Incidence of fungal contamination in fresh ginseng samples and mycotoxigenic potential of representative fungal isolates

BACKGROUND

Fresh ginseng is typically accompanied by soil after harvest, leading to contamination with harmful fungi during storage and distribution. In this study, we investigated the incidence of fungal contamination in fresh ginseng (5-6 years old) purchased from 22 different stores in Geumsan, Korea.

RESULTS

The incidence of fungal contamination in the samples was 67.4-111.5%. Fusarium solani was the most abundant species in the head (38.5%) and fine root (19.3%) parts of the ginseng samples, whereas F. oxysporum was the most abundant in the main root (22.0%) part. We isolated Aspergillus, Fusarium and Penicillium spp. (total number of isolates: 395) from the ginseng samples, and 138 isolates were identified using phylogenetic analysis. Polymerase chain reaction-based screening of 65 mycotoxin-producing species revealed that two P. expansum isolates were positive for citrinin and/or patulin, and five F. oxysporum isolates were positive for fumonisin biosynthesis gene. One P. expansum isolate produced 738.0 mg kg-1 patulin, and the other produced 10.4 mg kg-1 citrinin and 12.0 mg kg-1 patulin on potato dextrose agar (PDA) medium. Among the 47 representative F. oxysporum isolates, 43 (91.5%) produced beauvericin (0.1-15.4 mg kg-1) and four of them (8.5%) produced enniatin B and enniatin B1 (0.1-1.8 mg kg-1) as well. However, none of these toxins was detected in fresh ginseng samples.

CONCLUSION

Fusarium solani and F. oxysporum were the most abundant species in fresh ginseng samples. Most F. oxysporum (43) and P. expansum (2) strains isolated from fresh ginseng produced beauvericin and enniatins (B and B1), and patulin or citrinin, respectively, on PDA medium. This is the first report of the mycotoxigenic potential of P. expansum and F. oxysporum strains isolated from fresh ginseng. © 2024 Society of Chemical Industry.

Effects of different substrates on low-temperature storage of fresh ginseng

BACKGROUND

Fresh ginseng was buried in three types of sand with different moisture contents and three types of soil and then stored at 2 °C to determine the effects of these storage substrates on fresh ginseng.

RESULTS

At a storage time of 200 days, ginseng stored in underforest soil softened the most slowly and had a significantly greater firmness compared to the other samples (P < 0.05). The amount of most ginsenosides changed after storage for most of the substrates. Samples stored in ginseng soil and biological fertilizer had the highest concentration of total saponin and ginseng polysaccharides, respectively. Fresh ginseng stored in medium-water content sand had a significantly lower polyphenol oxidase activity (P < 0.05). A significant difference was observed in the total concentration of nucleosides and nucleobases between the ginseng samples stored with and without substrates (P < 0.05).

CONCLUSION

The data obtained in the present study suggest that the use of storage substrates is an optimal method for extending the shelf life of fresh ginseng without detrimental effects on its components. © 2019 Society of Chemical Industry.

Study on the Correlation between Gene Expression and Enzyme Activity of Seven Key Enzymes and Ginsenoside Content in Ginseng in Over Time in Ji'an, China

Panax ginseng is a traditional medicine. Fresh ginseng is one of the most important industries related to ginseng development, and fresh ginseng of varying ages has different medicinal properties. Previous research has not systematically reported the correlation between changes in key enzyme activity with changes in ginsenoside content in fresh ginseng over time. In this study, for the first time, we use ginseng samples of varying ages in Ji'an and systematically reported the changes in the activity of seven key enzymes (HMGR, FPS, SS, SE, DS, CYP450, and GT). We investigated the content of ginsenoside and gene expression of these key enzymes. Ginsenoside content was measured using HPLC. HPLC, GC-MS, and LC-MS were combined to measure the enzyme activity of the key enzymes. Quantitative PCR was used in the investigation of gene expression. By analyzing the correlation between the enzyme activity and the transcription level of the key enzymes with ginsenoside content, we found that DS and GT enzyme activities are significantly correlated with the ginsenoside content in different ages of ginseng. Our findings might provide a new strategy to discriminate between ginseng of different years. Meanwhile, this research provides important information for the in-depth study of ginsenoside biosynthesis.

Effect of high hydrostatic pressure extract of fresh ginseng on adipogenesis in 3T3-L1 adipocytes

BACKGROUND

Red ginseng is produced by steaming and drying fresh ginseng. Through this processing, chemical compounds are modified, and then biological activities are changed. In the food-processing industry, high hydrostatic pressure (HHP) has become an alternative to heat processing to make maximum use of bioactive compounds in food materials. This study comparatively investigated the anti-adipogenic effects of water extract of red ginseng (WRG) and high hydrostatic pressure extract of fresh ginseng (HPG) in 3T3-L1 adipocytes.

RESULTS

Both WRG and HPG inhibited the accumulation of intracellular lipids and triglycerides, and the activity of glycerol-3-phosphate dehydrogenase (GPDH), a key enzyme in triglyceride biosynthesis. Intracellular lipid content and GPDH activity were significantly lower in the HPG group compared to the WRG group. In addition, mRNA expression of adipogenic genes, including CEBP-α, SREBP-1c and aP2, were lower in HPG-treated cells compared to WRG-treated cells. HPG significantly increased the activity of AMPK, and WRG did not.

CONCLUSION

Results suggested that HPG may have superior beneficial effects on the inhibition of adipogenesis compared with WRG. The anti-adipogenic effects of HPG were partially associated with the inhibition of GPDH activity, suppression of adipogenic gene expression and activation of AMPK in 3T3-L1 adipocytes.