Changes over time in the saponin constituents of fresh ginseng powder thermally treated at 105℃ were examined. Specimens of fresh ginseng thermally treated for different times revealed continuous increases in protopanaxadiol(PPD) type ginsenosides of GS-Rb1, Rb2, Rc and Rd, among the major saponins for up to three hours. However, their concentrations diminished after three hours and the Rb1, Rb2, and Rd became undetectable after 30 hours, while Rc was not detected after 27 hours. Rg3, a degradation product of PPD type ginsenosides, reached its peak values after 30 hours of complete decomposition of GS-Rb1, Rb2, Rc, and Rd, and remained without significant variation in concentration for some time, but after about 40 hours, it began to decrease (Table 2 and Fig. 1).
Conversely, the GS-Rg1 and Re, the major saponins of the protopanaxatriol (PPT) type ginsenosides, exhibited a slight increase for up to two hours of heating, and then decreased after 2.5 hours; Re, Rg1, and Rf were not detected after 16 hours, 24 hours, and 33 hours, respectively. Rg2, known as a degradation product of GS-Re, showed maximum concentration after 12 hours, and then decreased gradually. The degradation product of GS-Rg1, the GS-Rh1, increased inversely with the degradation of GS-Rg1. The degradation product of GS-Re, the GS-Rg2, also exhibited inverse proportional increase concomitant with degradation of GS-Re (Table 3 and Fig 1). The creation of GS-Rg5 and Rk1 from the dehydration reaction of carbon at position C-20 of GS-Rg3 was identified from examining the content before and after heating fresh ginseng at 105℃.
The creation of GS-Rg5 and Rk1 were also identified from the mass analysis of LC/mass (Table 4 and Figs 2 - 4). Following heat treatment of specimens of fresh ginseng at 94℃, the increase in content of GS-Rb1 and the decrease in content of GS-Rg3, were examined. In the graph illustrating the results, the concentration of GS-Rb1 reached its peak after six hours, but then became undetectable by 30 hours at 105℃ and 48 hours at 94℃ (Table 5).
Changes in the major GS’s at a temperature of 80℃, were examined. As presented in Table 6, the concentration of GS-Rb1 reached its peak after 48 hours (2 days), while the content of GS-Rg3 reached its peak after 12 days from heat treatment, and then it started to decrease after 500 hours. Upon completion of heat application with steam at 120℃ to red ginseng of moisture content 30%, the rise and fall in the content of GS-Rb1 over time was examined. Its content increased after one hour and then decreased, and became undetectable after four hours of heat application (Table 7).
The major GS’s of fresh ginseng, GS-Rb1, Rb2, Rc, and Rd, appeared to initially increase following heat treatment and our analysis identified the conditions, under which peak levels of all the major GS were created. Furthermore, we were able to define the degradation kinetics of GS-Rg3, Rg2, and Rh1 in fresh ginseng. It was found that a large amount of GS-Rk1 and Rg5 etc. was created in accordance with the increasing time of heat treatment [6-8].
For the manufacturing of red ginseng, the conditions, satisfying maximum concentrations of major GS of the fresh ginseng (GS-Rb1, Rb2, Rc, and Rd), were less than one hour at 120℃ and 2.5 - 3 hours at 105℃. The time to peak concentration of Rb1 at 94℃ and 80℃ took longer at lower temperatures. Thus, for the manufacturing of the red ginseng, it is predicted that the longer heating time at lower temperature or shorter heating time at higher temperature are necessary to obtain maximum concentrations of the seven kinds of major GS.
The reductions in GS-Rd with time is less than was seen for GS-Rb1, Rb2, and Rc. This is because the decomposition of PPDs GS-Rb1, Rb2, and Rc, results in GS-Rg3 via conversion into GS–Rd [8-10].
The increase in PPD type GSs upon initial heating resulted from the release of the malonyl group from malonyl-PPDs. Under identical conditions, the rate of decomposition of the GS of the PPTs was faster than the GS of the PPD-type except for the GS Rf. The conversion ratio of GS-Rh1 resulting from GS-Rg1 and of GS-Rg2 resulting from GS-Re, appeared lower than that of Rg3, which is known to be a degradation product of GS-Rb1, Rb2, Rc, and Rd of the PPD-type
This implies the presence of relatively lower content of the malonyl-PPT than the malonyl-PPD . The lower rate of decomposition of GS-Rf can be attributed to the bonding of the OH-group such as carbon at C-20 position of GS-Rg2, the degradation product of GS-Re . Yang et al.  reported the major GS in fresh ginseng decreased significantly in accordance with the increasing number of steaming treatments, while the (content of) GS-Rg3 appeared increased. However, in the study by Yang et al., the initial increase or decrease in concentration of GS was unavailable due to the lack of detailed measurements during initial steaming. In another study by Kim et al. , factors, inducing concentration changes, were not clarified because of the use of specimens for which drying temperature information was not provided.
Go et al.  reported results on ingredients of GS included in the extracted concentrates of commercially available white ginseng and red ginseng, wherein the extracted concentrate of white ginseng appeared to have higher GS content than red ginseng. The differences in content of GS-Rb1, Rb2, Rc, and Rd were attributed to differences in the heat treatment used in respective manufacturing processes, wherein red ginseng used a longer duration of heat application for the processes of extraction and concentration, whereas white ginseng had heat applied for a shorter length of time.
Nam et al.  used six-year-old roots of the fresh ginseng and repeated the treatment of steaming for three hours at 96℃ and drying at 50℃. The method resulted in red ginseng of moisture content below 15% - 20% after drying, therefore the samples may exhibit less or uneven moisture content, that may cause differences in the rate of hydrolysis of GS compared to fresh ginseng, with moisture content of approximately 75% - 80%. In this study, the factors, that caused changes in GS content according to treatment of steaming, were identified as the time and temperature of steaming.
In all of the GS-Aglycon of ginseng, the Glc-Glc, bonded with C3 or C6 and was dropped-off from the position at C20, suggesting the decomposition reaction is induced by acid. At the C20 position, the results of hydrolysis, caused by hydrolytic enzyme, were not reported because of the presence of steric hindrance. The difference in electron density based on theoretical calculation could be a factor behind the increasing reaction at C20 .
The weight of hydrolysate decreased compared to the concentration of GS’s of PPD types. This resulted from the decomposition of Glc(2-1)Glc bonded with GS-Aglycon thereby converted into GS-Rg3 of molecular weight of 785 g/mol compared to the weight of 1,109 g/mol of GS-Rb1. Such properties can be observed from similar reactions of GS Rg1 and Re . The ingredients of GS Rg3, Rg5, and Rk1 of PPD saponins, are unique components of red ginseng resulting from processing via heat treatment, and have been reported to exhibit diverse pharmacological activities. However, the corresponding components contained in red ginseng are rare. The efficacy of ginseng can be augmented by increasing the concentration of such ingredients. Thus, it is predicted that the conditions by which boiling water is used for the decoction of ingredients of red ginseng as in the traditional way, would result in increased levels of GS Rg3, Rg2, Rg5, and Rk1 in red ginseng [17-21].