Chemical and Microbial Quality of Irradiated Ground Ginger

Abstract

Fresh ground ginger was irradiated with a IO-kGy ionizing radiation dose from a Cobalt-60 source. Gamma radiation decreased most of the extractable volatile flavor components. Those known to contribute to typical ginger flavor, e.g., zingiberene, P-sesquiphellandrene, P-bisabolene, famesene isomers, arcurcumene, and a-cubebene, decreased 27-59% following irradiation. Most odors recognized through gas chromatography/olfactometry produced similar patterns from irradiated and nonirradiated samples. The radiation treatment reduced the aerobic microbial population from lo8 to 10' CFU/g. Sensory qualities of flavor, color and odor of ginger powder were similar for treated and untreated ginger.

Analysis of electron spin resonance spectra of irradiated gingers: Organic radical components derived from carbohydrates

“…The annual quantity of imported ginger exceeds that of all other spices in Japan (Trade Statistics of Japan, 2008). The volatile oil constituent or quality of ginger irradiated with gamma or electron beam (EB), to inhibit sprouting or kill microorganisms, has been reported to be similar for un-irradiated ginger (Andrews et al, 1995;Wu and Yang, 1994). Furthermore, broad and asymmetric ESR spectra have been observed in irradiated ginger (Duliu et al, 2007;Kubo et al, 2001), similar to the spectra of irradiated dry fruits (Esteves et al, 1999).…”

Effects of drying on flavour compounds in Australian-grown ginger (Zingiber officinale)

“…These last compounds are chromatographic decomposition products of gingerols. 17,19 This fact can be established by the injection of a pure sample of 6-gingerol onto the column under the same conditions as used for the analysis of the SFE samples (Fig 1(b)). Approximately 50% of the gingerol is converted to 6-shogaol by elimination of water, while the remainder is converted by rearrangement to equimolar amounts of zingerone and hexanal.…”

Effect of Gamma and e-Beam Radiation on the Essential Oils of Thymus vulgaris thymoliferum, Eucalyptus radiata, and Lavandula angustifolia

“…Previous investigations have suggested that treatment of spices with γ-radiation doses higher than 6 kGy produces a dose- dependent reduction effect on essential oil contents, particularly in the cases of black pepper (14) and red chili pepper (15). Nevertheless, some authors have demonstrated that, at a dose of 10 kGy, dry ginger was found to be sterile without affecting its flavor quality (16). These results show that specific effects could be observed for different essential oil extracts and that the same compound present in essential oils from different plants may behave differently even if submitted to the same treatment (17).…”