Determination of Gingerols and Shogaols Content from Ginger (Zingiber officinale Rosc.) through Microwave-Assisted Extraction

Ginger (Zingiber officinale Rosc.) is a plant recognized for its pungent taste and aromatic qualities, primarily derived from its underground rhizome. Apart from its widespread culinary applications, ginger is valued for its potential health benefits attributed to the presence of gingerols and shogaols. For this reason, this work proposes the development of a microwave-assisted extraction (MAE) method for the extraction of gingerols and shogaols present in ginger rhizomes. The influence of the extraction temperature (50–100 °C), the solvent composition (50–100% ethanol in water), and the sample-to-solvent ratio (0.3–0.7 g sample: 20 mL) on the extraction of these bioactive compounds has been studied. To this end, a Box–Behnken experimental design (BBD) in combination with a response surface methodology (RSM) has been applied. The optimum conditions for the total extraction of gingerols and shogaols were: 87% ethanol in water, 100 °C, and 0.431 g of ginger sample in 20 mL solvent. The developed method required short extraction times (5 min) and demonstrated favorable levels of repeatability and intermediate precision (CV < 5%). Finally, the MAE method was successfully used for the extraction of gingerols and shogaols from a variety of ginger samples.