Heat-induced conversion of gingerols to shogaols in ginger as affected by heat type (dry or moist heat), sample type (fresh or dried), temperature and time

Mun Yhung Jung; Min Kyoung Lee; Hee Jeong Park; Eun-Bi Oh; Je Young Shin; Ji Su Park; Su Young Jung; Jung-Hee Oh; Dong-Seong Choi

doi:10.1007/s10068-017-0301-1

Heat-induced conversion of gingerols to shogaols in ginger as affected by heat type (dry or moist heat), sample type (fresh or dried), temperature and time

Food Sci Biotechnol. 2017 Dec 29;27(3):687-693. doi: 10.1007/s10068-017-0301-1. eCollection 2018 Jun.

Authors

Mun Yhung Jung¹, Min Kyoung Lee¹, Hee Jeong Park¹, Eun-Bi Oh¹, Je Young Shin¹, Ji Su Park^{1

2}, Su Young Jung³, Jung-Hee Oh³, Dong-Seong Choi¹

Affiliations

¹ 1Department of Food and Biotechnology, Graduate School, Woosuk University, Samnye-Eup, Wanju-Gun, Jeonbuk Province 55338 Republic of Korea.
² 2Food Analysis Center, Korea Food Research Institute, Wanju-Gun, Jeonbuk Province 55365 Republic of Korea.
³ Healthy Local Food Branding Agency, Wanju, Jeonbuk Republic of Korea.

Abstract

The impact of heat type, sample type, temperature and time on the heat-induced conversion of gingerols to shogaols in ginger were studied by an UHPLC-ESI-MS/MS. Heat treatments greatly induced the conversion of gingerols to shogaols in ginger. As the temperature increased, the faster conversion of gingerols into shogaols were observed. However, the efficiency of the heat-induced conversion differed greatly with the heat types. Moist heat treatment induced significantly higher quantity of shogaols than dry heat treatment. The moist heat treatment at 120 °C for 360 min induced the highest conversion, reaching to 2991 mg 6-shogaol per kg ginger. In addition, dry-heat induced conversion was affected by the sample type. The dry-heat treatment on dried powder induced significantly higher quantity of shogaols than that on sliced fresh ginger. This represents the first systematic comparative study on the heat and sample types on the heat-induced conversion of gingerols into shogaols in ginger.

Keywords: Dry heat; Ginger powder; Gingerol and shogaol; Moist heat; UHPLC–ESI–MS/MS.