Influence of organic acids and heat treatment on ginsenoside conversion

Abstract

BackgroundHeat treatments are applied to ginseng products in order to improve physiological activities through the conversion of ginsenosides, which are key bioactive components. During heat treatment, organic acids can affect ginsenoside conversion. Therefore, the influence of organic acids during heat treatment should be considered.MethodsRaw ginseng, crude saponin, and ginsenoside Rb1 standard with different organic acids were treated at 130°C, and the chemical components, including ginsenosides and organic acids, were analyzed.ResultsThe organic acid content in raw ginseng was 5.55%. Organic acids were not detected in crude saponin that was not subjected to heat treatment, whereas organic acids were found in crude saponin subjected to heat treatment. Major ginsenosides (Rb1, Re, and Rg1) in ginseng and crude saponin were converted to minor ginsenosides at 130°C; the ginsenoside Rb1 standard was very stable in the absence of organic acids and was converted into minor ginsenosides in the presence of organic acids at high temperatures.ConclusionThe major factor affecting ginsenoside conversion was organic acids in ginseng. Therefore, the organic acid content as well as ginsenoside content and processing conditions should be considered important factors affecting the quality of ginseng products.

Effects of immersion in fermented tea liquid and steam treatments on physicochemical properties and ginsenoside profiles of Korean ginseng

“…(2011) and Jang et al. (2018) suggested that organic acids in combination with heat treatment be used to improve bioactive components through the conversion of major ginsenosides to minor ginsenosides, which was also observed in this study (Tables 3 and 6), where immersion in acidic FTL and steam treatment were applied.…”

“…Several researchers have attempted to enhance ginsenosides in Korean ginseng using organic acids and heat treatment. They reported that organic acids such as acetic acid, ascorbic acid, citric acid, malic acid, lactic acid, and oxalic acid could convert neutral ginsenosides to rare ginsenosides, resulting in improved functionality of ginseng, hence increasing its value (Jang et al., 2018; Kim et al., 2010; Liu et al., 2016; Yi et al., 2010). After heat treatment, the major ginsenosides could be converted to low‐polar ginsenosides such as Rg2, Rg6, F4, Rk3, and Rg5 by hydrolysing the sugar chains (Kim et al., 2013; Zhang et al., 2012).…”

Stem-leaves of Panax as a rich and sustainable source of less-polar ginsenosides: comparison of ginsenosides from Panax ginseng, American ginseng and Panax notoginseng prepared by heating and acid treatment

“…According to a previous report, the Rb1/Rg1 ratio in PG is usually between 1 and 3, while Rb1/Rg1 values of approximately 10 or greater are characteristic of AG [ 29 ]. With the popularity of mass spectrometry, some trace markers such as Rf, p-F11 and Rs1 can also be used for differentiating PG from PQ [ 30 ]. Notoginsenoside R1 was only observed in NG.…”

Diversity of Ginsenoside Profiles Produced by Various Processing Technologies

“…Some studies also found that treatment of ginsenosides Rh1, Rh2, and Rg3 with 0.01% formic acid at 120 °C for 4 h resulted in the formation of ginsenosides Rk3 and Rh4, Rk1 and Rg5, and Rk2 and Rh3, respectively [ 93 ]. In addition, through acid hydrolysis, an addition reaction, and dehydration, formic acid promotes the transformation from ginsenosides Re, Rf, and Rg2 into several minor ginsenosides, i.e., F1, Rh1, Rf2, Rf3, Rg6, F4, and Rg9 [ 94 , 95 ]. Besides citric acid and formic acid, other acids, such as acetic acid, ascorbic acid, and lactic acid, can also be used in the chemical transformation of major ginsenosides into minor ginsenosides in ginseng samples [ 96 , 97 ].…”