Abstract: In the present study, to extend shelf-life, we investigated the changes in the physicochemical and microbiological qualities of fresh ginseng packaged in nitrogen atmosphere during storage at 4, 37 and 45 ℃. Further, the changes in total saponin content and moisture content during storage at different temperatures were monitored and a first-order kinetic model was established describing the effect of storage temperature on total saponin content. The results showed that moisture and total saponin contents in fresh ginseng generally decreased with increasing storage temperature. At 37 ℃, the total number of colonies on the surface of fresh ginseng increased with storage time, while the opposite was observed at 45 ℃. The proposed first-order kinetic model had good fitness (R2 > 0.94) and the temperature-dependent variation of total saponin content was well described by the Arrhenius equation. The shelf-life of nitrogen-packed fresh ginseng at different temperatures could be predicted based on the changes in total saponin content. The validation experiments showed that the relative error of the prediction was less than 10%.

Key words: nitrogen-packed, fresh ginseng, kinetic model, shelf-life