• Journal of Life Science
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• v.28 no.10
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• pp.1163-1169
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• 2018

In order to utilize the residue that is thrown away after an onion harvest, we analyzed the physiological activity and cytotoxicity of fermented and hot water extracts of the residue. The pH of the extracts were all acidic, and organic matter content was 0.75% in the fermented extract and four times more than 0.19% in the hot water extract. The contents of nitrogen, phosphoric acid, calcium, and magnesium components, except for the potassium component among macroelements, were higher in the fermented extract than in the hot water extract. The content of iron and silicon among the micro-elements was also higher in the fermented extract than in the hot water extract. In addition, the content of boron was higher in the hot water extract than in the fermented extract. The total polyphenol contents of the fermented and hot water extracts were $16.2{\pm}3.3mg{\cdot}g^{-1}$ and $14.6{\pm}1.4mg{\cdot}g^{-1}$, respectively, which was $1.6mg{\cdot}g^{-1}$ higher in the fermented extract than in the hot water extract. However, the total flavonoid contents of the fermented and hot water extracts were $0.1{\pm}0.1mg{\cdot}g^{-1}$ and $4.8{\pm}0.7mg{\cdot}g^{-1}$, respectively, which was $4.7mg{\cdot}g^{-1}$ higher in the hot water extract than in the fermented extract. DPPH and ABTS radical scavenging ability for antioxidant activity were higher in the hot water extract than the fermented extract. The cytotoxicity of the extract using MTT assay showed cell viability of 101.6% and 97.9% in the fermented and hot water extracts, respectively. It was confirmed that there was no cytotoxicity in either extract.