Agricultural pesticide-free ginseng extract

In the early days, the pesticide residues in ginseng mainly included traditional pesticides such as organochlorines, organophosphates, and pyrethroids. Later, with the emergence of drug resistance and restrictions on pesticide use policies, the types of pesticides also changed. New pesticides such as amides, dicarboximides, and triazoles have been used in the prevention and control of ginseng diseases. The use of new pesticides can improve the ability to control pests and diseases. For example, propiconazole, dimethomorph, and cyproconazole can effectively control black spot disease in ginseng, but they also cause the problem of excessive types of pesticide residues in ginseng.

Processing

The history of ginseng processing originated in the Han Dynasty, and there are various processing methods. Modern processing of ginseng mainly includes raw sun-dried ginseng, red ginseng, and strong ginseng.

However, studies have found that there is no significant change in the amount of pesticide residues in ginseng before and after processing. Different processing methods have little effect on the pesticide residues in ginseng and basically cannot reduce the pesticide residues in ginseng.

Therefore, it is difficult to produce ginseng products without pesticide residues through traditional processing methods.

Residue-free ginseng raw powder

The cleaning of fresh ginseng can only remove the pesticide residues on the surface and those carried by the soil. Mechanical cleaning is also difficult to remove the pesticide residues that are well adsorbed by the fibers. Therefore, the processing of ginseng raw powder without pesticide residues is quite challenging and it is hard to obtain an ideal product.

Ginseng polysaccharides

It is relatively easier to obtain ginseng polysaccharides without pesticide residues. This is because the processing of polysaccharides involves a preliminary step of extracting and separating ginsenosides using solvents. As ginsenosides act as surfactants, they enhance the extraction capacity of the solvents. Thus, complete extraction of ginsenosides can lead to the complete transfer of pesticide residues, ultimately resulting in ginseng polysaccharides free of pesticide residues.

In addition, the refining process of ginseng polysaccharides involves solvent washing and crystallization, which further enhance the separation of polysaccharides from pesticide residues.

Ginsenosides

Ginsenosides are a typical type of surfactant, with solubilizing and emulsifying properties. Therefore, the treatment of any impurities in ginsenosides is extremely difficult and requires a significant cost. During the extraction of ginseng, a frustrating situation may occur where pesticides that were originally not in contact with the ginsenosides may dissolve and fully mix with them. Another headache is that due to the action of ginsenosides, pesticides and lipids with similar polarity in ginseng can smoothly transfer from ginseng to the mixed system of solvent and ginsenosides, eventually forming a stable system both kinetically and thermodynamically. This means that any method for completely removing pesticide residues must deal with the complete and thorough changes in the mixed system in terms of kinetics and thermodynamics. In other words, the entire process requires a large investment and significant changes. Before and after the treatment, we will be dealing with two completely different systems. Whether they can still be regarded as slightly different forms of the same substance is a matter that needs serious discussion.

The basic methods for separating ginsenosides from pesticide residues include solid-liquid separation using adsorbents and liquid-liquid separation using two immiscible liquids. The large difference in the solubility of ginsenosides or pesticides in the two solvents is sufficient to create a chemical potential for separation.

Due to the extraordinary ability of ginsenosides to sacrifice themselves, it is almost impossible to find a selective adsorbent or solvent with an ideal separation effect. Therefore, accepting a significant loss of ginsenosides, for example, 60%, is a wise choice. In fact, this is smart because when the loss reaches a certain level, it precisely indicates that the choice of adsorbent or solvent is reasonable.

A reasonable low yield has clear advantages in industry. Because a clear and effective endpoint determination method is far more in line with the spirit of quality management than investing millions of dollars in equipment and hiring experienced inspectors. A reproducible and acceptable low yield is more industrial in nature and more favored by experienced workshop managers than a high-investment and high-difficulty test with poor reproducibility and timeliness.

Ginsenosides can easily increase the viscosity of the solution system, which is also an undesirable property for production. High viscosity is an unbearable torment for adsorption and the complete phase separation required for extraction.

Therefore, the formation of methods for handling ginseng pesticide residues is not about the choice of resin or solvent, but about the choice of ginsenosides. Whether one truly understands ginsenosides and recognizes surfactants may be the key issue.