Advancements and challenges for brewing aroma-enhancement fruit wines: Microbial metabolizing and brewing techniques.

Aroma, a principal determinant of consumer preference for fruit wines, has recently garnered much attention. Fruit wines brewing was concomitant with complex biochemical reactions, in which a variety of compounds jointly contribute to the aroma quality. To date, the mechanisms underlying the synthesis of aroma compounds and biological regulation methods in fruit wines have remained ambiguous, hindering the further improvement of fruit wines sensory profiles. This review provides a detailed account of the synthesis and regulatory mechanisms of typical aroma compounds and their contributions to the characteristics of wines. Additionally, Comprehensive involves between microflora and the formation of aroma compounds have been emphasized. The microflora-mediated aroma compounds evolution can be controlled by key fermentation techniques to protect and enhance. Meanwhile, the genes impacting key aroma compounds can be identified, which provide references for the rapid screening of aroma-enhanced strains as well as target formation of aroma by modifying relative genes.

Genome-wide characterization of single-stranded DNA in rice.

Single-stranded DNA (ssDNA) is essential for various DNA-templated processes in both eukaryotes and prokaryotes. However, comprehensive characterizations of ssDNA still lag in plants compared to non-plant systems. Here, we conducted in situ S1-seq (ISS1-seq), with starting gDNA ranging from 5 µg to 250 ng, followed by comprehensive characterizations of ssDNA in rice (Oryza sativa L.). We found that ssDNA loci were substantially associated with a subset of non-B DNA structures and functional genomic loci. Subtypes of ssDNA loci had distinct epigenetic features. Importantly, ssDNA may act alone or partly coordinate with non-B DNA structures, functional genomic loci, or epigenetic marks to actively or repressively modulate gene transcription, which is genomic-region-dependent and associated with the distinct accumulation of RNA Pol II. Moreover, distinct types of ssDNA had differential impacts on the activities and evolution of TEs (especially common or conserved TEs) in the rice genome. Our study showcases an antibody-independent technique for characterizing non-B DNA structures or functional genomic loci in plants. It lays the groundwork and fills a crucial gap for further exploration of ssDNA, non-B DNA structures, or functional genomic loci, thereby advancing our understanding of their biology in plants.

Identification and map-based cloning of long glume mutant gene lgm1 in barley.

The spikes of gramineous plants are composed of specialized units called spikelets. Two bracts at the spikelet bases are known as glumes. The spikelet glumes in barley are degenerated into threadlike structures. Here, we report a long glume mutant, lgm1, similar in appearance to a lemma with a long awn at the apex. Map-based cloning showed that the mutant lgm1 allele has an approximate 1.27 Mb deletion of in chromosome 2H. The deleted segment contains five putative high-confidence genes, among which HORVU.MOREX.r3.2HG0170820 encodes a C2H2 zinc finger protein, an ortholog of rice NSG1/LRG1 and an important candidate for the Lgm1 allele. Line GA01 with a long glume and short awn was obtained in progenies of crosses involving the lgm1 mutant. Interestingly, lsg1, a mutant with long glumes on lateral spikelets, was obtained in the progenies of the lgm1 mutant. The long glume variant increased the weight of kernels in the lateral spikelets and increased kernel uniformity across the entire spike, greatly improving the potential of six-rowed barley for malting. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01448-x.

The role of Arabic gum on astringency by modulating the polyphenol fraction-protein reaction in model wine.

The potential contribution of Arabic gum to wine astringency was discussed in this study. Two universally used Arabic gum (concentration of 0.2-1.2 g/L) were investigated in model wine based on the polyphenol fractions (phenolic acids, monomeric/oligomeric, and polymeric procyanidin) and protein interaction system. Both physicochemical analyses and sensory evaluation revealed that the modulation of Arabic gum on astringency was affected by the structural properties and concentration of Arabic gum and polyphenolic fractions. Arabic gum at 0.2 g/L appeared as the optimal dose to reduce astringency compared to 0.6 and 1.2 g/L. It inhibited astringency induced by polymeric procyanidin more than that of oligomeric procyanidins and phenolic acids mainly by forming soluble ternary complexes with polyphenols and proteins, and preferentially binding proteins/polyphenols to decrease polyphenol-protein reactions. Arabic gum also inhibited the self-aggregation of polyphenols, exhibiting more binding sites when its higher molecular weight and more/longer branches, leading to competition with polyphenols for bind proteins.

Investigating wine astringency profiles by characterizing tannin fractions in Cabernet Sauvignon wines and model wines.

Contribution of various phenols on wine astringency profiles was far from clear explanations. To effectively describe wine astringency profiles and determined the function of tannins/matrix (pH and ethanol), multiple chemical analyses combined RATA (Rate-all-that-apply) sensory method were applied in Cabernet Sauvignon and model wines. Results showed that polymeric flavanols determined the bulk of wine astringency intensity, oligomeric tannins enriched the smoothness and periodontium astringency, and monomeric phenol enhanced overall astringency intensity through synergistic effect. Astringency balance was effectively quantification, and its potential correlation relationship with epicatechin extension subunit (0.83) and fluorescence peak shift (0.75) cannot be ignored. The astringency profiles of condensed tannins with anthocyanins were enhanced. Low-pH (from 3.8 to 3.0) enhanced astringency by increasing the tannins affinity to proteins, while ethanol (from 10.0 % âˆ¼ 15.0 %) decreased the hydrophobicity bond between tannins-protein interaction. This paper provided new insights to explain wine astringency profiles and a reference for astringency modification during winemaking.

Mannoproteins, arabinogalactan protein, rhamnogalacturonan II and their pairwise combinations regulating wine astringency induced by the interaction of proanthocyanidins and proteins.

Roles of polysaccharides on modulating wine astringency from the perspective of polyphenol-proteins interaction has received increasing attention in last decade. In this work, proanthocyanidins extracts from three wines with different polyphenolic profiles and organoleptic properties were prepared to establish polyphenol-proteins interaction model wines. The effect of three wine polysaccharides including mannoproteins (MP), arabinogalactan protein (AGP) and rhamnogalacturonan II (RG-II) as well as their pairwise combinations on the interaction model wines were evaluated. Results showed that the structure and concentration of proanthocyanidins and polysaccharides had great influence on astringency. Proanthocyanidins with high mean degree of polymerization generated stronger astringency than others. Combining the results of fluorescence quenching and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, RG-II and other two polysaccharides (MP and AGP) modulated astringency through forming a ternary complex and competing reaction, respectively. Owing to synergetic effects, pairwise combinations of three polysaccharides (especially AGP + RG-II) reduced astringency more significantly than individual polysaccharides. Lower concentration (0.2 g/L-0.6 g/L) polysaccharides showed great contribution in modulating astringency. Sensory evaluation also verified the above-mentioned results. These findings were supposed to help better understand changes of astringency perception owing to the interaction of macromolecular substances in wine.

Investigating the role of tartaric acid in wine astringency.

Previous studies acknowledged that tartaric acid-imparted low-pH contributed to the enhancement of astringency, but in-depth studies are lacking and the underlying mechanisms are not clearly understood. This work introduced new insight into the effect of tartaric acid on astringency perception from the perspectives of complex formation, protein secondary structure, chemical bond type and salivary layer fluidity by establishing models using proteins (α-amylase, salivary proteins) and tannic acid. Results demonstrated that tartaric acid affects wine astringency by two mechanisms: a) Tartaric acid compound directly affects the wine astringency by forming ternary complexes and causing the protein structure to stretch by changing the hydrogen bond and hydrophobic bond between protein-polyphenol complexes. b) pH affected astringency by increasing the fluidity of the salivary layer rather than increasing the consumption of the salivary layer. The findings provide valuable information to the wine industry to regulate wine astringency by the management of tartaric acid.

Developing novel oenological tannins from 44 plants sources by assessing astringency and color in model wine.

BACKGROUND: Oenological tannins are commercial natural products extracted from different botanical sources, which were widely reported as prominent contributors to wine quality. Research on wine quality affected by tannins extracts promoted the development of new oenological products with low cost and high accessibility. In the present study, the structure and concentration of tannin in polyphenol extracts, as well as their correlation with astringency and the color of model wine, was investigated by UV spectrophotometer, HPLC, fluorescence quenching, sodium dodecylsulfate-polyacrylamide gel electrophoresis, colorimeter and sensory evaluation. RESULTS: Resource extracts from 16 of 44 plants were screened as wine oenological tannins, according to the total polyphenol and total flavanol, as well as the intensity of astringency and bitterness. Polyphenols extracted from grape seeds and green tea were more effective in increasing the wine astringency compared to other plant tannins. CONCLUSION: Total flavanol content and tannin activity showed a strong correlation with wine astringency. Condensed tannins with mean degree of polymerization also exhibited strong color stability, and the concentrations of (-)-epigallocatechin were associated with the a* value, a negative qualitative factor for wine color. The present study provides new clues regarding the development of low-cost and highly accessible sources of polyphenol extracts and lays a theoretical foundation for the development of the oenological product. © 2022 Society of Chemical Industry.

Investigating the effect of three phenolic fractions on the volatility of floral, fruity, and aged aromas by HS-SPME-GC-MS and NMR in model wine.

In this study, the volatility of three typical wine aromas in model wine was investigated by HS-SPME-GC-MS, NMR, and sensory evaluation as influenced by different concentrations and structural properties of phenolics. Results showed that three phenolic fractions (phenolic acids, monomeric/oligomeric and polymeric procyanidins) exhibited different matrix effects on floral, fruity, and aged aromas perception. Physico-chemical and sensory analyses together indicated that all fractions reduced the perceived intensity of fruity and aged aroma attributes, and displayed stronger retention effects on fruity aromas at higher mDP and concentrations. Monomeric/oligomeric and polymeric procyanidins promoted highly hydrophobic floral aromas release, whereas inhibiting the volatility of low hydrophobic fruity aromas. NMR confirmed that the reduction in the volatility of rose oxide, ethyl butanoate and whiskey lactone was attributed to interactions with epicatechin. This study aims to provide new thoughts and theoretical support for wine aroma regulation during winemaking by reconstructing the phenolic composition in wine.

Efficacy and safety of AnluoHuaxian pills on chronic hepatitis B with normal or minimally elevated alanine transaminase and early liver fibrosis: A randomized controlled trial.

ETHNOPHARMACOLOGICAL RELEVANCE: The AnluoHuaxian pill (AHP) is a widely used patented medicine for chronic hepatitis B (CHB) patients with advanced fibrosis or cirrhosis that has been used in China for more than 15 years. However, data are lacking on whether monotherapy with AHP can be effective in CHB patients with alanine aminotransferase (ALT) levels less than 2 times the upper limit of normal (ALT<2ULN) and early liver fibrosis (F ≤ 2). AIM OF THE STUDY: We aimed to investigate whether monotherapy with AHP improves liver histology in these patients. MATERIALS AND METHODS: In this double-blind, randomized, placebo-controlled trial, 270 CHB patients with ALT<2ULN and F ≤ 2 were treated in 12 hospitals in China. The patients were randomly assigned to an intervention (AHP) group and a placebo group at a ratio of 2:1. Of these 270 enrolled patients, 147 had paired liver biopsies. The primary end point was histological change after 48 weeks of treatment. RESULTS: Per-protocol analysis revealed that the rate of histologic improvement in liver fibrosis patients in the AHP group was significantly higher than that in the placebo group (37.7% vs. 19.5%, P = 0.035) after 48 weeks of treatment, which was consistent with results from intention-to-treat and sensitivity analyses. Moreover, after adjusting for baseline characteristics, AHP was superior to placebo with respect to improving liver fibrosis (odds ratio [OR] = 2.58, 95% confidence interval [CI]: (1.01, 6.63),P = 0.049) and liver histology (OR = 3.62, 95% CI: (1.42, 9.20),P = 0.007). In noninvasive measurement of liver fibrosis (FibroScan®), the level of liver stiffness measurement (LSM) had decreased significantly at 48 weeks (5.1 kPa) compared with that at baseline (5.7 kPa) (P = 0.008) in the AHP group, whereas it did not decrease significantly in the placebo group. Cirrhosis developed in one patient in the placebo group but in no patients in the AHP group. No serious side effects occurred in the AHP-treated patients. CONCLUSIONS: Treatment of CHB patients who had ALT<2ULN and F ≤ 2 with the traditional Chinese medicine AHP for 48 weeks improves liver fibrosis. However, due to the short duration of treatment and the limited sample size of liver pathology, the long-term benefits of AHP in reducing fibrosis and the risk of cirrhosis and hepatocellular carcinoma in these patients need to be further studied in the future.

Evolution of typical aromas and phenolic compounds of a red-fleshed apple throughout different fruit developmental periods in Xinjiang, China.

Red-fleshed apple is attracting more and more attentions from both consumers and researchers thanks to its pleasant appearance and flavor. Accumulation and development of aromas of apple fruit are important factors to understand the fruit quality of a new cultivated variety. However, knowledge on the key aroma components development and accumulation of red-fleshed apple (Malus sieversii f. neidzwetzkyana(Dieck) Langenf) in Xinjiang through the fruit developmental periods is insufficient. In this paper, free and bound form aromas of a red-fleshed apple since young fruit period through expansion period and conversion period to ripen period were comparatively studied. We classified aroma substances according to the compound category (esters, aldehydes, alcohols, terpenes, and aromatics), and to the odor types. The concentration of bound form aroma compounds were higher than that of free form throughout the 4 periods and showed different evolution trends. Among the 4 periods, the bound aroma was the most in the expansion period; and terpenoids showed the greatest potential to release free form aromas. Total aromas were found the lowest concentration in expansion period and the highest concentration in ripen period. The observations in this study will provide theoretical support for the research of typical aroma formation regularity of red-fleshed apple, and guide for the aroma enhancement regulation.

Thinned-Young Apple Polyphenols Inhibit Halitosis-Related Bacteria Through Damage to the Cell Membrane.

The thinned young apple is a by-product and is generally discarded in the orchard during fruit thinning. The polyphenol content of thinned young apples is about 10 times more than that of ripe apples. In our study, the antibacterial effect of thinned young apple polyphenols (YAP) on the halitosis-related bacteria including Porphyromonas gingivalis, Prevotella intermedius, and Fusobacterium nucleatum was investigated. The minimum inhibitory concentrations of YAP against P. gingivalis, P. intermedia, and F. nucleatum were 8.0, 8.0, and 12.0 mg/ml, while the minimum bactericidal concentrations were 10.0, 10.0, and 14.0 mg/ml, respectively. The scanning electron microscopy and transmission electron microscopy analyses showed that after YAP treatment, the membrane surface of halitosis-related bacterial cells was coarse and the cell wall and membrane were separated and eventually ruptured. The integrity of the cell membrane was determined by flow cytometry, indicating that the cells with the integrity membrane significantly reduced as the YAP concentration treatment increased. The release of proteins and nucleic acids into the cell suspension significantly increased, and the membrane potential reduced after the YAP treatment. This research illustrated the antibacterial mechanism of YAP against halitosis-related bacteria and provided a scientific basis of utilizing the polyphenols from the discarded thinned young apples.

Effect of free amino acids and peptide hydrolysates from sunflower seed protein on the formation of pyrazines under different heating conditions.

Most research concerning pyrazine formation in the Maillard reaction is mainly focused on free amino acids (FAAs), but limited information is available on the effect of peptides and proteins. In this study, three Maillard model systems (i.e., glucose and native sunflower seed protein, hydrolyzed peptides or FAAs, respectively) were prepared, and their effect on the formation of volatiles were further compared at different heating conditions by using of headspace solid-phase microextraction equipped with gas chromatography/mass spectrometry (HS-SPME-GC/MS). It was found that pyrazines were the characteristic volatile compounds in tested Maillard models, and with increasing heating temperature and time, the varieties of pyrazine formation significantly increased. The optimum reaction condition for pyrazine formation was at 140 °C for 90 min, which was subsequently applied to all sets of Maillard models. Further analysis showed that the short chain peptides generated by hydrolyzing sunflower seed protein (SSP), especially the molecular weight ranging from 1.2 to 3.0 kDa, significantly promoted the formation of pyrazines, which highlights the important role of peptides in the Maillard reaction models and is expected to intensify aroma promotion in sunflower seed oil.

Differences in MicroRNA Expression in Chronic Hepatitis B Patients with Early Liver Fibrosis Based on Traditional Chinese Medicine Syndromes.

The aim of this study was to determine if microRNA (miRNA) expression is different among chronic hepatitis B (CHB) patients with early liver fibrosis classified according to traditional Chinese medicine (TCM) syndromes. Eighteen CHB-fibrosis patients and 12 CHB patients without fibrosis were enrolled. The CHB-fibrosis group included 9 patients with the TCM syndrome of Ganyu Pixu Xueyu (GYPXXY), characterized by liver stagnation, spleen deficiency, and blood stasis, and 9 patients with the TCM syndrome of Qixu Xueyu (QXXY), characterized by deficiency of qi, blood, and blood stasis. Agilent miRNA microarray was performed first in liver specimens to determine whether miRNA expression is different in patients with these two TCM syndromes of CHB-fibrosis. Gene Ontology (GO) analysis and KEGG analysis were applied to determine the roles of the differentially expressed miRNAs. QRT-PCR was performed to validate the Agilent miRNA microarray results. Compared with GYPXXY patients, 6 differentially expressed miRNAs were upregulated (miR-144-5p, miR-18a-5p, miR-148b-3p, miR-654-3p, miR-139-3p, and miR-24-1-5p) and 1 was downregulated (miR-6834-3p) in QXXY patients. According to qRT-PCR data, miR-144-5p and miR-654-3p were confirmed as upregulated in CHB-liver fibrosis patients compared to CHB patients without fibrosis, whereas the other 4 miRNAs were not significantly different. More importantly, miR-654-3p was confirmed to be significantly upregulated in QXXY patients compared with values in GYPXXY patients, whereas no significant difference was found in miR-144-5p. Moreover, the pathways of central carbon metabolism in cancer and cell cycle related to miR-654-3p and the target genes of PTEN and ATM were found to be different between QXXY patients and GYPXXY patients. These results indicate that there are different miRNAs, pathways, and target genes between QXXY patients and GYPXXY patients. However, due to the limited sample, whether miR-654-3p and the target genes PTEN and ATM could be molecular markers to differentiate TCM syndromes could not be established.

Testicular Lmcd1 regulates phagocytosis by Sertoli cells through modulation of NFAT1/Txlna signaling pathway.

Increased oxidative stress is well known to cause testicular dysfunction in aging males, but the detailed relationships between aging, oxidative stress, and testicular function remain to be elucidated. LIM and cysteine-rich domains 1 (LMCD1) regulates fundamentally cellular process by interacting with transcription factors. A recent study has identified Lmcd1 as one of the most upregulated nuclear proteins associated with Sertoli cell (SC) differentiation, raising the possibility that testicular actions of LMCD1 are likely to take place. Herein, we reported that LMCD1 was exclusively expressed in the nuclei of SCs. This expression was regulated by TNF-α signaling produced by apoptotic germ cells (GCs) and was suppressed by oxidative stress in a STAT3-dependent manner. Ablation of endogenous LMCD1 expression caused lipid accumulation and senescence in GC co-incubated SCs. Using a previously validated in vivo siRNA approach, we showed that LMCD1 depletion significantly impaired male fertility by inducing oligozoospermia and asthenospermia. Mechanistically, LMCD1 upregulation was associated with the nuclear enrichment of the nuclear factor of activated T cells 1 (NFAT1), a core component of Ca2+ /calmodulin-dependent pathway. LMCD1 facilitated the dephosphorylation and nuclear translocation of NFAT1, which consequently expedited the transactivation of Txlna, a binding partner of the syntaxin family essential for testicular phagocytosis, and thus promoted the removal of apoptotic GCs by phagocytic SCs. Collectively, LMCD1 may operate as a novel pretranscriptional integrator linking SC phagocytosis, lipid homeostasis, and cell senescence.

Wine polysaccharides modulating astringency through the interference on interaction of flavan-3-ols and BSA in model wine.

Polysaccharides and flavan-3-ols from Cabernet Sauvignon wine were isolated and then characterized by high performance liquid chromatography coupled with diode array detector (HPLC-DAD), high performance size exclusion chromatography (HPSEC) and HPLC-MS. The influence of purified polysaccharides on the aggregation of flavan-3-ols-proteins were investigated using fluorescence spectroscopy, circular dichroism (CD) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to evaluate the co-effect of polysaccharides on wine astringency. The results indicated that mannoproteins (MPs) and rhamnogalacturonans II (RG II) were the major polysaccharides to significantly alter the interaction of flavan-3-ols with bovine serum albumin (BSA). The interaction of polysaccharides-flavan-3-ols-BSA was enhanced with the concentration (from 0.2 to 0.6 g/L) of the studied polysaccharides. Furthermore, the reaction of BSA-flavan-3-ols was strengthened in the absence of polysaccharides when percentage of galloylation (%G) was higher (11.29). When mean degree of polymerization (mDP) of flavan-3-ols was from 5.14 to 6.88, the secondary structure of proteins was changed from mainly α-helix to random curl and the formation of protein precipitation increased. This work pointed out that the important property of polysaccharides and different structural characteristic flavan-3-ols are able to modulate wine astringency perception.

Histological improvement in chronic hepatitis B patients treated with bicyclol: real world experience.

BACKGROUND: Bicyclol, the most commonly-used liver hepatoprotective drug in China, is often selected to control disease progression in CHB patients who refuse anti-viral treatment. However, data on histological changes after bicyclol treatment in these patients are scarce. Therefore, this study has been conducted to find out whether bicyclol has good benefits of histological improvement in CHB patients who refuse anti-viral agents. METHODS: The demographic, clinical and pathological data were collected from CHB patients who received bicyclol from January 2010 to June 2016. Improvement in liver inflammation or fibrosis is defined as at least one-grade or one-stage decrease as measured by the Scheuer scoring system. Thirty patients treated with ETV for 48 weeks were chosen as a control group to compare the histological improvement between bicyclol and entecavir (ETV) after 48-week treatment. RESULTS: A total of 123 patients with CHB treated with bicyclol were included in this study. Paired liver biopsies were performed in 70 patients. Inter-biopsy interval was 17.44 ± 8.90 months (12-60 months). As shown by facts, 41.4% patients achieved liver inflammation improvement, while only 10.0% patients showed liver inflammation progression after bicyclol treatment. In regarding to liver fibrosis, as shown by facts, 28.6% patients achieved fibrosis improvement. More importantly, It was found that the proportions of patients with liver inflammation and fibrosis improvement were both not significantly lower than those in ETV group (53.3% vs 63.3 and 36.7% vs 43.4%). Most of patients (82.4%) with elevated baseline ALT became normal after bicyclol treatment. More importantly, as shown by the multi-variate analysis, the treatment course of bicyclol was an independent factor for liver inflammation improvement. With the HBeAg status adjusted, ALT and HBV-DNA quantity, the odds ratio (95% confidence interval) of patients with ≥48-week treatment was 5.756 (1.893,17.500) when compared with patients via < 48-week treatment. CONCLUSION: Bicyclol can improve liver inflammation and the ALT normalization rate of CHB patients, especially when the treatment course is prolonged. This has confirmed that bicyclol could control hepatitis activity, which might be a good choice for CHB patients who refuse anti-viral treatments.

Automatic regulation of NF-κB by pHSP70/IκBαm to prevent acute lung injury in mice.

Controlling target gene expression is a vital step in the procedure of gene therapy upon acute lung injury (ALI). Excessive activation of nuclear factor-kappa B (NF-κB) has been the key point of the inflammation overwhelming process in onset of ALI. We designed and tested a variety of plasmid named pHSP70/IκBαm which conditionally carries a mutant inhibitor of kappa B (IκB) transgene to regulate the activity of NF-κB signaling pathway in its response to an inflammatory stimulus that causes acute lung injury. Results recorded along our experiments showed that pHSP70/IκBαm was able to control mutant IκB expression in RAW264.7 cells with reference to the level of inflammatory response induced by LPS, thereby inhibiting NF-κB activation and downstream inflammatory cytokine expression. Vivo experiments revealed that construction naming pHSP70/IκBαm reduced LPS-induced lung injury and the secretion of inflammatory factors from lungs, hearts, and livers of sample mice in a LPS dose-dependent manner. In conclusion, the promoter heat shocking protein 70(HSP70) regulatory sequence of the construction was shown to drive mutant IκB expression so that its levels were positively associated with the dose of LPS used to induce acute lung injury. NF-κB activation and the downstream expression of inflammatory factors were therefore down-regulated in along an efficient path and ameliorating the damage as a consequence of LPS-induced acute lung injury.

Characterization of the Key Aroma Compounds in Chinese Syrah Wine by Gas Chromatography-Olfactometry-Mass Spectrometry and Aroma Reconstitution Studies.

The key aroma compounds and the organoleptic quality of two Chinese Syrah wines from the Yunnan Shangri-La region and Ningxia Helan mountain region were characterized. The most important eighty aroma-active compounds were identified by Gas Chromatography-Olfactometry. In both Syrah samples, ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, 3-methylbutyl acetate, 2- and 3-methyl-1-butanol, ethyl hexanoate, ethyl octanoate, 2-phenethyl acetate, methional, 3-methylbutanoic acid, hexanoic acid, octanoic acid, ß-damascenone, guaiacol, 2-phenylethanol, trans-whiskylactone, 4-ethylguaiacol, eugenol, 4-ethylphenol, and sotolon were detected to have the highest odor intensities. In the chemical analysis, 72 compounds were quantitated by Stir Bar Sorptive Extraction combined with Gas Chromatography Mass Spectrometry. Based on the Odor Activity Value (OAV), the aromas were reconstituted by combining aroma compounds in the synthetic wine, and sensory descriptive analysis was used to verify the chemical data. Fatty acid ethyl esters, acetate esters, and ß-damascenone were found with higher OAVs in the more fruity-smelling sample of Helan Mountain rather than Shangri-La.