Using polysaccharide extraction yield as the indicator, this study investigated the effects of hot water extraction (HWE), enzyme-assisted extraction (EAE), and semi-bionic extraction (SBE) on the extraction yield of Prunella vulgaris L. polysaccharides. The extraction method with the highest polysaccharide yield was selected for process optimization. The structure of the polysaccharides was characterized using high-performance liquid chromatography, gel permeation chromatography, ultraviolet spectroscopy, and Fourier-transform infrared spectroscopy. In addition, the in vitro antioxidant and enzyme inhibitory activities were evaluated. The results showed that the polysaccharide yields obtained by the HWE, EAE, and SBE were 5.9%, 7.54%, and 9.87%, respectively. After optimization, the best extraction conditions for the SBE method were determined as follows: extraction temperature of 85 ℃, duration of 2.5 h, simulated gastric fluid (pH2.0) and intestinal fluid (pH8.5), and a solid-to-liquid ratio of 1:30. Under these conditions, the polysaccharide yield reached 11.69%. Structural analysis revealed that Prunella vulgaris polysaccharides were mainly composed of rhamnose, galacturonic acid, glucose, galactose, xylose, and arabinose, the molar ratios were 8.89, 41.81, 17.53, 6.85, 14.32 and 7.21, respectively. Antioxidant activity tests showed that the IC₅₀ values for scavenging DPPH·, ABTS⁺·, ·OH and O₂⁻· were 0.049, 0.092, 0.085 and 0.062 mg/mL, respectively, while the maximum total reducing power was measured at 0.314 when the polysaccharide concentration was 1.1 mg/mL. The polysaccharide also exhibited inhibitory effects on α-glucosidase and α-amylase, with IC₅₀ values of 1.72 and 8.43 mg/mL, respectively. This study systematically optimized the extraction process of P. vulgaris L. polysaccharides, preliminarily clarified their structural characteristics, and confirmed their strong antioxidant activity. These findings provide theoretical basis and technical support for the further development and application of P. vulgaris L. polysaccharides.

In the present work, Eurotium cristatum fermentation was applicated in Penthorum chinense Pursh (PCP) leaf tea production, to reduce the bitterness, astringent tastes and pronounced herbaceous flavor of PCP leaves. Based on the results of single-factor experiments and response surface methodology (RSM) according to sensory evaluation, the optimal fermentation conditions were determined as follows: water contents 27%, incubation amount 21%, with 16 days of incubation time. The E. cristatum fermented PCP leaf tea produced in the optimal condition had orange-yellow infusion appearance with abundant E. cristatum colonization, tasting smooth and mellow with harmonious aroma, which achieved the sensory score at 91.60, while the total polyphenols and total flavonoids contents were reduced by 16.95% and 18.70%, respectively. Compared with the unfermented samples, the ratio of bitter and sweet amino acids of fermented PCP leaf tea decreased by 7.16%. The results of HS-SPME-GC-MS showed that the undesirable volatile components (VOCs), including hexanal, trans-2-hexenal, (E,E)-2,4-heptadienal, and 6-methyl-5-hepten-2-one representing grassy, pungent, and irritating odors, remarkably decreased, and the VOCs associated with floral, fruity, and fungal aromas, including acetophenone, linalool, and 2-butanone were newly generated and increased in PCP leave tea after fermentation. In summary, the optimal E. cristatum fermentation was confirmed to significantly improve the sensory quality of PCP leaf tea, especially eliminating the undesirable flavors and tastes, which could be a promising technology applicated in PCP tea process.

To address the high glycemic index (GI) and monotonous flavor of traditional rice cakes, in this study, a low-GI large-leaf yellow tea rice cake was developed using indica rice flour, glutinous rice flour, and large-leaf yellow tea powder, substituting traditional white sugar with erythritol. Single-factor experiments and orthogonal testing optimization identified an optimal formula consisting of an indica rice flour to glutinous rice flour ratio of 5:2, with the addition of 3% large-leaf yellow tea powder, and 3% erythritol content. The optimal formula achieved a comprehensive score of 84.67. The analysis results of flavor characteristics revealed enhanced umami and complexity in large-leaf yellow tea rice cakes, with significantly higher contents of 74 aromatic components (including benzaldehyde), forming a distinctive mellow tea aroma profile. Radical-scavenging assays demonstrated that large-leaf yellow tea powder significantly improved the clearance rates of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radicals. In vitro digestion experiments revealed an elevated resistant starch content (68.03%±4.61%) and a lower amount of rapidly digestible starch content (12.58%±2.89%) in large-leaf yellow tea rice cakes, resulting in an estimated glycemic index of 57.56, 11.97% lower than that of the control group, almost meeting the criteria for low-GI foods. This study pioneers the application of large-leaf yellow tea powder in the development of low-GI rice products, providing a theoretical foundation and technical references that is expected to drive innovation in the development of functional traditional food.

This study investigated the co-fermentation of shrimp shells/heads and soybean substrates using a Mucor, Rhizopus oryzae, and Aspergillus oryzae mixed culture system. The microbial ratio was optimized through orthogonal experiments, with amino nitrogen content and sensory attributes serving as key assessment criteria. The optimal fermentation conditions were further validated by volatile flavor analysis. Additionally, the quality of laboratory-produced shrimp paste was compared with commercial products based on color parameters, total volatile basic nitrogen, pH, and free amino acid composition. The result showed that an optimal inoculum ratio of 3:1:3 (Mucor:Rhizopus oryzae:Aspergillus oryzae) yielded shrimp paste with 1.19 g/100 g amino nitrogen and a 92.53-point sensory score. Key aromatic compounds, including pentanal (monomer/dimer), hexanal, 3-pentanone, 3,5,5-trimethyl-2-cyclohexen-1-one, and ethyl acetate, demonstrated superior relative odor activity values. Compared with them to commercial counterparts, our formulation exhibited enhanced color parameters (a^*=12.26, b^*=19.91), lower total volatile basic nitrogen (117.98 mg/100 g), a higher proportion of umami amino acids (20.78% of total amino acids), and a lower proportion of bitter amino acids (42.77% of total amino acids). Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy analyses confirmed that the proteins in the shrimp byproducts were fully utilized during fermentation, with the remaining insoluble fractions exhibiting the characteristic functional groups, crystalline structure, and microscopic morphology of α-chitin. The findings of this study demonstrate that mixed-strain fermentation enhances flavor characteristics while reducing the accumulation of undesirable metabolites, providing both a theoretical foundation and technical support for the value-added utilization of shrimp by-products and industrial-scale production of premium shrimp paste.

To enhance the drying efficiency and quality of vacuum pulsation-dried chili peppers and to obtain the optimal pretreatment method, this study used ultrasonic, ultrasonic combined with blanching, and ultrasonic combined with freeze-thawing for the pre-drying pretreatment of chili peppers and analyzed the drying characteristics, physicochemical properties, and volatile composition of vacuum pulsation-dried chili peppers. The results showed that all the pretreatments effectively shortened the drying time, reduced the energy consumption of vacuum pulsation drying of chili peppers, and improved the physicochemical quality and flavor of the samples, and the ultrasonic combined with blanching had the best effect. Compared with the control samples, ultrasonic combined with blanching samples shortened the drying time by 29.15%, reduced energy consumption ration by 39.19%, retained capsorubin reached 100%, increased the contents of capsaicin, dihydrocapsaicin, vitamin C, and total phenols by 28.68%, 31.46%, 10.10%, and 68.90%, respectively, increased DPPH radical scavenging capacity and total antioxidant capacity by 14.11% and 70.45%, respectively, and had the best physical properties improvement and volatile substances retention; by microstructure and low-field nuclear magnetic resonance analysis revealed that the breakage of cellular tissue structure by pretreatment was the main reason for the shortening of drying time, the reduction of energy consumption and the improvement of quality. Pearson correlation analysis showed that volatiles such as aldehydes and esters were positively correlated with the a^* value, vitamin C content, and capsanthin content, whereas nonanal exhibited a negative correlation with capsaicin and dihydrocapsaicin content. This study provides theoretical and technical support for reducing the energy consumption and improving the quality of chili pepper drying.

In order to solve the problem of the thin flavor of Yunnan sweet rice wine. This study had focused on locally screened high alcohol producing Saccharomyces cerevisiae LF05 and high esters producing Rhodotorula mucilaginosa PL10, investigating the effects of their mono- and co-fermentation with Rhizopus oryzae on the physicochemical properties, sensory characteristics, free amino acids, and volatile compounds of the wine. The synergistic fermentation with yeasts and Rhizopus oryzae had significantly enhanced ethanol concentration, umami amino acids, sweetness amino acids, and volatile compound content in sweet rice wines. The LF05-PL10 co-culture group had demonstrated the highest sensory score, umami amino acids, sweetness amino acids, higher alcohols, and ester compounds among all experimental groups, with increases of 89.03%, 94.07%, 155.37%, 335.04%, and 412.25% compared to the Rhizopus oryzae-only group, respectively. This synergistic effect had achieved the goal of “enhancing alcohol content, ester synthesis, and aroma complexity” in the fermented product. Orthogonal partial least squares-discriminant analysis (OPLS-DA) had been applied to 16 free amino acids and 73 volatile compounds in sweet rice wines. With variable importance in projection (VIP) values ≥1 as the threshold, 8 differential amino acids and 30 differential volatile metabolites had been identified as key contributors to the characteristic flavor profile of the wine. In conclusion, the cooperative fermentation strategy using Saccharomyces cerevisiae/Rhodotorula mucilaginosa with Rhizopus oryzae had effectively alleviated the bland flavor issue in Yunnan sweet rice wines, providing a theoretical foundation for flavor quality optimization in traditional fermented beverages.

In order to explore the differences in volatile organic compounds (VOCs) among six different formulations of five-spice seasoning oils, electronic nose, headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS) were used in this study. The electronic nose sensor had a strong response to alkanes, alcohols, ketones and aldehydes in VOCs, and PF6 had a strong flavor response. HS-SPME-GC-MS identified 118 VOCs in the six formulations, including olefins, esters, ketones, alcohols, alkanes, aldehydes, acids, phenols, ethers, and heterocyclic compounds. Anise-based PF1 had 31 VOCs, PF3 had 33, PF5 had 37, and PF6 had 46; Cinnamon-based PF2 had 47; Galangal-based PF4 had 32. Relative odor activity value (ROAV) analysis found 14 key VOCs, with anisaldehyde, artemisia ketone, and eucalyptol (responsible for anise and camphor-like aromas) being the major contributors. A total of 45 VOCs were identified by GC-IMS, through principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), 19 key VOCs differentiating the formulations were found, such as phenethyl alcohol, 2-methyl-2-propanol, ethyl hexanoate, oxylinalool, 1-octanol, and 1-penten-3-one. This study is helpful to provide a basis for the study of complex flavor system, and provide a reference for the development of spice products.

The aim of this study was to explore the effect of steam-roasting treatment on the eating quality and flavor of Gamba (French-style) lamb chops. Gamba (French-style) lamb chop was selected as the research subject. The steam-roasting oven was used to steam-roasting and traditional roasting process on Gamba (French-style) lamb chops. Their color, texture, water-holding capacity, and cooking loss were measured and analyzed. The moisture distribution, myofibrillar structure, and volatile flavor compounds of all different treatment groups were detected using low-field nuclear magnetic resonance (LF-NMR), scanning electron microscopy (SEM), and gas chromatography-ion mobility spectrometry (GC-IMS). Sensory evaluation was performed to assess the eating quality of Gamba (French-style) lamb chops with different treatments. The results showed that during steam-roasting treatment, the surface a^* value of ZK10 was significantly higher than that of KZ10 (P<0.05). The surface b^* value of ZK5 was significantly lower than that of KZ5 (P<0.05). The ZK5 Gamba (French-style) lamb chops exhibited lower shear force (55.25±1.10 N), chewiness (3.25±0.46 mJ), hardness (1.59±0.14 N), cooking weight loss rate (18.56%), and TBARS value (8.47 mg/kg), while maintaining higher water-holding capacity (79.22%), moisture content (58.7%), and elasticity (8.96±0.49 mm). Additionally, the myofibrillar structure was less damaged. Sensory evaluation indicated that ZK7 achieved the highest scores in color, appearance, taste, and overall acceptability, while ZK5 excelled in terms of taste. GC-IMS fingerprinting revealed 53 volatile compounds in the lamb chops, including aldehydes, ketones, alcohols, heterocyclic compounds, and alkanes. The ZK groups produced the highest diversity of volatile components, primarily alcohols and aldehydes. Their characteristic flavor compounds mainly including 1-butanol-M, 1-hexanol-D, 1-pentanol-D, 1-penten-3-ol, 2-methylbutyraldehyde-M, 1-propanol-D, 3-hydroxy-2-butanone-M, acetic acid-M, (E)-2-heptenal, (E)-2-hexenal, 1-butanol-D, butyraldehyde-M, 1-nonanal-M, heptanal, 1-hexanal-D, ethyl heptanoate, acetic acid-D, 1-nonanal-D, 1-octenal-M, 2-methyl-2-hepten-6-one, 1-octenal-D, butyraldehyde-D, 3-hydroxy-2-butanone-D, 2-methylbutyraldehyde-D, and α-pine. The steam-roasting treatment can enhance the brightness, yellowness, elasticity, water-holding capacity, and moisture content of Gamba (French-style) lamb chops, reduce hardness, shear force, chewiness, and cooking loss rate, effectively inhibit lipid peroxidation, partially protect the myofibrillar structure, and promote the formation of more volatile substances, particularly alcohols and aldehydes.

As a crucial fermenting and saccharifying agent for Fen-flavor Baijiu, low-temperature Daqu provides abundant microorganisms, enzyme systems, and flavor precursor substances during the brewing process, influencing the liquor's style and yield. To investigate the quality differences of low-temperature Daqu from different regions, this study employed PacBio SMRT sequencing, electronic nose, electronic tongue, and physicochemical analysis to conduct a comprehensive analysis of low-temperature Daqu samples collected from Xiangyang and Fenyang City. Results revealed that there were significant differences in microbial community diversity and structure between the two regions (P<0.05). Specifically, species such as Lactiplantibacillus plantarum and Saccharomycopsis fibuligera were significantly enriched in the Xiangyang low-temperature Daqu samples (P<0.05), while species such as Bacillus licheniformis and Issatchenkia orientalis were significantly enriched in the Fenyang low-temperature Daqu samples (P<0.05). Xiangyang low-temperature Daqu was rich in aromatic compounds with a more prominent richness (P<0.05), while Fenyang low-temperature Daqu contained higher concentrations of alcohols and aldehydes/ketones, with more prominent sourness, bitterness, and astringency (P<0.05). Xiangyang low-temperature Daqu samples had significantly higher water activity, bound water content, liquefying power, acidity, ash content, and starch content (P<0.05), while Fenyang low-temperature Daqu samples had significantly higher Qu-skin hardness, Qu-core hardness, water content, immobilized water content, liquor-producing power, fermentation power, esterifying power, saccharification power, and protein content (P<0.05). There was a significant correlation between the dominant species in Daqu and sensory and physicochemical indicators. It could be seen that there were significant differences in microbial community structure and quality indicators between Fenyang and Xiangyang low-temperature Daqu. These findings provide empirical data support for improving the quality of Fen-flavor Baijiu.

This study established an integrated analytical strategy combining elemental profiling via inductively coupled plasma mass spectrometry (ICP-MS) and spectral fingerprinting via Fourier transform infrared spectroscopy (FTIR) to discriminate geographical origins of Larimichthys crocea (L. crocea) from five coastal Chinese cities: Zhoushan, Taizhou, Wenzhou, Ningde, and Zhanjiang. Significant inter-origin variations (P<0.05) were observed in the mass fractions of 13 key elements: aluminium (Al), titanium (Ti), chromium (Cr), manganese (Mn), arsenic (As), selenium (Se), strontium (Sr), barium (Ba), mercury (Hg), lead (Pb), iron (Fe), nickel (Ni), and tin (Sn). Region-specific elemental signatures were identified: Taizhou samples demonstrated maximal Al, Se, and Hg content with minimal As levels; Zhoushan samples contained peak Ni concentrations; Wenzhou samples exhibited significantly elevated Ti, Cr, Mn, and Sr alongside minimal Se; whereas Zhanjiang samples showed maximal As levels with suppressed Al, Ti, Cr, Mn, Fe, Ni, Ba, and Pb. Multivariate chemometric analysis of the integrated ICP-MS/FTIR dataset, incorporating principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA), achieved precise discrimination among the five geographical origins. PCA revealed five distinct, non-overlapping clusters in the score plot (PC1/PC2 cumulative variance=74.7%). CA further confirmed independent clustering by origin. The LDA model achieved 100% accuracy in re-substitution validation and 97.3% in cross-validation. This work demonstrates that ICP-MS/FTIR integration augmented by chemometrics establishes a rapid, highly accurate platform for authenticating L. crocea geographical origin, providing a robust framework for safeguarding aquatic geographical indications.