Evaluation of spices and oleoresin‐VI‐pungency of ginger components, gingerols and shogoals and quality

Abstract

The pungent compounds of ginger had earlier been shown to be homologous gingerols, the dehydration product shogaols and the degradation product zingerone. The changes in these compounds are reported to affect quality with reduction in pungency and formation of off-flavour. Contrary to earlier assumptions, careful threshold tests for pungency of different oleoresins and purified pungent isolates, gingerols and shogaols established that shogaols are twice as pungent as gingerols. With this ratio of pungency of gingerols and shogaols, the calculated values agreed well with the estimated values of pungency in different ginger oleoresin samples. Occurrence of other non-pungent phenolics with close Rf values to the pungent compounds have been confirmed.

Pungent and volatile constituents of dried Australian ginger

“…The proportion of gingerols converted to shogaols depends on the drying temperature, but can approach ∼50% conversion under very high drying temperatures (180 °C) ( Ghasemzadeh et al, 2018 ). As shogaols are twice as pungent as gingerols ( Narasimhan & Govindarajan, 1978 ), this increases the pungency of dried ginger proportionally. Furthermore, shogaols also show higher bioactive and medicinal properties ( Ghasemzadeh et al, 2018 ) compared to their respective gingerols ( Wei et al, 2005 ).…”

A Rapid Non-Destructive Hyperspectral Imaging Data Model for the Prediction of Pungent Constituents in Dried Ginger

“…However, the preliminary results of this study suggest that with further refinement, HSI combined with chemometric data processing may be used to estimate the concentrations of desirable pungent constituents in dried ginger powder, which could be greatly beneficial for quality assurance purposes. As 6-shogaol is approximately twice as pungent as 6-gingerol [ 11 ], dried ginger samples with a lower gingerol:shogaol ratio would be expected to have a more pungent flavour. Conversely, those with a higher gingerol:shogaol ratio would have a milder flavour.…”

“…The most abundant pungent constituent present in fresh ginger is 6-gingerol, which possesses an alkyl side chain length of 6 carbons [ 9 ]. Under heat treatment, 6-gingerol undergoes an elimination dehydration reaction to form 6-shogaol [ 10 ], which is more pungent than 6-gingerol [ 11 ] and displays greater bioactivity [ 12 ]. The structures of these compounds are shown in Figure 1 .…”