Search Results (658)

Four sweet cherry cultivars (FuChen, Redlight, Huangmi, and Samituo) grown in northern China were used to produce sweet cherry wines with two alcohol levels. Physicochemical properties, antioxidant capacity, and volatile aroma compounds of the wines were systematically investigated. The results showed that wine from the Redlight cultivar with an alcohol content of 11.22 ± 0.17% contained the highest phenolic content and also exhibited the strongest antioxidant capacity as measured by DPPH and ABTS•⁺ assays. Meanwhile, wine from the FuChen cultivar with an alcohol content of 11.45 ± 0.03% had the highest anthocyanin content and showed the strongest FRAP antioxidant activity. Orthogonal partial least squares discriminant analysis (OPLS-DA) based on electronic nose data clearly distinguished the eight sweet cherry wine samples from different cultivars. A total of 58 volatile compounds were identified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Both principal component analysis (PCA) and OPLS-DA revealed clear differences among the sweet cherry wines based on their volatile composition. Using variable importance in projection (VIP) scores > 1 and relative odor activity values (ROAVs), the key aroma compounds contributing to the characteristic aroma profiles of the eight sweet cherry wines were identified as ethyl butanoate, isoamyl acetate, isoamyl hexanoate, methyl decanoate, ethyl decanoate, ethyl benzoate, methyl salicylate, citronellol, and eugenol. These findings provide important guidance for the selection of raw materials to improve the production of sweet cherry wines with targeted alcohol levels. Full article

To reveal how the characteristic flavor of jasmine tea is generated, this study analyzed the coordinated changes in sensory properties, chemical components, and aroma migration behavior during scenting. Sensory evaluation, biochemical assays, and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) integrated with orthogonal partial least squares discriminant analysis (OPLS-DA) and relative odor activity value (rOAV) filtering were applied to tea samples before and after scenting. After scenting, aroma and taste scores increased significantly, and liquor color shifted from tender green to pale yellow. Amino acids and soluble sugars increased, while astringent substances such as tea polyphenols and catechins decreased. Key floral compounds, including cis-3-hexenyl benzoate and methyl anthranilate, were transferred from jasmine flowers to the tea base and enriched, likely contributing to the typical aroma profile. The retention rate of aroma in spent flowers was positively correlated with hydrophobicity (logP, r > 0.46, p < 0.01) and negatively with polarity (TPSA, r > −0.42, p < 0.05), suggesting regulation by hydrophobic partitioning. In contrast, aroma transfer to the tea base showed no simple correlation with any single physicochemical parameter, suggesting multi-factor regulation. This study provides insights into the scenting process and offers a theoretical reference for quality control in jasmine tea production. Full article

Thamnaconus modestus (black scraper) is an economically important fish species in Chinese coastal fisheries, yet its pronounced fishy off-odor, primarily attributed to sulfur-containing compounds and trimethylamine (TMA), severely limits consumer acceptance and product diversification. However, a systematic investigation into how different thermal processing methods affect its volatile flavor profile is lacking. This study employed an integrated multi-instrumental flavoromics platform combining sensory evaluation, electronic nose (E-nose), electronic tongue (E-tongue), gas chromatography–ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS), coupled with chemometric analysis, to systematically characterize the aroma variations of T. modestus subjected to steaming, boiling, deep-frying, and roasting treatments compared with raw samples. A total of 62 (GC-IMS) and 129 (GC-MS) volatile compounds were identified, from which 78 characteristic markers (VIP > 1) and 45 key odorants (OAV ≥ 1) were screened. Thermal processing markedly reduced sulfur-containing compounds and TMA concentrations (raw >> steamed ≈ boiled >> deep-fried > roasted) while promoting lipid oxidation- and Maillard reaction-derived aldehydes and furans. Two distinct flavor modulation patterns were revealed: moist-heat methods (steaming, boiling) generated grassy/fatty notes through moderate lipid oxidation, whereas dry-heat methods (deep-frying, roasting) produced characteristic roasted/nutty notes via synergistic activation of Strecker degradation and Maillard reaction. These findings provide scientific evidence for precise flavor quality control and diversified processing optimization of T. modestus products. Full article

This study systematically investigated differences in volatile flavor profiles among fermented green plum wines by integrating gas chromatography–mass spectrometry (GC–MS), sensory evaluation, and odor activity value (OAV) analysis with machine learning and SHapley Additive exPlanations (SHAP) based feature interpretation. The primary objective was to evaluate the applicability of machine learning algorithms for flavor profiling of green plum wine. The results indicated that floral and fruity aromas were predominant in samples NG9, YM7, and YM9. Most green plum wines contained high levels of esters, with ethyl benzoate (up to 4820.53 μg/L), ethyl octanoate (up to 2640.83 μg/L), and benzenecarbaldehyde (up to 3432.96 μg/L) being the major contributors. Among the six classification algorithms compared, fuzzy c-means clustering provided the most distinct clustering structure, identifying three distinct flavor categories. Six machine learning models were subsequently established, of which the decision tree (DT) model exhibited the highest performance, with an accuracy of 95.13%. SHAP analysis further revealed that ethyl octanoate, benzyl ethanoate, and 2-phenylethyl ethanoate exerted the greatest influence on model predictions. Overall, these findings highlight the effectiveness of machine learning as a robust tool for the classification and interpretation of flavor characteristics in fermented fruit wines, with broad applicability in flavor science. Full article

This study investigated the valorization of chicken feet, an underutilized poultry by-product, through enzymatic hydrolysis to obtain a protein hydrolysate with improved functional properties. Enzymatic treatment was carried out using Enzy-Mix U100 and collagenase from Streptomyces lavendulae, with cheese whey applied as a process medium. The resulting protein hydrolysate contained 59.1% protein and was characterized by high levels of glycine (31.64 g/100 g protein), hydroxyproline (10.91 g/100 g protein), and alanine (10.58 g/100 g protein). The hydrolysate exhibited strong techno-functional performance, with a water-binding capacity of 580%, an emulsifying activity index of 166 m²/g, and an emulsion stability index of 31 min. Microstructural analysis revealed irregular porous particles typical of freeze-dried protein hydrolysates, reflecting structural modification of collagen during enzymatic treatment. Mineral analysis showed notable levels of sodium (463.1 mg/100 g) and magnesium (351.8 mg/100 g). Microbiological evaluation demonstrated high sanitary quality, with a total viable count of 100 CFU/g and absence of coliforms, Escherichia coli, yeasts, and molds in 1 g of product. The technological process reduced the characteristic odor of chicken feet while maintaining a light color and good dispersibility. These findings confirm the potential of enzymatic hydrolysis as a sustainable strategy for converting poultry by-products into safe, value-added functional protein ingredients for food applications. Full article

Satellite remote sensing offers a cost-effective solution for the continuous monitoring of black and odorous water bodies (BOWs). However, limitations in spatial and spectral resolution hinder the quantitative inversion of water quality parameters and the precise assessment of risk levels using satellite data alone. To address this challenge, this study proposes a synergistic approach combining satellite and Unmanned Aerial Vehicle (UAV) remote sensing to rapidly identify potentially polluted water bodies and quantitatively assess their risk levels. First, a Black and Odorous Water Index (MBOWI) was constructed based on reflectance characteristics in the visible to near-infrared bands to screen for potential black and odorous water bodies using satellite imagery. Subsequently, high-resolution multispectral UAV imagery, integrated with in situ sampling data, was employed to develop machine learning models for inverting key water quality parameters, including Chemical Oxygen Demand (COD), Dissolved Oxygen (DO), Total Phosphorus (TP) and Ammonia Nitrogen (NH₃-N). Comparative analysis of Polynomial Regression (PR), Random Forest (RF), and Simulated Annealing-optimized Support Vector Regression (SA-SVR) revealed that RF and SA-SVR exhibited superior performance in inverting four non-optically active water quality parameters due to their robust nonlinear fitting capabilities, with the mean Adjusted Coefficient of Determination ($R_{adj}^2$) ranging from 0.57 to 0.69. Water quality classification based on the single-factor worst-case method achieved an overall accuracy of 0.70 across validation samples. Notably, for Class V (heavily polluted) water bodies, both classification accuracy and recall rate reached 0.89, demonstrating the model’s high precision in identifying high-risk waters. Finally, the proposed framework was applied to northern Zhejiang Province to assess seven potential black and odorous water bodies, successfully identifying four as high-risk and one as low-risk. This study validates satellite and UAV synergistic remote sensing for the hierarchical risk management of black and odorous water bodies. Full article

Gluten-free (GF) products developed for individuals with celiac disease and gluten sensitivity often suffer from low protein and mineral content. Fish proteins offer a promising solution to address these deficiencies; however, the characteristic “fishy odor” and related technological challenges limit consumer acceptance. This study aimed to develop an innovative GF pasta with improved nutritional density and acceptable sensory quality by incorporating deodorized and lyophilized trout powder. GF pasta formulations were prepared using buckwheat flour, xanthan gum, and 5% or 10% odorless trout powder. Vinegar pretreatment was applied to reduce fish odor, while lyophilization was chosen to minimize nutrient losses. The samples were analyzed for nutritional composition, techno-functional properties, in vitro digestibility, and sensory attributes. Results showed that trout powder significantly increased protein and ash content compared to the control (p < 0.05). A slight darkening was observed in color analysis due to fish pigments and buckwheat phenolics, but overall visual stability remained high. In vitro digestibility revealed enhanced protein digestibility (p < 0.05) and a slight reduction in starch digestibility. Sensory evaluation demonstrated that odor scores (8) at 10% trout inclusion remained close to the control, reversing the commonly reported decline in acceptance with increasing fish content. These findings indicate that combining vinegar pretreatment with lyophilization enables the incorporation of fish proteins into GF pasta without sensory disadvantages, while simultaneously improving nutritional quality. Full article

A sustainable way to recycle used tires and improve the functionality of asphalt pavements is through the use of crumb rubber modified asphalt (CRMA). However, its application during high-temperature construction raises environmental and occupational health concerns due to the release of significant quantities of odorous and potentially harmful gases. Therefore, this study selected α-Amyl cinnamic aldehyde (ACA) as a deodorant and added it to CRMA at proportions of 0.5%, 1.0%, 1.5%, and 2.0% to prepare DCRMA. A number of common tests, such as softening point, ductility, penetration, Brookfield rotational viscosity, and segregation analysis, were used to evaluate the basic characteristics of the modified asphalt. A self-developed asphalt fume monitoring device was used to quantitatively analyze the changes in VOCs, H₂S gas concentration, and solid particle content in the asphalt fumes to assess the deodorization effect of ACA on CRMA. Furthermore, the deodorization mechanism of ACA on CRMA was explored in depth using microscopic methods, such as fluorescence microscopy (FM) and Fourier transform infrared spectroscopy (FTIR). The findings demonstrated that ACA can increase the softening point and viscosity of CRMA while decreasing its penetration and ductility. The storage stability was optimal at a 1.0% ACA addition. Additionally, as the ACA content increased, the concentrations of VOCs, H₂S gas, and solid particles in the asphalt fumes continued to decrease. FM results indicated that when the ACA content did not exceed 1.0%, it promoted the swelling degree of CR in the asphalt. FTIR results showed that ACA can reduce the characteristic peak intensity of CRMA. This study offers important technical references and practical support for the environmentally friendly use of CRMA. Full article

Jimo Huangjiu (JMHJ), a Chinese geographical indication product from Shandong Province, is characterized by distinctive burnt-like and smoky aromas. However, the specific odorants responsible for these sensory attributes remain uncharacterized. In this study, the flavor characteristics of Jimo Huangjiu are characterized through static and dynamic sensory evaluation during the drinking process. This study identified the essential odorants of JMHJ through integrated sensomics analysis. Results revealed pyrazines and phenolic compounds as the characteristic aroma markers responsible for the unique smoky and burnt-like aroma of JMHJ. Ethyl 2-methylpropionate, 4-methylphenol, 4-ethyl-2-methoxyphenol, β-phenylethyl alcohol, 2-ethyl-6-methylpyrazine, 2-ethyl-3-methylpyrazine, 2-methylpyrazine, 2-methoxyphenol, 2-methylphenol, 2,3-dimethylpyrazine, and 2-hydroxy-3-methyl-2-cyclopentenone were confirmed as key odorants in JMHJ. Furthermore, the synergistic interactions between nonanoic acid and phenolic compounds were found to contribute to a Qu-like aroma, representing a novel mechanism for this characteristic sensory attribute in Huangjiu. Full article

The sensory quality and flavor of lamb meat, critical to market competitiveness, are influenced by rumen microbial fermentation and dietary management strategies. Coated betaine (CBet), a rumen-protected methyl donor, exerts systemic nutritional regulation in ruminants. This study explored the effects of CBet supplementation on lamb meat quality using 18 Dorset ♂ × Hu sheep ♀ F1 crossbred lambs, randomly assigned to either a control group (basal diet) or a 0.20% CBet-supplemented diet for 60 days (n = 9 per group). The results demonstrated that CBet significantly increased ruminal concentrations of total volatile fatty acids (TVFAs), acetic acid, propionic acid, and butyric acid (p < 0.05). Additionally, CBet supplementation enhanced muscle redness (a*), crude fat, crude ash, heptadecanoic acid (C17:0), and tricosanoic acid (C23:0) (p < 0.05) while decreasing shear force and the concentration of cis-13,16-docosadienoic acid (C22:2) (p < 0.05). Furthermore, CBet elevated characteristic flavor compounds (e.g., nonanal) and their relative odor activity values (ROAVs), and decreased undesirable odors (e.g., dodecanal) (p < 0.05). As illustrated in the graphical abstract, these improvements were mediated through regulatory effects of CBet on rumen microbiota composition, muscle fatty acids, amino acids, and volatile flavor compounds. Specifically, CBet significantly increased the relative abundances of Firmicutes, Proteobacteria, Prevotella, and Bifidobacterium in the rumen (p < 0.05) and altered the Firmicutes/Bacteroidota ratio. In conclusion, dietary supplementation with 0.20% CBet effectively enhances lamb meat quality and flavor, effects closely associated with changes in the abundance of key ruminal microbial taxa. Full article

Parasitoids use different signals to locate their hosts, and these signals can modulate their behavioral decisions. Thus, patch selection and foraging in patches with different characteristics depend on their ability to gather and use such information efficiently. In this study, we evaluated whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae), a natural enemy of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) on tomato plants (Solanum lycopersicum), uses scent cues to select and forage in patches that differ in host density and predation risk. Using choice bioassays in a wind tunnel under a continuous airflow, we recorded selection patch and selection time, as well as foraging parameters, including residence time, oviposition events, and attacks. Our results show that E. eremicus discriminated between sites with and without hosts using scent cues, but discrimination between patches with different host numbers was not detected under our assay conditions. It also distinguished between patches with maximum risk and those without risk, but not between subtle differences in risk. These findings suggest that E. eremicus, responded mainly to contrasting olfactory cues rather than to subtle odor differences. From an applied standpoint, our results motivate deeper investigation into how host- and predator-associated olfactory cues could fine-tune parasitoid deployment in biological control. Full article

Accurate and physiologically relevant in vitro models are needed to predict nutrient digestibility and hindgut fermentation in pigs, as conventional in vivo trials are resource-intensive and raise animal welfare concerns. This study evaluated and compared the predictive performance of three in vitro digestion approaches—shaking (S), dialysis (D), and a combined shaking plus dialysis (SD) method—for estimating in vivo apparent total tract digestibility (ATTD) and fermentation characteristics across weaning, growing, and finishing pigs. Commercial diets were subjected to simulated gastric and small-intestinal digestion using S, D, or SD, followed by fecal inoculation to model hindgut fermentation for 12 and 48 h. During the gastrointestinal phase, crude protein digestibility was highest with D (>75%), intermediate with SD, and lowest with S (50–60%), indicating that product removal by dialysis mitigated enzyme inhibition from metabolite accumulation. After 48 h of fermentation, all methods showed strong linear correlations with in vivo ATTD (r > 0.93), but only D achieved high absolute agreement (Lin’s CCC > 0.95 for dry matter and crude protein). Moreover, D and SD at 48 h closely reflected in vivo fecal profiles of skatole, indole, and microbial enzyme activities, with D at 12 h showing an especially strong correlation for protease (r = 0.98). While D provided the most precise predictions of absolute values, the SD method offered an optimal balance between physiological relevance and operational efficiency, supporting its use as a robust, high-throughput platform for porcine feed evaluation and fecal nitrogenous odorant prediction. Full article

Ripened Pu-erh tea (RPT) experiences notable aroma transformations during industrial pile fermentation, yet the stage-dependent evolution of key aroma compounds remains poorly understood. This study analyzed two independent industrial batches of RPT across three fermentation stages: raw material (RM), intermediate fermentation (IF), and final fermentation (FF). Using HS-SPME/GC-MS coupled with multivariate statistical analysis and relative odor activity values (rOAVs), 134 volatile organic compounds (VOCs) were identified, with hydrocarbons, alcohols, and esters as predominant classes. In total, 13 key aroma-active compounds (rOAVs > 1) were found to be major contributors to RPT’s characteristic aroma. During early fermentation, relative levels of VOCs responsible for fresh and green aromas (e.g., linalool, D-limonene) diminished, while those for woody and minty aromas (e.g., isophorone, methyl salicylate) increased. A flavor wheel was developed to illustrate the dynamic shifts in aroma profiles. This stage-resolved analysis offers new mechanistic insights into aroma formation, aiding in the optimization of aroma quality control and process standardization for RPT production. Full article

Objective: To investigate the epidemiology, clinical characteristics, and potential risk factors of chronic cough following SARS-CoV-2 infection. Methods: A total of 1434 patients with post-COVID-19 cough were categorized into acute, subacute, and chronic subgroups by cough duration, with clinical data analyzed across subgroups. Questionnaire surveys were conducted in chronic cough patients, followed by an 18–21-month follow-up. Results: 1. Significant intergroup differences were observed among the three groups in: the number of patients with rhinitis and/or pharyngitis history, cough with chest tightness, cough with pharyngeal symptoms, and sensitivity to irritating odors and cold air. 2. The chronic group had a significantly lower platelet count but higher eosinophil and basophil percentages than the acute group. 3. The chronic group showed significantly lower values than the subacute group in multiple pulmonary function indices: FVC, FEV1, FEV1/FVC, PEF, MEF25, MEF75, MEF50, MMEF75/25, MEF75%, MEF50%, MEF25%, MMEF75/25%, DLCO, and DLCO%. 4. Chest CT findings: the chronic group had significantly lower rates of infected lesions, cord-like opacities, and ground-glass shadows than the acute group, but a higher rate of micro-nodules than the subacute group. 5. At follow-up, the cough and non-cough groups differed significantly in nighttime cough scores and the proportion of cough with chest tightness, as well as in pulmonary function parameters: FVC, FEV1, PEF, PEF%, MEF75, DLCO, RV% and TLC. 6. Binary logistic regression analysis identified the nocturnal cough symptom score and cough accompanied by chest tightness as independent factors influencing persistent cough 18–21 months after SARS-CoV-2 infection. Conclusions: Patients with pre-existing upper airway inflammation, laryngeal symptoms, chemical hypersensitivity, elevated eosinophil/basophil percentages, and pulmonary micro-nodules are more likely to develop chronic post-COVID cough, presenting with partial ventilatory impairment and diffusing capacity impairments. Full article

This study developed an optimized processing strategy for γ-aminobutyric acid (GABA) instant white tea (GABA-IT) using GABA-enriched white tea as raw material, systematically characterizing its chemical composition and volatile profile. In contrast to the conventional instant tea production process, this work integrates response surface methodology with spray-drying parameter optimization. This integrated approach enables the simultaneous enhancement of functional components and sensory quality. A response surface design was employed to refine the extraction and spray-drying variables following preliminary single-factor trials, and the optimal parameter combination was subsequently determined (40% ethanol concentration, material-to-liquid ratio of 1:15, extraction time of 3 days, atomization speed of 300 rpm, and inlet temperature of 120 °C); the resulting GABA-IT exhibited significantly improved quality characteristics. Specifically, the GABA content increased by 209% (reaching 4.42 mg/g), and theanine, catechins, and caffeine were enriched by 200–300%. Regarding volatile profiles, processing led to a reduction in esters but an increase in aldehydes and hydrocarbons. Relative odor activity value (rOAV) analysis revealed that epoxy-β-ionone and linalool were the key contributors to the characteristic aroma of GABA-IT. Collectively, this study demonstrates the technical feasibility of producing GABA-rich instant tea with enhanced functional components and improved sensory quality, providing practical guidance for the large-scale industrial production of functional tea beverages. Full article