Selection and application of aptamers for p-hydroxybenzyl hydrogen sulfite after Gastrodia elata Bl. fumigated with sulfur.

Gastrodia elata Bl. is a widely used traditional Chinese medicine known for its medicinal properties. However, during the drying process, G. elata is often fumigated with sulfur to prevent corrosion and improve its appearance. Sulfur-fumigation can result in a reduction in the effective components of the herb and can also be hazardous to human health due to the remaining sulfur dioxide. Sulfur-fumigation of G. elata poses a significant challenge to both end-users and researchers. The detection of p-hydroxybenzyl hydrogen sulfite (p-HS) is a useful tool in determining whether G. elata has been fumigated with sulfur. Unfortunately, the current method for detecting p-HS is costly and requires sophisticated instruments. Therefore, there is a need to develop a more cost-effective and user-friendly method for the detection of p-HS. This study utilized the Capture-SELEX technique to screen high-affinity aptamers for p-HS, which were subsequently characterized by isothermal titration calorimetry (ITC). An aptamer sequence (seq 6) with a high affinity of Kd = 26.5 µM was obtained following 8 rounds of selection against p-HS. With the aptamer serving as the recognition element and gold nanoparticles as the colorimetric indicator, a simple and efficient colorimetric sensor was developed for the specific detection of p-HS. This detection method exhibited a limit of detection of 1 µg/ml, while the p-HS recoveries demonstrated a range of between 88.5 % and 105 % for samples of G. elata obtained in the market. In summary, the aptamer exhibited a high affinity for p-HS, and the sensor developed through the use of a colloidal gold detector based on nucleic acid aptamer can be utilized for rapid detection of sulfur-fumigated G. elata. With these findings, this research paper provides valuable scientific insights and highlights significant potential for future studies in this area.

Evaluate how steaming and sulfur fumigation change the microstructure, physicochemical properties and in vitro digestibility of Gastrodia elata Bl. starch.

The sulfur dioxide gas (SO2) generated by sulfur burning can improve the appearance quality of food and enhance the storage time. However, excessive sulfur dioxide will pollute the environment and cause deterioration of food quality, and even the high residual levels can increase the risk of cancer. As Gastrodia elata Blume is prone to corruption during processing, sulfur fumigation is often used for preservation. In this study, spectral analysis and Texture Profile Analysis (TPA) were used to investigate the effects of traditional sulfur fumigation processing on the morphology quality, edible quality and structural characteristics of G. elata. The results showed that compared with direct drying, the pH decreased by 0.399 of the sulfur fumigated after steamed treatment G. elata, and the morphology quality, pasting ability and gel edible quality of the starch were significantly improved. In addition, it was suggested that sulfur fumigation after steaming could promote the release of molecular chains from starch granules and thus enhance the cross-linking between molecules, which explained the reason for the improve of starch edible quality. This study can provide technical and theoretical support for improving the quality of starch rich foods, replacing sulfur fumigation and reducing potential environmental hazards.