Optimization of Extraction Conditions for the 6-Shogaol-rich Extract from Ginger (Zingiber officinale Roscoe)

Abstract

6-Shogaol, a dehydrated form of 6-gingerol, is a minor component in ginger (Zingiber officinale Roscoe) and has recently been reported to have more potent bioactivity than 6-gingerol. Based on the thermal instability of gingerols (their dehydration to corresponding shogaols at high temperature), we aimed to develop an optimal process to maximize the 6-shogaol content during ginger extraction by modulating temperature and pH. Fresh gingers were dried under various conditions: freeze-, room temperature (RT)- or convection oven-drying at 60 or 80°C, and extracted by 95% ethanol at RT, 60 or 80°C. The content of 6-shogaol was augmented by increasing both drying and extraction temperatures. The highest production of 6-shogaol was achieved at 80°C extraction after drying at the same temperature and the content of 6-shogaol was about 7-fold compared to the lowest producing process by freezing and extraction at RT. Adjustment of pH (pH 1, 4, 7 and 10) for the 6-shogaol-richest extract (dried and extracted both at 80°C) also affected the chemical composition of ginger and the yield of 6-shogaol was maximized at the most acidic condition of pH 1. Taken together, the current study shows for the first time that a maximized production of 6-shogaol can be achieved during practical drying and extraction process of ginger by increasing both drying and extracting temperatures. Adjustment of pH to extraction solvent with strong acid also helps increase the production of 6-shogaol. Our data could be usefully employed in the fields of food processing as well as nutraceutical industry.

Antifungal and anti‐biofilm effects of 6‐shogaol againstCandida auris

“…2008; Dugasani et al . 2010; Ok and Jeong 2012). 6‐shogaol is a dehydrated product of 6‐gingerol extracted from ginger ( Zingiber officinale ) (Ling et al .…”

Gingerols and shogaols: Important nutraceutical principles from ginger

“…These compounds are thermally labile and are transformed at high temperatures to shogaols (SGs), which impart a pungent and spicy-sweet fragrance (Wohlmuth et al, 2005). During the preparation of dried ginger, GNs are also rapidly converted to the corresponding SGs, of which 6-SG is the most common dehydration product (Ok and Jeong, 2012). In many cases, 6-SG has been reported to have better biological activities than 6-GN.…”

Thermal activities of 6-gingerol, 8-gingerol and 6-shogaol on the potentiation of mitochondria thermogenesis based on microcalorimetry

“…8-Gingerol, presenting in a lower concentration, also contributes to the 'hot' property of ZR [22]. And shogaols, which are transformed from gingerols at high temperature [23,24], impart a pungent and spicy fragrance as well.…”