Abstract:

Bamboo flavonoids exhibit potential value as food additives and preservatives due to their anti-inflammatory,antibacterial,and antioxidant properties.Here,some key parameters,including ethanol concentration,solid-to-liquid ratio,ultrasonic power,time,temperature,and organs,was systematically investigated to optimize the extraction process of Indocalamus longiauritus leaf flavonoids.We found that ethanol concentration had the most important impact on flavonoid extraction efficiency,followed by solid-to-liquid ratio,extraction time,and temperature.The optimal extraction condition was identified as 80% ethanol concentration,a 1:25 (g/mL) solid-to-liquid ratio,45 ℃ ultrasonic temperature,45 min ultrasonic time,and 300 W ultrasonic power.Among different plant organs,mature leaves showed the highest flavonoid content,followed by stems,rhizomes,and underground runners,while unopened leaves had the lowest content.Furthermore,seasonal variations in flavonoid content were observed,with a decreasing trend in the first half of the year and an increasing trend in the second half,peaking in November as the optimal harvest time.This study provides theoretical and practical foundations for the extraction and industrial application of bamboo leaf flavonoids.

Key words: Bambusoideae, Indocalamus longiauritus, flavonoid, resource utilization, ultrasound-assisted extraction, process optimization