Interest in plant‐based meat alternatives (PMBAs) has been rapidly growing in both the food research community and the food industry due to higher consumer demands in recent years. However, ...scientific data regarding the health and aroma aspects of PBMA are rare. In this study, the fatty acids (FAs) and volatile flavor compounds (VFCs) were profiled in four types of plant‐based burgers (PBs) and compared to beef burger (BB). Over 40 FAs and 64 VFCs were detected and quantified in the samples. Nonsignificant differences (α = 0.05) were observed in the percentages of most FAs between uncooked and cooked PBs. PBs contained lower percentages of saturated FAs and trans‐FAs, higher percentages of unsaturated FAs, and lower ratio of n‐6 to n‐3 FAs comparing to the BB. The FA profiles in PBs are mainly determined by their ingredients. The VFC profile of cooked PBs was different from that of the uncooked ones. The ingredients, thermally induced Maillard reaction, and lipid oxidation had contributed to the formation of the flavor. For uncooked samples, the VFC profiles of PB 3 and PB 4 were similar to that of BB. While for cooked samples, PB 1 had similar VFC profile as BB. This illustrated the importance of the cooking process for aroma formation; however, ingredients, such as spices, remain an important source of VFCs in these burger samples. Ingredient optimization could be an effective strategy to enhance the flavor of PBs to resemble BB.
Practical Application
This study provides the knowledge of health and aroma‐related components in both raw and cooked PBs, including FA and VFC profiles. It also explains the source of those components. This will not only help consumer's decision making in choosing plant‐based meat alternatives, but also help the related industry to choose proper ingredients to optimize the final products.
General emissions of volatile organic compounds from wood are well investigated, but only limited information is available on the odor-active substances contained therein. To close this gap, we aimed ...at specifically elucidating the odorous constituents of wood from incense cedar
Calocedrus decurrens
(Torr.) Florin; this material is commonly used for the production of a range of products such as pencils and interior accessories. Targeted odorant analysis requires specialized techniques combining modern odorant analytical tools with human-sensory evaluation. Following this concept, the odor profile of the wood sample was first evaluated by human-sensory analyses. Then, the most potent wood odorants were characterized by means of gas chromatography–olfactometry and ranked according to their odor potency via aroma extract dilution analysis. With use of this approach, more than 60 odorous substances were detected, and the 22 most potent odorants were successfully identified by gas chromatography–mass spectrometry/olfactometry and two-dimensional gas chromatography–mass spectrometry/olfactometry. Among the main odorants found were a series of terpenes, several degradation products of fatty acids, and a number of odorants with a phenolic core moiety. Five odorants are reported here for the first time as wood odorants, such as γ-octalactone and 3-phenylpropanoic acid; thymoquinone was demonstrated for the first time to have a pencil-like odor quality.
A quantitative 1H NMR-based approach was established, which allowed the direct and noninvasive analysis of molecular interactions between key coffee odorants and high-molecular-weight (HMW) ...melanoidin polymers. A clear distinction between covalent and noncovalent interactions was achieved by monitoring the time dependency of odorant–polymer interactions, resulting in four scenarios: covalent, π–π, covalent and π–π–, as well as no interactions. Evaluation of temperature influence on e.g. 2-furfurylthiol (FFT), revealed an altered behavior with increased π–π stacking at lower temperatures and accelerated covalent interactions at higher temperatures. Human sensory experiments with HMW material and a coffee aroma reconstitution model showed a drastic reduction of “roasty/sulfury” aroma notes, as well as an increased “sweetish/caramel-like” flavor. The lack of interactions between the “sweetish/caramel” smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone with the HMW melanoidins in combination with the high binding affinity of coffee thiols explains the sensory evaluation and is obviously the reason for the fast disappearance of the typical “roasty/sulfury” aroma impressions of a freshly prepared coffee brew.
Background and Aims
Wines aged in wood barrels are likely to contain Brettanomyces yeasts, which are able to produce off‐flavour compounds such as ethylphenols and vinylphenols. In this work, both ...off‐flavoured and pleasant phenol compounds were quantified in Portuguese wines with an improved analytical technology.
Methods and Results
A novel one‐step dispersive liquid–liquid microextraction method with simultaneous derivatisation followed by fast low‐pressure GC/MS was optimised and applied to 49 red wine samples of commercial and private origin. The analytical performance demonstrated the ability of the proposed method to accurately measure all the analytes under study.
Conclusions
Ethyl and vinylphenols were present in most of the wines, at a concentration frequently higher than their preference threshold, and thus high enough to affect the overall aroma of the wine. Home‐made wines had a higher concentration of off‐flavour compounds in contrast with that of commercial wines, which had a high concentration of pleasant flavour compounds. Statistical analysis showed that less expensive wines exhibited a significantly lower concentration of syringol, and there was a tendency for the concentration of vinylphenols and ethylphenols to increase throughout wine aging.
Significance of the Study
The presence of off‐flavour phenols is a major concern of the wine industry, requiring great attention during the different stages of the winemaking process, so that wine aroma is not negatively affected.
•Constructing flavor wheel to expound flavor evolution during Pu-erh tea fermentation.•β-damascenone was firstly found contributing most to the aroma of Pu-erh tea.•Revealing the aroma-active ...compounds forming the three characteristic aroma types.•Revealing markers responsible for aroma differences in different fermented stages.•Summarizing the metabolic evolutions of key flavor-active compounds systematically.
For the urgent need for fermentation control and product quality improvement of Pu-erh tea, gas chromatography-mass spectrometry and odor activity value (OAV) were used to comprehensively investigate the flavor-active compounds during artificial fermentation of Pu-erh tea. A flavor wheel was constructed to expound the sensory attributes evolution during fermentation. With an increased total volatiles content, 43 were significantly up-regulated and 30 were down-regulated among 131 detected volatiles. Key active compounds of three aroma types, namely fresh fragrance, fruit-fungus fragrance and stale-Qu fragrance, were analyzed based on OAV. β-damascenone was firstly found contributing most to the aroma of Pu-erh tea, followed by 1,2,3-methoxybenzene and (E,E)-2,4-nonadienal. γ-terpinene, linalool, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 4-ethylveratrol were identified as the potential markers responsible for aroma differences among three fermentation stages. Finally the metabolic evolution of key flavor-active compounds were systematically summarized. This study provides significant guidance in fermentation control and new product development of Pu-erh tea.
•Total of 274 volatile compounds were identified in CB and HB tomato pastes.•The aroma compounds extracted by SAFE in CB tomato paste were more abundant than HB.•10 aroma-active compounds were ...detected for the first time in tomato pastes.•9 volatiles were identified for the first time in tomato pastes.•More compounds were identified using GC × GC-O-TOF-MS compared with GC-O-MS.
GC × GC-O-TOF-MS and GC-IMS have attracted increasing attention in complex food flavor analysis due to their high resolution and sensitivity. However, very few studies have attempted to identify the aroma components of tomato pastes through these techniques. Herein, the present study comprehensively characterized the aroma profiles of cold and hot break tomato pastes using SAFE-GC-O-MS, SAFE-GC × GC-O-TOF-MS, and HS-GC-IMS for the first time. A total of 274 volatile compounds were identified, far more than previously reported. About 87 % of these compounds can be identified by GC × GC-O-TOF-MS, exceeding 6 times that of GC-O-MS. Notably, 10 aroma-active compounds and 9 volatiles were identified by GC × GC-O-TOF-MS and HS-GC-IMS for the first time. The AEDA and OAVs results indicated that β-damascenone, linalool, 3-ethylbutanoic acid, and nonanal were the most powerful aroma-active compounds. These findings will provide deeper insights into improving the sensory quality of tomato paste.
•Strawberry sensory quality were maintained well by superatmospheric oxygen (90% O2).•Superatmospheric oxygen inhibited decay development of strawberry during storage.•Superatmospheric oxygen ...minimized the postharvest loss of aroma flavor in strawberry.•Superatmospheric oxyge had a beneficial effect on the content of DMHF and γ-decalactone.
The effect of superatmospheric oxygen exposure on the sensory quality, decay incidence, total phenolics, antioxidant capacity, aroma volatiles of strawberries during storage at 0 °C were explored. Freshly harvested strawberry fruits were stored under modified atmosphere 1 (MA1, 90% O2/10% N2), modified atmosphere 2 (MA2,3% O2/5% CO2/92% N2) and control (CT, air). The exogenous superatmospheric oxygen (MA1) had a beneficial effect on maintaining sensory quality and strawberry firmness, and reduced the decay incidence. Titrable acidity and total soluble solid were only slightly affected by superatmospheric oxygen atmosphere. Additionally, superatmospheric oxygen exposure maintained higher levels of total phenolics content and antioxidant capacity than that of CT. Strawberries stored in superatmospheric oxygen emitted more esters, 4-methoxy-2,5-dimethyl-3(2H)-furanone (DMHF) and γ-decalactone. In conclusion, superatmospheric oxygen exposure could be a good alternative for maintaining sensory quality, antioxidant capacity, and aroma volatiles of strawberry.
The popularity of texiang aroma type baijiu (liquor), known for its unique production technology and multilayered flavor, has been steadily increasing among consumers. So far, no research has ...determined its key aroma compounds for characterizing the unique flavor, which is the purpose of this paper. Using gas chromatography–olfactometry (GC–O) coupled with the GC–mass spectrometry (GC–MS) method, 87 aroma-active compounds were identified and screened out with intensity values ≥2.0. 1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) was first confirmed by GC–O in Chinese liquor. According to a quantitative study and odor activity values (OAVs), 42 odorants were determined as important aroma compounds. These odorants were recombined based on quantitative concentrations, successfully simulating the overall aroma profile. Omission experiments verified ethyl hexanoate, β-damascenone, and 2-furfuryl ethyl ether as the key aroma compounds and revealed that ethyl acetate, furfural, and ethyl 2-phenylacetate were important aroma compounds to the overall flavor of texiang aroma and flavor type liquor.
The natural fermentation of cigar tobacco leaves usually utilizes natural temperature and humidity for fermentation. Cigars produced in China are often fermented in winter, and the low environmental ...temperatures can lead to slow heating of the tobacco stack, affecting the cigar tobacco leaves quality. This study aimed to determine the minimum chamber temperature required to initiate the process of fermentation for cigar tobacco leaves and to explore the impact of temperature on the microbial community of tobacco leaves. Here, the cigar variety “Dexue 1” were subjected to stacking fermentation under three temperature parameters (20 ℃, 27 ℃, 34 ℃). With an increase in environmental temperature, the temperature inside the stack of cigar leaves increased significantly, the protein, total sugar, starch, and total alkaloid content in fermented tobacco leaves decreased, and the aroma components and amino acid content increased. Microbial richness and community diversity associated with fermented tobacco were highest at chamber temperatures of above 27 ℃. The relative abundance of
Chryseobacterium
and
Rhodococcus
was significantly negatively correlated with protein, alkaloids, total sugar, and starch, and positively correlated with amino acids and aroma components.
Chryseobacterium
and
Rhodococcus
may be responsible for the degradation of macromolecular substances and the conversion of favorable aromatic substances, thus improving the tobacco leaves quality. This study demonstrated that increasing the fermentation chamber temperature above 27 ℃ was conductive to raising the inner-stack temperature, increased microbial diversity and aromatic quality, reduced the strength and irritation, and extremely enhanced the overall quality of fermented cigar tobacco leaves.
Key points
•
The environmental temperature of the fermentation chamber has a significant impact on the quality of tobacco
•
Temperature
>
27 ℃ can initiate the process of cigar tobacco leaves fermentation and increase inner-stack temperature and microbial diversity and abundance
•
Chryseobacterium and Rhodococcus may be related to the degradation of macromolecular substances and the transformation of aromatic substances, thereby improving the quality of tobacco leaves
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