Phytochemical properties and functional characteristics of wild turmeric ( Curcuma aromatica) fermented with Rhizopus oligosporus

Highlights

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  Wild turmeric ( Curcuma aromatica) was fermented with R. oligosporus.

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  Curcuminoid fermented for 5 days and phenolic compound of all fermented wild turmeric increased.

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  The l-carnitine content of fermented wild turmeric was newly synthesized.

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  The antioxidant activities were enhanced 1.47-fold after fermentation for 3 days.

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  Anti-inflammatory, anti-melanogenic, and anti-obesity effects improved with fermentation .

Abstract

This study investigated the effect of solid-state fermentation of wild turmeric ( Curcuma aromatica) with Rhizopus oligosporus, a common fungus found in fermented soy tempeh, on phytochemical and biological properties. Ultra-performance liquid chromatography–tandem mass spectrometry showed that fermented wild turmeric has higher concentrations of curcumin, demethoxycurcumin, bisdemethoxycurcumin, phenolic compounds and total flavonoid-curcuminoid after fermentation for 1-, 3-, and 5-day relative to non-fermented turmeric. The l-carnitine content reached 242 µg g ⁻¹ extract after fermentation for 7-day. Wild turmeric had 1.47- and 2.25-fold increases in ORAC and FRAP, respectively, after 3-day fermentation. The inhibitory effects of fermented wild turmeric on lipid accumulation from 3T3-L1 cells, nitric oxide production from lipopolysaccharide-stimulated RAW264.7 murine macrophages, and melanin formation by B16F10 mouse melanoma cells with α-MSH increased 1.08-, 1.44-, and 1.52-fold, respectively, after 3-day fermentation. Based on these results, fermented wild turmeric product can be used as a functional ingredient in the cosmeceutical and nutraceutical industries.