| American ginseng is the root of Panax quinquefolium L.,which belongs to the genus Panax ginseng.It undergoes traditional origin processing predominantly through sun drying and heat drying.These methods are fraught with challenges such as prolonged drying periods,high energy consumption,and unmanageable quality,culminating in the degradation of sample quality,diminution of nutritional value,and squandering of resources.Presently,the processing techniques for American ginseng are monolithic and bereft of a rigorous quality control framework.Functional studies have been narrowly focused on the pharmacological effects of compounds and the prevalent major ginsenoside monomer substances,with a stark paucity of research into the effects of processing methods on quality and the mechanisms by which substances influence the quality during its formation.This has substantially hampered the enhancement of American ginseng processing methodologies and further quality improvements,adversely affecting the introduction of novel technologies and the evolution of "superior quality" and "highly effective" products.Heat treatment,a common method in the food industry,underpins the transformation of active ingredients in food,rendering variability in its functional value under disparate thermal processing conditions.Thus,investigating the mechanisms of quality formation and the selection of functional substances under varying heat treatment deep processing methods for American ginseng holds paramount importance.Leveraging this as a foundation to expand the processing techniques of American ginseng could boost its utilization efficiency and augment its nutritional value.In this study,a comprehensive assessment of moisture migration patterns,hue,physicochemical properties,and biological activity was conducted on American ginseng and black ginseng with different processing methods were clarified,thereby elucidating the impact of disparate processing techniques on the quality of American ginseng.Delving into the quality indices and integrating chemometrics with correlation analysis shed light on the mechanisms by which different processing approaches influence quality formation.Building on this foundation,the research ventured into screening for distinct metabolites and potential anti-inflammatory active components in American ginseng processed by various methods.The analysis of their mechanism mechanisms of activity offers a theoretical scaffold for the investigation into the functional substance base and action mechanisms of American ginseng.The research results on American Ginseng are as follows:(1)Impact of drying temperature on characteristics and quality of American ginsengThe analysis of drying kinetics models combined with low-field nuclear magnetic resonance technology shows that moisture diffusion during the drying process can be divided into three stages.The Henderson and Pabis model is identified as the best model to describe the drying process of American ginseng,initially characterized by a rapid reduction of free water.At 30°C,40°C,and 50°C,the inflection point to the second phase is reached after 168,48,and 24 hours,respectively,primarily dominated by the reduction of immobile water and bound water.Towards the end of drying,bound water predominantly constitutes the moisture content.A comprehensive evaluation of color and the concentrations of ginsenosides Rg1,Re,and Rb1 indicates that drying temperature significantly affects browning and the degradation reactions of ginsenosides.The drying duration at 50°C is reduced by 70.0% and 35.7% compared to 30°C and 40°C,respectively,due to its relatively higher total ginsenoside content,making it the optimal temperature for drying processing.(2)Quality evaluation of American Ginseng under different processing methodsThe impact of different processing methods on the quality of American Ginseng was assessed through a comprehensive evaluation of low-temperature softened-hot-air dried,blanched-hot-air dried,steamed-hot-air dried,and vacuum freeze-dried processes.The vacuum freeze-dried method demonstrated the highest brightness value(ΔL*=-3.4±0.08),showing distinct vascular bundles and starch granules.The ginsenoside Rg1 and Rb1 content in samples processed by low-temperature softened-hot-air dried were2.65 and 0.51 times higher respectively,than those processed by vacuum freeze-dried.Samples subjected to steamed-hot-air dried exhibited a reddish-brown hue,the genesis of new ginsenosides Rg6,20(S)-Rg3,20(R)-Rg3,Rk1,and Rg5,and possessed enhanced antioxidant activity.The quality of the blanched-hot-air dried samples was intermediate compared to the aforementioned methods,but the drying time to reach the safe water content is the shortest(15.5 h).A total of 58 volatile compounds were identified using gas chromatography-ion mobility spectrometry,with hierarchical clustering analysis and principal component analysis facilitating the separation of the four processed products and the screening for correlating characteristic components.Correlation analysis between color parameters,volatile and ginsenoside components,and antioxidant activity revealed significant interrelations among different quality indices.Ginsenosides Rg1 and Rb1 were positively correlated with DPPH,ABTS radical cation scavenging activity,and FRAP,in which Rb1 had a significant correlation coefficient of 0.91,0.83,0.98(P < 0.05),and could be used as a potential antioxidant active component.(3)Quality evaluation of black ginseng produced through different processing methods and the formation mechanism of quality with nine-steaming and nine-making black ginsengComparative evaluations of the color,principal components,and antioxidant activities of black ginseng produced through nine-steaming and nine-making,highpressure steaming,and high-temperature high-humidity processes were conducted,with vacuum freeze-dried American ginseng serving as the control.All three black ginseng samples exhibited a dark brown coloration,with the high-pressure steaming black ginseng displaying a deeper hue and the highest content of 5-hydroxymethylfurfural(12.99±0.14 mg/g).The high-temperature high-humidity process yielded the highest levels of reducing sugars,arginine,and lysine(43.71±3.80%,0.62±0.001%,and 0.11±0.001% respectively).The nine-steaming and nine-making process had the highest total ginsenoside content(95.63±0.70 mg/g).Both the nine-steaming and nine-making and high-pressure steam processes demonstrated stronger antioxidant activities,with DPPH clearance rates of 87.59±9.29% and91.80±4.70%,respectively,and ABTS radical cation scavenging rates and ferric reducing antioxidant power(FRAP)of 1.00±0.04 m M,1.06±0.00 m M Trolox/g,and0.49±0.01 m M,0.48±0.06 m M Fe(Ⅱ)/g DW,respectively.During the steaming of the nine-steaming and nine-making black ginseng,moisture progressively migrated from the inside out,stabilizing the relaxation times T23,T22,and T21 after the second steaming,indicating a gradual decline in moisture mobility.After nine steaming,the proportion of bound water reached 64.04%.Polysaccharides,ginsenosides,acetylated or esterified glucuronic acids were detected through infrared absorption peaks in samples from varying steaming cycles.With increased steaming,internal tissue fissures and irregular protrusions developed within the samples.Throughout the steaming process,the contents of ginsenosides.(4)Screening of action of anti-inflammatory active substances in black ginseng and mechanism of anti-inflammatory activity of ginsenoside Rg5Based on a "metabolomics-spectrum-effect relationship" comprehensive strategy,using extensive non-targeted metabolomics technology,418 metabolites were identified in American Ginseng processed through different methods.Further PCA and OPLS-DA analysis indicated significant differences in metabolites among the samples processed by various methods.Using the t-test analysis on samples processed through different methods,based on calculated P values and FC values(P < 0.05,FC > 2.0),347 differential metabolites were ultimately screened.A high-performance liquid chromatography-diode array detector method was established for the fingerprinting of black ginseng samples prepared from American Ginseng of different origins,identifying 14 common peaks as ginsenosides Re,Rb1,Rc,Rg2,Rh1,Rb2,Rd,Rg6,Rg4,F2,Rg3,RS3,Rk1,and Rg5.Using the release amounts of NO,IL-6,and TNF-αin LPS-induced RAW264.7 cells as variables,grey relational analysis and partial least squares regression analysis were conducted,identifying ginsenosides Rg2,Rh1,Rb2,Rk1,and Rg5.By comparison with differential metabolites from metabolomics,Rg2,Rk1,and Rg5 were determined as potential anti-inflammatory active components.The study on the anti-inflammatory mechanism of action of ginsenoside Rg5 shows that it alleviates inflammation in LPS-induced RAW264.7 cells by reducing the release of NO,IL-6,and TNF-α and inhibiting the generation of oxidative stress ROS.Additionally,it exerts anti-inflammatory effects by downregulating the expression of COX-2 and i NOS proteins and the activation of the NF-κB/JAK2/STAT3 signaling pathway.Molecular docking results indicated that Rg5 binds effectively with JAK2 and STAT3 proteins,acting on the JAK2/STAT3 signaling pathway to exert its anti-inflammatory effects. |
PDF Full Text Request