To investigate the changes in volatile flavor compounds in chicken soup during the stewing process of yellow-feathered chicken, headspace solid phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS), electronic nose, and electronic tongue combined with PCA-BP neural network were used to study chicken soup samples at different cooking times (0.5, 1.0, 1.5, 2.0 and 2.5 h). The results showed that as the stewing time increased, the color of the chicken soup became darker. A total of 35 volatile compounds were identified through GC-MS, primarily consisting of aldehydes and alcohols. The total content of volatile flavor compounds increased first and then decreased, and reached a peak after stewing for 2.0 h. GC-MS combined with OAVs value method identified 13 key volatile compounds, including 1-hexanol, 1-octene-3-ol, (E,E)-2,4-decadiena,l (E,E)-2,4-nonadienal, (Z)-2-heptenal, (E)-2-nonenal, (E)-2-octenal, (E)-2-decenal, 2-pentylfuran, heptanal, hexanal, nonanal and octanal. Based on VIP values, 19 characteristic volatile compounds were screened, which could be used to distinguish 5 chicken soup samples. Significant differences in the electronic nose and electronic tongue of chicken soup samples with different stewing times, and these samples could be effectively distinguished by PCA and cluster analysis. The electronic tongue PCA-BP neural network model could accurately predict the stewing time of chicken soup samples and the linear relationship between the true value and the predicted value was good (R²=0.9998). The chicken soup stewed for 2.0 h showed significantly high scores for flavor, color, appearance, and overall acceptability. In conclusion, the optimal stewing time for chicken soup was 2.0 h. The results can be used as the basis for the flavor of the original chicken soup and pave the way for subsequent high-quality Chinese herbal chicken soup research.

This study aimed to investigate the regulatory mechanism of hot air drying at 130 ℃ on the quality characteristics and flavor formation of Grateloupia livida. Drying kinetics, nutritional composition, rehydration capacity, microstructure, and the variation patterns of volatile flavor components and lipid substances were systematically investigated. Results indicated that 130 ℃ hot air drying achieved complete dehydration of G. livida within 24 min, driven primarily by internal moisture diffusion. The dried product exhibited excellent rehydration performance (rehydration ratio: 1200%~1250%), while principal nutrients (e.g. polysaccharides, proteins) were well retained. However, obvious collapse and pore shrinkage occurred in the microstructure. A total of 89 volatile compounds were identified. Among them, the key aroma-active compounds with an odor activity value (OAV)>1 including 1-octen-3-one, (E,Z)-2,6-nonadienal, α-ionone, β-ionone and (E,E)-2,4-nonadienal. Lipidomics analysis detected 3790 lipid species, dominated by saccharolipids (SL), glycerophospholipids (GP) and sphingolipids (SP). Twenty differential lipids (VIP>2), including PG (16:0_21:1)[M+Na]⁺ and PG (18:3_21:1)[M+H]⁺, were screened as potential flavor precursors, participating in thermal oxidative cleavage and Maillard reactions to drive characteristic flavor formation. This study elucidated the influence mechanisms of 130 ℃ hot air drying on the quality of G. livida, providing a theoretical foundation for the development of high-value flavored dried seaweed.

This study aimed to analyze the effects of 10 types of oak chips on the aroma characteristics of strong ale using two descriptive sensory analysis methods, Polarized Projective Mapping (PPM) and Pivot Profile (PP). The results showed that contact with oak chips significantly could enhance the aroma complexity of strong ale and impart typical flavors such as caramel and smoky. Both the type of oak chips and contact time could influence the aroma characteristics of the product. Specifically, sweet oak chips and dark chocolate oak chips mainly enhanced the smoky and caramel attributes, while contact with black spice oak chips and caramel oak chips further accentuated the fruity and whiskey-like notes. The flavor differences were more significant after 4 weeks of contact compared to 2 weeks. Samples in contact with black spice, dark chocolate, and special fruit oak chips developed a new "toasted bread" characteristic. This study provides a scientific basis and data support for the flavor regulation and quality improvement of strong ale.

Five tea plant accessions exhibiting varying purpling levels were selected to investigate the color parameters and metabolomic characteristics of fresh purple leaf tea leaves and their baked green tea infusions, using CIELAB colorimetry, ultra-high performance liquid chromatography-quadrupole-electrostatic field orbital trap mass spectrometry (UHPLC-Q-Exactive-MS), and photodiode array detector (PDA) detection, in order to elucidate the chemical basis of color differences in purple leaf tea. Results showed that, as purpling deepened, the L^* (lightness) and b^* (yellowness) values of both fresh tea leaves and baked green tea infusions significantly decreased, while a^* (redness) values generally increased. These changes were all highly correlated with anthocyanin content. Metabolomics identified a total of 122 compounds, and partial least squares-discriminant analysis (PLS-DA) effectively distinguished the tea samples. Analysis revealed that the color differences in purple leaf tea were not only determined by the total anthocyanin content, but were also closely related to the relative proportions of their core anthocyanin components. Specifically, the orange-red color of red purple (RP) infusions primarily originated from their abundance in cyanidin derivatives and higher content of theaflavins; Whereas the deep-purple hue of deep purple (DP) infusions was dominated by the highly abundant delphinidin derivatives. PDA spectral analysis confirmed that cyanidin-3-O-β-d-(6-(E)-p-coumaroyl) galactopyranoside and delphinidin-3-O-β-d-(6-(E)-p-coumaroyl) galactopyranoside were the major color contributors for RP and DP accessions, respectively. Furthermore, flavonol glycoside was key component forming the yellow base of green leaf (GL) infusions, and these, along with anthocyanins and tea pigments, synergistically constructed the color characteristics of the tea infusion through copigmentation effects. This study elucidated the intrinsic chemical compounds determining the color gradient and hue differentiation of purple leaf tea, which could provide a scientific basis for the quality evaluation of purple leaf tea.

To investigate the effects of storage duration on the flavor characteristics of Guizhou white tea, this study employed high-performance liquid chromatography, electronic nose detection, and gas chromatography-mass spectrometry (GC-MS) to analyze the major taste compounds and volatile components in Guizhou white tea from different storage years. The results revealed significant differences (P<0.05) in the contents of tea polyphenols, total flavonoids, caffeine, free amino acids, soluble sugars, lactic acid, L-malic acid, and catechin components during the aging process of white tea, whereas differences in water-extractable substances were relatively minor. Electronic nose analysis indicated that the aroma characteristics of Guizhou white tea from different vintages might be related to sulfides, aromatic components, and nitrogen‒oxygen volatile substances. Volatile compound analysis revealed 123 volatile substances across the different vintages of Guizhou white tea, including 17 alcohols, 13 aldehydes, 18 ketones, 23 alkanes, 12 alkenes, 22 esters, and 18 other compounds. Among these, 23 unique volatile compounds were detected in white tea from 2013, whereas only 1~3 unique volatile compounds were identified in tea from 2015, 2016, 2020, and 2022. Additionally, white tea produced in 2016 presented the highest total volatile content, while that from 2013 contained the most diverse array of volatile compounds. Odor activity value (OAV) analysis indicated that nonanal (OAV>20) significantly contributed to the formation of the characteristic aroma of white tea during storage. This study provides a theoretical basis for the scientific storage and quality enhancement of Guizhou white tea.

In order to investigate the key aroma compounds of Camellia sinensis var. assamica cv. Duntsa black tea and their formation mechanism during processing, this study utilized headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) to systematically analyze the volatiles in fresh leaves (XY), shaking (YQ), withering (WD), rolling (RN), fermentation (FJ), initial drying (CH), and finished product (CP). Principal component analysis (PCA) and orthogonal partial least squares-discrimination analysis (OPLS-DA) with permutation tests were performed. Key aroma compounds were identified using relative odor activity value (rOAV) and aroma character impact (ACI). Results revealed that during the processing, 107 volatile compounds were identified in the tea samples of Camellia sinensis var. assamica cv. Duntsa black tea primarily comprising alcohols, esters, and alkenes. During the whole processing process, the relative content of alcohols, esters and others showed a fluctuating downward trend. The relative content of aldehydes, ketones and olefins showed a fluctuating upward trend. The PCA and OPLS-DA models based on the relative content of aroma substances could effectively distinguish different processing samples. Further screening, with VIP>1, rOAV>1 and ACI>1% as the conditions determined that linalool, methyl salicylate, geraniol, hexyl hexanoate, trans-nerolidol and other five components together constituted the aroma quality of the sweet type of Camellia sinensis var. assamica cv. Duntsa black tea. The relative content of linalool, geraniol, and hexyl hexanoate showed an initial increase followed by a decline, peaking during the rolling stage at 382.74, 123.32, and 35.43 mg/L respectively. The relative content of trans-nerolidol showed a fluctuating upward trend, increasing by 22.60%. The relative content of methyl salicylate showed a fluctuating decrease, peaking at 252.95 mg/L during the rolling stage. The results of this study can provide a theoretical reference for the analysis of the aroma quality of Camellia sinensis var. assamica cv. Duntsa black tea.

This study aimed to investigate the quality characteristics and chemical composition of Baimudan white teas processed from different tea cultivars in the Yibin tea region, the quantitative descriptive analysis, biochemical analysis, high-performance liquid chromatography (HPLC), and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze the sensory quality and flavor compounds of white teas processed from eight cultivars, ‘Zhongcha 302’ (ZC302), ‘Fuding Dabaicha’ (FDDB), ‘Wuniuzao’ (WNZ), ‘Chuancha 2^#’ (CC2), ‘Fuxuan 9^#’ (FX9), ‘Mingshan 131’ (MS131), ‘Zhongcha 108’ (ZC108), and ‘Huangjinya’ (HJY). The results indicated that all eight tea varieties exhibited favorable sensory qualities, though significant differences existed among them. FDDB, ZC302, and CC2 presented a distinct tip aroma or floral fragrance, fresh and sweet taste, and soft, yellow-green infused leaves, achieving higher overall sensory scores. In contrast, WNZ and FX9 exhibited a clean and refreshing with noticeable grassy odour, along with approach fresh and mellow taste accompanied by grass or sour off-flavors, resulting in relatively lower sensory scores. HJY showed the highest free amino acid content and lowest phenol-ammonia ratio, yet it also had the lowest water extractives content. FDDB, ZC302, and CC2 displayed higher levels of free amino acids, theanine and sweet-tasting amino acids, while lower contents of tea polyphenols, total catechins, ester-type catechins, and bitterness-astringency index. Conversely, MS131 and FX9 had significantly higher levels of tea polyphenols, total catechins, ester-type catechins, and exhibited the highest bitterness-astringency index among all cultivars. Multivariate statistical analysis identified nine differential taste-related compounds, namely epigallocatechin gallate, caffeine, epigallocatechin, catechin, gallocatechin, tea polyphenols, theanine, water extractives, and epicatechin gallate. Furthermore, 28 key aroma compounds were identified in the three superior tea varieties. Among these, linalool, geraniol, and phenylacetaldehyde were more abundant in CC2, contributing to its prominent floral aroma, while green-note compounds such as (Z)-3-hexenol and hexanal occurred at relatively lower levels in FDDB and ZC302. In conclusion, tea varieties significantly influenced the quality characteristics of white tea. FDDB, ZC302, and CC2 demonstrated superior suitability for white tea production, providing a scientific basis for tea varieties selection and quality enhancement of Yibin white tea.

This study aimed to mitigate the quality deterioration of highland barley leavened pancakes during frozen storage at −18 ℃. The effects of incorporating soluble soybean polysaccharide (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, based on dry flour weight), sodium alginate (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, based on dry flour weight), and xanthan gum (0%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, based on dry flour weight) on the texture, specific volume, frying loss, and water migration of the pancakes were systematically evaluated. Results demonstrated that all three polysaccharides improved the textural properties by significantly reducing hardness, gumminess, and chewiness, while enhancing resilience and springiness, effectively inhibiting quality deterioration. 0.5% Xanthan gum exhibited the most pronounced effect. It significantly increased gas retention capacity, leading to a 53% higher specific volume and a 27.23% reduction in frying loss after three freeze-thaw cycles. After 30 days of frozen storage, the specific volume remained 30.67% higher than that of the control. Low-field NMR analysis revealed that during frozen storage, the 0.5% xanthan gum group exhibited no significant changes in the relaxation times of T₂₁ and T₂₂ peaks, while the T₂₃ peak shifted slightly to the left. Furthermore, the area proportion of the T₂₁ peak in this group was significantly higher than that in other groups, indicating reduced water mobility and enhanced water-holding capacity. Additionally, this group maintained a high sensory score even after 30 days of frozen storage. In conclusion, 0.5% xanthan gum demonstrated the optimal comprehensive performance in improving the specific volume, textural stability, water-holding capacity, and sensory quality of hulless barley leavened pancakes, and thus could serve as a preferred modifier to enhance the frozen storage quality of hulless barley leavened pancakes.

To investigate the effects of light exposure on the storage quality of Phyllanthus emblica L. preserved fruit and to establish a shelf-life prediction model, this study subjected two varieties, 'Huafeng' (HF) and 'Wild' (YS), packaged in transparent (TM) and light-blocking (BG) packaging bags were used as research objects. Accelerated storage experiments were carried out for 25 days at 25 ℃ and 2000 lux light conditions. Monitor 18 indicators changes, including color, texture, chemical composition, antioxidant activity, and sensory dynamically. Pearson correlation analysis and chemical kinetic modeling were integrated to construct a shelf-life prediction model, enabling the estimation of product stability based on critical quality attributes. The results demonstrated that light exposure significantly accelerated quality deterioration. Notably, the L^* value, b^* value, hardness, elasticity, chewiness, moisture content, total acid, total sugar, reducing sugar, ascorbic acid, total phenols, flavonoids, antioxidant activity, and overall sensory score decreased significantly (P<0.05), whereas the a^* value, ΔE value, and cohesiveness increased (P<0.05). Light-blocking (BG) packaging effectively delayed this deterioration. On day 25, the overall sensory scores ranked as follows: BG-YS>BG-HF>TM-YS>TM-HF. Pearson correlation analysis identified L^* value, elasticity, and ascorbic acid content as the indicators most strongly correlated with sensory score. These were selected as key predictors, and their degradation followed zero-order kinetics. The established shelf-life prediction model showed a relative deviation between predicted and actual values of less than 10%, confirming its accuracy and reliability for the rapid assessment of the product's shelf life.

This study explored the preservative effect and shelf-life extension of chilled mutton by coating with a mustard essential oil-based Pickering emulsion. It also provided data to support the practical application of such emulsions in meat preservation. The experiment involved applying a mustard essential oil Pickering emulsion as a surface coating on chilled mutton, and the study assessed the emulsion's antioxidant activity, antibacterial performance, and impact on mutton quality indicators. Results indicated that increasing the concentration of mustard essential oil significantly enhanced the emulsion's antibacterial effect (P<0.05), with varying inhibitory effects on different bacteria at the same concentration. At a 2.0% v/v concentration, the Pickering emulsion exhibited good antioxidant and antibacterial properties. The inhibition zones for four pathogenic bacteria measured 20.20±0.11, 19.07±0.06, 12.13±0.06, and 10.73±0.06 mm, respectively. The DPPH, ABTS⁺, and OH radical scavenging activities were 89.45%, 66.61%, and 94.5%, respectively. Regarding preservation, indicators such as pH, meat color, TVB-N content, TBARs value, carbonyl and thiol content, total bacterial count, and coliform count in the soaking and spraying groups were significantly better than those in the control group (P<0.05). Notably, the pH in both groups remained within the fresh meat range on the 28th day of storage. The TBARs value remained within the acceptable range within 21 days, and the carbonyl content during storage was significantly lower than that in the control group (P<0.05). The control group samples began to deteriorate by the 7th day, while the soaking and spraying groups extended the storage period to 14 and 21 days, respectively. In conclusion, the mustard essential oil Pickering emulsion effectively improves the preservation of chilled mutton and extends its shelf life, with the 2.0% v/v concentration offering optimal antioxidant and antibacterial performance. The soaking treatment outperformed the spraying method, showing potential for broader application in meat product preservation.