for the first time.

Download Full-text

Survival of Gastric and Enterohepatic Helicobacter spp. in Water: Implications for Transmission

Applied and Environmental Microbiology ◽

10.1128/aem.02241-07 ◽

2008 ◽

Vol 74 (6) ◽

pp. 1805-1811 ◽

Cited By ~ 43

Author(s):

N. F. Azevedo ◽

C. Almeida ◽

I. Fernandes ◽

L. Cerqueira ◽

S. Dias ◽

...

Keyword(s):

Membrane Integrity ◽

Hierarchical Cluster ◽

Culture Method ◽

Oral Route ◽

Human Stomach ◽

Aquatic Environments ◽

Integrity Assessment ◽

Environmental Reservoir ◽

H Pylori ◽

First Time

ABSTRACT Part of the reason for rejecting aquatic environments as possible vectors for the transmission of Helicobacter pylori has been the preference of this microorganism to inhabit the human stomach and hence use a direct oral-oral route for transmission. On the other hand, most enteric bacterial pathogens are well known for being able to use water as an environmental reservoir. In this work, we have exposed 13 strains of seven different Helicobacter spp. (both gastric and enterohepatic) to water and tracked their survival by standard plating methods and membrane integrity assessment. The influence of different plating media and temperatures and the presence of light on recovery was also assessed. There was good correlation between cultivability and membrane integrity results (Pearson's correlation coefficient = 0.916), confirming that the culture method could reliably estimate differences in survival among different Helicobacter spp. The species that survived the longest in water was H. pylori (>96 h in the dark at 25°C), whereas H. felis appeared to be the most sensitive to water (<6 h). A hierarchical cluster analysis demonstrated that there was no relationship between the enterohepatic nature of Helicobacter spp. and an increased time of survival in water. This work assesses for the first time the survival of multiple Helicobacter spp., such has H. mustelae, H. muridarum, H. felis, H. canadensis, H. pullorum, and H. canis, in water under several conditions and concludes that the roles of water in transmission between hosts are likely to be similar for all these species, whether enterohepatic or not.

Download Full-text

Genome Sequence of the Wine Yeast Saccharomycodes ludwigii UTAD17

Microbiology Resource Announcements ◽

10.1128/mra.01195-18 ◽

2018 ◽

Vol 7 (18) ◽

Cited By ~ 4

Author(s):

Maria J. Tavares ◽

Ulrich Güldener ◽

Marcos Esteves ◽

Arlete Mendes-Faia ◽

Ana Mendes-Ferreira ◽

...

Keyword(s):

Genome Sequence ◽

Wine Yeast ◽

Aroma Compounds ◽

Content Type ◽

Fermented Beverages ◽

Spoilage Yeast ◽

Wine Spoilage ◽

Saccharomycodes Ludwigii ◽

First Time

This work describes, for the first time, the genome sequence of a Saccharomycodes ludwigii strain. Although usually seen as a wine spoilage yeast, S. ludwigii has been of interest for the production of fermented beverages because it harbors several interesting properties, including the production of beneficial aroma compounds.

Download Full-text

Effects of cocoa products/dark chocolate on serum lipids: a meta-analysis

European Journal of Clinical Nutrition ◽

10.1038/ejcn.2011.64 ◽

2011 ◽

Vol 65 (8) ◽

pp. 879-886 ◽

Cited By ~ 116

Author(s):

O A Tokede ◽

J M Gaziano ◽

L Djoussé

Keyword(s):

Serum Lipids ◽

Meta Analysis ◽

Dark Chocolate ◽

Cocoa Products

Download Full-text

Functional Properties of Grasping-Related Neurons in the Ventral Premotor Area F5 of the Macaque Monkey

Journal of Neurophysiology ◽

10.1152/jn.00463.2005 ◽

2006 ◽

Vol 95 (2) ◽

pp. 709-729 ◽

Cited By ~ 196

Author(s):

Vassilis Raos ◽

Maria-Alessandra Umiltá ◽

Akira Murata ◽

Leonardo Fogassi ◽

Vittorio Gallese

Keyword(s):

Functional Properties ◽

Three Dimensional ◽

Hierarchical Cluster ◽

Visual Presentation ◽

Macaque Monkey ◽

Premotor Area ◽

Three Dimensional Objects ◽

Optimal Activity ◽

Visual Properties ◽

First Time

We investigated the motor and visual properties of F5 grasping neurons, using a controlled paradigm that allows the study of the neuronal discharge during both observation and grasping of many different three-dimensional objects with and without visual guidance. All neurons displayed a preference for grasping of an object or a set of objects. The same preference was maintained when grasping was performed in the dark without visual feedback. In addition to the motor-related discharge, about half of the neurons also responded to the presentation of an object or a set of objects, even when a grasping movement was not required. Often the object evoking the strongest activity during grasping also evoked optimal activity during its visual presentation. Hierarchical cluster analysis indicated that the selectivity of both the motor and the visual discharge of the F5 neurons is determined not by the object shape but by the grip posture used to grasp the object. Because the same paradigm has been used to study the properties of hand-grasping neurons in the dorsal premotor area F2, and in the anterior intraparietal area (AIP), a comparison of the functional properties of grasping-related neurons in the three cortical areas (F5, F2, AIP) is addressed for the first time.

Download Full-text

Identification of Floral Fragrances and Analysis of Fragrance Patterns in Herbaceous Peony Cultivars

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04420-18 ◽

2018 ◽

Vol 143 (4) ◽

pp. 248-258 ◽

Cited By ~ 1

Author(s):

Chaowei Song ◽

Qi Wang ◽

Jaime A. Teixeira da Silva ◽

Xiaonan Yu

Keyword(s):

Sensory Evaluation ◽

Aromatic Compounds ◽

Hierarchical Cluster ◽

Gas Chromatography Mass Spectrometry ◽

Volatile Components ◽

Herbaceous Peony ◽

Phenylethyl Alcohol ◽

Evaluation Scores ◽

Flower Fragrance ◽

First Time

Thirty herbaceous peony (section Paeonia of the genus Paeonia) cultivars were divided into four groups (no fragrance, light fragrance, medium fragrance, or intense fragrance) based on their sensory evaluation scores. Using dynamic headspace sampling (DHS) and automatic thermal desorption–gas chromatography/mass spectrometry (ATD-GC/MS), 130 volatile organic components were detected in these 30 cultivars and a total of 72 compounds were identified as scent components. The main compounds were phenylethyl alcohol, β-caryophyllene, linalool, (R)-citronellol, and nerol. Selecting α-pinene as the standard, the volatile components of these cultivars were quantitatively analyzed. By combining the sensory evaluation scores and the results of quantitative analysis, we found that ‘Going Bananas’, ‘Cream Delight’, ‘Zhu Sha Pan’, ‘Qiao Ling’, ‘Duchess de Nemours’, and ‘Yang Fei Chu Yu’ displayed an intense fragrance and, thus, had relatively high commercial value for the flower fragrance industry. ‘Red Magic’, ‘Joker’, ‘Fairy Princess’, ‘Lovely Rose’, ‘Carina’, and ‘Etched Salmon’ were excluded from the hierarchical cluster of aromatic compounds and the analysis of fragrance patterns because of the low amount of fragrance they released and poor sensory evaluation results. Based on a cluster analysis, assessment of the major aromatic compounds, and the results of sensory evaluation, the remaining 24 cultivars were divided into five fragrance patterns for the first time: woody scent [cluster I (major fragrance β-caryophyllene)], fruity scent [cluster II (phenylethyl alcohol)], lily scent [cluster III (linalool)], rose scent {cluster IV [(R)-citronellol]}, and an orange blossom scent [cluster V (nerol)].

Download Full-text

Characterization of Key Odorants in Scallion Pancake and Investigation on Their Changes during Storage

Molecules ◽

10.3390/molecules26247647 ◽

2021 ◽

Vol 26 (24) ◽

pp. 7647

Author(s):

Binshan Liu ◽

Shiqi Xu ◽

Zhizhong Dong ◽

Yuping Liu ◽

Xiaoming Wei ◽

...

Keyword(s):

Aroma Extract Dilution Analysis ◽

Flavor Compound ◽

Aroma Profile ◽

Extraction Solvent ◽

Dipropyl Disulfide ◽

Gas Chromatography Olfactometry ◽

Key Odorants ◽

First Time ◽

Methyl Propyl Disulfide

To characterize key odorants in scallion pancake (SP), volatiles were extracted by solvent extraction-solvent assisted flavor evaporation. A total of 51 odor-active compounds were identified by gas chromatography-olfactometry (GC-O) and chromatography–mass spectrometry (GC-MS). (Z/E)-3,6-Diethyl-1,2,4,5-tetrathiane was detected for the first time in scallion food. Application of aroma extract dilution analysis to extracts showed maltol, methyl propyl disulfide, dipropyl disulfide and 2-pentylfuran had the highest flavor dilution (FD) factor of 4096. Twenty-three odorants with FD factors ≥ 8 were quantitated, and their odor active values (OAVs) were calculated. Ten compounds with OAVs ≥ 1 were determined as the key odorants; a recombinate model prepared from the key odorants, including (E,E)-2,4-decadienal, dimethyl trisulfide, methyl propyl disulfide, hexanal, dipropyl trisulfide, maltol, acetoin, 2-methylnaphthalene, 2-pentylfuran and 2(5H)-furanone, successfully simulated the overall aroma profile of SP. The changes in odorants during storage were investigated further. With increasing concentrations and OAVs during storage, hexanal became an off-flavor compound.

Download Full-text

Aroma potential of three autochthonous grapevine varieties from Tunisia

OENO One ◽

10.20870/oeno-one.2008.42.4.813 ◽

2008 ◽

Vol 42 (4) ◽

pp. 231 ◽

Cited By ~ 1

Author(s):

Imène Souid ◽

Zemni Hassene ◽

Eva Sánchez Palomo ◽

Maria Soledad Pérez-Coello ◽

Abdelwahed Ghorbel

Keyword(s):

Grape Juice ◽

Free Fraction ◽

Aroma Compounds ◽

Vitis Vinifera L ◽

Qualitative And Quantitative ◽

Linalool Oxide ◽

Grape Juices ◽

Grape Varieties ◽

First Time ◽

C6 Compounds

Aims: The aim of the present work is to characterize the aromatic profiles of three Tunisian autochthonous grapevine (Vitis vinifera L.) varieties (Asli, Beldi and Ferrani).Methods and results: The GC-MS analysis of the autochthonous grapevine varieties studied allowed identifying 38 volatile compounds in the free fraction and 36 glycosidically bound aroma compounds. Volatile C6 compounds were typical for the studied varieties especially for Asli variety. The analysis of the liberated aglycones through enzymatic hydrolysis show that a-terpineol and cis linalool oxide pyran that did not appear as free aroma compounds were found with significantly highest concentration in Asli grape juice. Also, 3-oxo-a-ionol and 3-hydroxy-7,8-dihydro-b-ionol were found only under their glycosidically bound forms with significantly higher concentrations in Asli and Ferrani than in Beldi grape juices.Conclusion: The results obtained in the present work show qualitative and quantitative differences in the aroma profiles among the studied varieties. However, non-terpenyl compounds were the most abundant aroma substances in the three studied varieties.Significance and impact of the study: The present work characterize, for the first time, the aromatic profiles of three Tunisian autochthonous grapevine varieties (Asli, Beldi and Ferrani) and constitutes a major contribution to the aroma chemistry of these three grape varieties.

Download Full-text

Effects of Cocoa Polyphenols and Dark Chocolate on Obese Adults: A Scoping Review

Nutrients ◽

10.3390/nu12123695 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3695

Author(s):

Hasmiza Halib ◽

Amin Ismail ◽

Barakatun-Nisak Mohd Yusof ◽

Naomi Osakabe ◽

Zulfitri Azuan Mat Daud

Keyword(s):

Scoping Review ◽

Weight Control ◽

Metabolic Diseases ◽

Public Health Problem ◽

Dark Chocolate ◽

Major Public Health Problem ◽

Obese Adults ◽

Cocoa Products ◽

Different Populations

Obesity remains a major public health problem due to its increasing prevalence. Natural products have become common as adjunct therapeutic agents for treating obesity and preventing metabolic diseases. Cocoa and its products are commonly consumed worldwide. Dark chocolate, a rich source of polyphenols, has received attention lately for its beneficial role in the management of obesity; however, conflicting results are still being reported. This scoping review aims to provide a comprehensive understanding of the existing literature on the relationship and effects of cocoa and dark chocolate intake among obese adults. We searched multiple databases for research investigating the consumption of cocoa and/or dark chocolate in managing obesity among adults. This review includes epidemiological and human studies that were published in English over the last 10 years. Our review of the current literature indicates that epidemiological and human trials with obese adults have shown inconsistent results, which may be due to the different populations of subjects, and different types of cocoa products and doses used for intervention. Studies among obese adults are mainly focusing on obese individuals with comorbidities, as such more studies are needed to elucidate the role of cocoa polyphenols in weight control and preventing the risk of chronic diseases among obese individuals without comorbidities as well as healthy individuals. Careful adjustment of confounding factors would be required. The effects of cocoa and dark chocolate intake on obese adults were discussed, and further research is warranted to identify the gaps.

Download Full-text

Expression of Stem Cell Markers in Primo Vessel of Rat

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/438079 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

Eun Seok Park ◽

Jeong Hoon Lee ◽

Won Jin Kim ◽

Jinbeom Heo ◽

Dong Myung Shin ◽

...

Keyword(s):

Stem Cell ◽

Pcr Analysis ◽

Acupuncture Points ◽

Stem Cell Markers ◽

Molecular Features ◽

Detection Frequency ◽

Liver Surface ◽

First Time

Accumulating line of evidence support that adult tissues contain a rare population of pluripotent stem cells (PSCs), which differentiate into all types of cells in our body. Bonghan microcell (primo microcells (PMCs)) discovered in 1960s was reported to have a pluripotency like a stem cellin vivoas well asin vitrocondition. Here, we describe the detailed morphology and molecular features of PMCs. PMCs reside in Bonghan duct (primo vessel (PV)) reported as a corresponding structure of acupuncture points and meridian system. We found that PMCs were frequently observed in the liver surface of the rat between 300 g and 400 g from April to June, suggesting that the their detection frequency depends on the weight, the season, and the organ of rat. As reported, PMCs freshly isolated from PVs were spherical ~1-2 μm microsized cells. In contrast, a unique bithread or budding-shaped PMCs emerged during tissue culture around 8 days. RT-PCR analysis demonstrated that PVs-derived cells express theOct4, the most important PSCs gene, in addition to several PSCs markers (Sox2,Stella,Rex1, andKlf4). Thus, we for the first time provide the evidence about Oct4-expressing stem-like characteristics for cells resident in PVs, a possible novel stem cell enriched niche.

Download Full-text