To address consumer demand for nutritious and functional foods, and to promote the diversification of dairy products as well as the high-value utilization of jujube and selenium-rich resources, this study developed jujube-flavored selenium-enriched yogurt melts by first preparing a selenium-enriched yogurt base using a composite starter culture consisting of selenium-enriched Lactobacillus rhamnosus, Lactobacillus bulgaricus, and Streptococcus thermophilus, followed by the incorporation of jujube powder. The process parameters were optimized via single-factor and response surface methodology (RSM) experiments, with sensory evaluation as the key indicator. The optimal conditions were: 0.5 g jujube powder addition, and pre-frozen at −45 ℃, then freeze-drying at 38 ℃. Under these conditions, the product achieved a sensory score of 87.38, with dietary fiber content of 0.32%, total selenium content of 19.27 μg/100 g, vitamin C content of 1.85 mg/100 g, and total antioxidant capacity (FRAP value) of 14.17 mmol/L. Compared to ordinary samples, the developed product exhibited higher levels of selenium, vitamin C, and dietary fiber, and better sensory and texture characteristics. Scanning electron microscopy and secondary structure analysis revealed a denser and more continuous microstructure, with an increased proportion of β-sheet conformations, confirming improved protein structural stability. In addition, the product showed clearly improved instant solubility and antioxidant activity. In summary, this study provides a novel approach for functional dairy product development and resource utilization.

To improve the quality of processed blue honeysuckle (Lonicera caerulea L.) products, this study employed a mixed starter culture of lactic acid bacteria (Lactobacillus acidophilus, Lactobacillus fermentum, and Lacticaseibacillus rhamnosus) in combination with eggshell powder for co-fermentation to produce calcium-enriched fermented blue honeysuckle juice. An unfermented group, a single lactic acid bacteria fermentation group, and co-fermentation groups with lactic acid bacteria and eggshell powder (at addition levels of 0.5% and 1%) were established to systematically evaluate juice yield, soluble solids contents, sensory quality, calcium contents, polyphenol and anthocyanin contents, as well as the composition of non-volatile metabolites. The results showed that lactic acid bacteria fermentation increased the soluble solids contents of the juice, reduced bitterness and astringency, and promoted the accumulation of total phenolics and anthocyanins. Co-fermentation with eggshell powder effectively increased the bioavailable calcium contents of the juice and promoted the conversion of calcium carbonate into readily absorbable calcium chelates. Among them, the 1% eggshell powder group exhibited total calcium, organic acid-bound calcium, and protein-bound calcium contents of 2229.73, 1681.44, and 537.90 mg/L, respectively. A total of 732 metabolites were identified by liquid chromatography–mass spectrometry. Lactic acid bacteria fermentation effectively promoted the enrichment of functional components such as flavonoids, phenolic acids, terpenoids, glycosides, alkaloids, and amino acid derivatives, with the co-fermentation groups supplemented with eggshell powder showing the most pronounced effects. In conclusion, the synergistic fermentation of lactic acid bacteria and eggshell powder significantly improved the flavor and nutritional quality of blue honeysuckle juice, providing a new strategy for the development of calcium-enriched functional beverages and the high-value utilization of blue honeysuckle resources.

To address the problem of the sour and astringent taste of Rosa roxburghii Tratt. juice, in this study, we mixed fresh R. roxburghii juice with fresh apple juice, and then used Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus fermentum, respectively, as starters for fermentation. Following fermentation, the physicochemical indices, in vitro antioxidant indices, organic acid contents, and volatile components of the fermented juices in each experimental group were determined, with the unfermented mixed juice being used as the control. The results of physicochemical analyses revealed that the total acid and tannic acid contents in the R. roxburghii–apple mixed juice fermented using L. paracasei were 3.61 g/L and 0.059 mg/mL, respectively, which were significantly lower than the respective values obtained for other experimental groups and the control group (P<0.05). For the L. paracasei fermentation, the contents of vitamin C and carotenoids were 2.75 mg/100 mL and 572.28 μg/mL, respectively, which were significantly higher than those recorded for the other experimental groups (P<0.05). In addition, the results of in vitro antioxidant assays revealed that fermentation with all three lactic acid bacterial strains promoted an enhancement of the antioxidant capacity of the mixed juice, among which, all assessed antioxidant indices of the L. paracasei-fermented juice were superior to the corresponding values obtained for the control group and other experimental groups. Moreover, the results of organic acid analyses indicated that among all groups, the L. paracasei group had the lowest malic acid content and highest lactic acid content, making it most conducive to improving the composition of organic acids in the mixed juice. The results of volatile component analyses indicated that fermentation with L. paracasei was most beneficial for retaining the key flavors of R. roxburghii and apple. In conclusion, among the assessed bacterial strains, using L. paracasei as a starter was found to be more beneficial for ameliorating the sour and astringent taste of the R. roxburghii–apple mixed juice, enhancing the antioxidant capacity of the juice, and retaining the key aroma substances.

This study aimed to establish a novel and efficient analytical method based on magnetic expanded graphite (MEG) solid-phase extraction coupled with gas chromatography-mass spectrometry to address the challenge of accurately determining the trace characteristics of the aroma compound 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) in Riesling wines. The MEG adsorbent was prepared via a facile physical blending method, and its physicochemical properties were systematically characterized. Additionally, the key parameters affecting the magnetic solid-phase extraction (MSPE) pretreatment were optimized. Furthermore, density functional theory calculations were employed to investigate the adsorption mechanism at the molecular level. The results indicated that the method exhibited good linearity in the range of 0.05~100 ng/mL (R²=0.9943), with a limit of detection as low as 0.01 ng/mL. Theoretical calculations confirmed that the synergistic effect of van der Waals forces and π–π stacking (binding energy: −0.84 eV) was the key driving force for the efficient adsorption of TDN. The proposed method was successfully applied to the analysis of various Riesling wine samples, demonstrating high efficiency, accuracy, and reliability in the quantitative analysis of the target compound. This study not only provides a rapid and sensitive analytical tool for TDN but also offers new insights guided by theoretical calculations for the design and application of novel enrichment materials for food flavor compounds.

Different medicinal herbs play an important role in shaping the characteristic flavor of traditional herbal chicken soup. In this study, chicken soup prepared with Radix Astragali (HQ), Radix Codonopsis (DS), Fructus Lycii (GQ), and Fructus Jujubae (HZ) was used as the control (CK). Four model soups were established by individually omitting one of these herbs: -HQ, -DS, -GQ, and -HZ. The characteristic flavors and their sources were compared using intelligent sensory techniques, gas chromatography–mass spectrometry (GC–MS), free amino acid analysis, flavor nucleotide analysis, and orthogonal partial least squares-discriminant analysis (OPLS-DA). The results showed that the electronic nose and electronic tongue could effectively detect and distinguish differences in odor and taste among the five groups. The omission of herbs mainly led to a decrease in the response values of the hydrogen sulfide-sensitive sensor (W1W) and the umami sensor (NMS). Further analysis revealed that the omission of herbs led to a reduction in the total content of volatile flavor compounds. OPLS-DA and variable importance in projection (VIP) analysis identified ten volatile flavor compounds as the main contributors to the overall flavor profile, including 2,3-butanedione, 1-hexanol, dipentene, hexanal, 2-methylbutanal, and phytol. Compared to the other omission groups, the -HQ group showed the greatest distance from both these key compounds and the electronic nose sensor signals, indicating that Radix Astragali has the most significant impact on the overall flavor of the chicken soup. Additionally, the levels of key umami compounds (Glu and 5’-IMP) were reduced in the herb-omitted groups. In conclusion, the absence of any herb affects the characteristic flavor of the soup, with Radix Astragali contributing the most notably to its distinctive flavor profile.

To investigate the correlation between growing environment and stable isotopes and mineral elements in 80 Yunnan large-leaf sun-dried green tea samples (from 4 production areas: Ning'er County, Lianghe County, Simao District and Jinghong City, Yunnan Province), 24 trace elements, 14 rare earth elements and 5 stable isotopes were analyzed and determined by using Elemental Analyzer-Isotope Ratio Mass Spectrometry (EA-IRMS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). To explore the feasibility of discriminating large-leaf sun-dried green tea from different geographical origins, multiple multivariate statistical methods were employed, including analysis of variance (ANOVA), principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and linear discriminant analysis (LDA). Tea from Lianghe County recorded a significantly higher total mineral element content compared to the other three regions (P<0.05). PCA extracted seven principal components with a total cumulative variance contribution rate of 80.831%. An OPLS-DA model provided effective differentiation of samples from the 4 different regions, from which 15 key variables with variable importance in projection (VIP) scores >1 were screened (δ²H, δ¹⁸O, Rb, Al, Tl, Cs, δ³⁴S, Mn, Cu, Cd, Ga, Ba, Fe, As, Sr). Subsequently, these markers were subjected to Fisher's LDA. This model achieved 100.0% correct discrimination and a 92.5% cross-validation rate, demonstrating its robust capability for origin traceability of Yunnan large-leaf sun-dried green tea. This study demonstrated the feasibility of tracing the geographical origin of Yunnan large-leaf sun-dried green tea through mineral element and stable isotope analysis. The findings provided a research foundation for origin discrimination at a more accurate geographical scale and for the protection of geographical indication products in Yunnan.

To screen for whole sweet potato powder (WSP) suitable for various industrial production processes, this study employed two representative sweet potato cultivars (Lingzi and Hong'anhong) as raw materials. It compared the variations in physicochemical properties, functional characteristics, sensory quality, and other related traits among four types of WSP produced by distinct processing methods: raw WSP, cooked WSP, freeze-dried WSP, and fermented raw WSP. The results showed that the pH of raw, cooked, and freeze-dried WSP ranged from 6.31 to 6.52, whereas fermentation decreased the pH of raw WSP to 4.42~5.90. Notably, single-strain fermentation using Lactiplantibacillus plantarum exhibited the strongest acid-producing capacity, with a total titratable acidity (TTA) value approximately three fold higher than that of unfermented raw WSP. Cooked WSP exhibited no endothermic peak, attributed to complete gelatinization. Among WSP samples of the same cultivar, cooked WSP had significantly higher water-holding capacity and water absorption-swelling capacity but poor freeze-thaw stability. Regarding oil-holding capacity, raw WSP was the lowest, whereas fermentation increased this capacity to more than twice its initial level. Furthermore, raw WSP fermented with single-strain L. plantarum had the highest soluble sugar content. Freeze-dried WSP performed best in sensory evaluation, with a total sensory score 7.56%~22.54% higher than those of the other types. For purple WSP, the anthocyanin content in freeze-dried purple WSP was approximately 5.32 times that in raw purple WSP. This study provides a valuable reference for the quality control, industrial-scale production, and application expansion of WSP.

This study investigates how a processing technique designed to improve sensory quality affects flavor attributes and the relative concentrations of volatile and non-volatile compounds in Sichuan Gongfu black tea. The tea cultivar "Zhongcha 302" was used in the experiments. The impact of the processing technique on the aroma and taste qualities of Sichuan Gongfu black tea was evaluated by quantitative descriptive analysis, ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS/MS), and gas chromatography-mass spectrometry (GC-MS), combined with correlation analysis. The results showed that processing increased the sweet, floral, and fruity aromas, as well as the sweet and umami attributes of Sichuan Gongfu black tea. GC-MS analysis identified 34 key volatile compounds with odor activity values greater than 1, including geraniol, (E)-2-decenal, phenylacetaldehyde, nonanal, (E)-2-nonenal, o-cymene, (Z)-6-nonenal, (Z)-2-decenal, α-phellandrene, 2-pentylfuran, and heptanal. UPLC-MS/MS-based metabolomics identified 74 non-volatile compounds influenced by processing, including rutin, luteolin 7-xyloside, epicatechin gallate, p-coumaric acid, feruloyl-L-glutamic acid, and L-theanine. Tea processing altered the relative concentrations of several compounds, particularly flavonoids and phenolic acids, as well as amino acids (and their derivatives). Pearson correlation analysis showed that o-cymene, geraniol, phenylacetaldehyde, heptanal, p-cymene, trans-linalool oxide (furanoid), linalool, (E)-2-octenal, and α-ionone were associated with higher sensory scores for the floral, fruity, and sweet aroma attributes in the processed tea. The increased concentrations of L-glutamic acid, L-proline, and L-theanine were associated with greater umami and sweetness. In contrast, tea processing decreased the relative concentrations of luteolin 7-xyloside, epicatechin, p-coumaric acid, ferulic acid, theobromine, and proanthocyanidins, which might explain the reduced bitterness and astringency. These findings provide a theoretical basis and technical guidance for improving the quality of Gongfu black tea.

This study focused on dried sweet potatoes to develop a suitable sensory flavor evaluation method, where a sensory panel performed quantitative descriptive analysis on 41 commercial samples. The descriptive words were selected and summarized, a dried sweet potatoes gratin flavor wheel was constructed, and sensory evaluation tools were designed. A total of 67 descriptor words were obtained, and constructed a flavor wheel covering taste, odor, texture, and appearance. Using the geometric mean method combined with cluster analysis and principal component analysis, 29 characteristic descriptors were screened, including 5 for appearance, 6 for odor, 9 for taste and 9 for texture. The analytic hierarchy process determined the sensory indicator weight ratio as taste:texture:odor:appearance=40:35:10:15. Subsequently, two methods were established, including a suitability-based one for ordinary consumers and a quantitative descriptive one for professional evaluators. This study could provide a reference for the quality evaluation and product development of dried sweet potatoes.

To investigate the effects of Codonopsis pilosula and Astragalus membranaceus on the quality of stewed chicken, the chicken leg meat was used as the raw material, and the impact of different addition ratios of these two herbal ingredients on the physicochemical properties, sensory attributes, active ingredient, taste compounds, and volatile aroma profiles was systematically examined. The results demonstrated that the L^* values in the Codonopsis pilosula and Astragalus membranaceus treatment groups were lower than those in the control (CON) group. The shear force in the DSHQ-1 group was significantly reduced compared to the CON group (P<0.05), suggesting improved tenderness; however, further increasing the proportion of Codonopsis pilosula led to an increase in shear force. Notably, the moisture content, flavonoid and polysaccharide levels, as well as sensory evaluation scores, were all higher in the treatment groups than in the control, indicating that the incorporation of these herbs promoted the retention of functional components and enhanced both palatability and overall sensory quality. With regard to flavor characteristics, the total amino acid content in the DSHQ-5 group was significantly higher than that in the CON group (P<0.05), reflecting a pronounced flavor-enhancing effect. A total of 45 volatile aroma compounds were identified by GC-MS analysis, comprising 10 aldehydes, 5 esters, 2 acids, 8 alcohols, 9 hydrocarbons, 5 ketones, 3 terpenes, and 3 other compounds. Overall, the concentration of aromatic substances in the stewed chicken from the DSHQ-2, DSHQ-3, DSHQ-4, and DSHQ-5 groups was higher than that in the CON group. The addition of Codonopsis pilosula and Astragalus membranaceus enriched the terpene content in the stewed chicken, thereby effectively enhancing its flavor complexity. Furthermore, 12 characteristic volatile aroma compounds with OAV>1 were identified through odor activity value (OAV) analysis. Among these, hexanal, eucalyptol, and 1-octen-3-ol exhibited the highest OAVs, contributing oily, herbal, and mushroom-like aromas, respectively. In conclusion, Codonopsis pilosula and Astragalus membranaceus improve the overall quality of stewed chicken and enhance its flavor profile. Their combined use demonstrates practical potential for application in chicken-based food processing.