Microwave-assisted decomposition coupled with acidic food condiment as an efficient technology for ginger (Zingiber officinale Roscoe) processing

•The microwave-assisted process provides highly efficient conversion.•Tartaric acid is the best catalyst for the conversion of gingerols into shogaols.•This method gains higher shogaols contents than previously reported techniques.

Shogaols are the dehydration products of gingerols that are found in small quantities in ginger root and have more potent bioactive properties than gingerols. In this study, microwave-assisted technology coupled with acidic food condiments was used to improve the contents of 6-, 8-, and 10-shogaols. After processing ginger in aqueous tartaric acid solution (0.8 mol/L, 8 mL) at 140 °C and 1000 W for 10 min, the contents of 6-, 8-, and 10-shogaols (4.66, 1.19, and 1.76 mg/g dry mass, respectively) were approximately 12-, 17-, and 19-fold higher in processed ginger than in unprocessed ginger. The antioxidant capabilities of this processed ginger were approximately two times higher than those of unprocessed ginger assayed by antioxidant assays. The processed gingers can be used as high-quality raw materials for the production of various ginger products, as well as for the preparative separation and purification of 6-, 8-, and 10-shogaols.