Preparation of bamboo leaf hydrosols by the steam-distillation extraction process

Abstract

The best extraction characteristics and optimal parameters for the steam-distillation extraction of bamboo leaf hydrosols were investigated to provide a data foundation for the subsequent study of bamboo leaf hydrosols and their industrial applications. The colligation score (CS) of the bamboo leaf hydrosols antioxidant activity (based on its DPPH free radical scavenging ability and total antioxidant capacity) was used as an evaluation index. The extraction time, crushing degree, and solid-to-liquid ratio were selected as the extraction parameters and response surface methodology was used to optimize the extraction process. The CS and sensory evaluation were used to determine the best distilled volume of bamboo leaf hydrosols. The results showed that the prepared bamboo leaf hydrosols had a high CS of 0.9967 (the DPPH free radical scavenging capacity was 0.052 mg/mL Vc equivalent, and the total antioxidant capacity was 0.2771 mg/mL Trolox equivalent) when the bamboo leaf crushing degree was 10 mesh, the solid-to-liquid ratio was 1:25, and the extraction time was 6 h. When the distilled volume was one-quarter of the total aqueous extract volume, the bamboo leaf hydrosols were highly active, colorless, and had a pleasantly aromatic odor.