Phenolics, Flavonoids Content and Antioxidant Activities of Tuber indicum at Different Maturity Stages

The Chinese black truffle Tuber indicum (Ascomycota, Pezizales) is an ectomycorrhizal fungus forming hypogeous edible ascocarps. As a famous wild edible mushroom in the world, this species also attracted an increasing interest in their chemical composition and pharmacological activity. In this study, the total phenolic content, total flavonoid content and antioxidant activities of Tuber indicum collected from July to November at different maturity stages in China were analyzed. Our results showed that T. indicum collected in July (immature stage) possessed the highest amount of flavonoids (3.89 mg/g dw) and the highest ABTS^.+ scavenging activity (EC₅₀ =3.73 mg/ml). In addition, those samples collected in August (moderate mature stage) contained the highest phenolics content (4.78 mg/g dw), the highest DPPH⋅ radical scavenging activity (EC₅₀ =3.73 mg/ml) and ferric reducing activity power (243.63 μmol FeSO₄ /g). The study reveals T. indicum in the early maturity stage yield significantly higher content of phenolics and flavonoids and possessed stronger antioxidant activity than those collected in other months. This study provided important data for understanding the relationship between maturity stages and truffle formation and evaluating the quality of Chinese black truffle at different maturity.