Shi Xuerong, Yang Xuzhong, He Shaotong, Duan Ting, Liang Xin, Ma Shuzhen, Gong Jijun
College of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China.
Hunan Key Laboratory of Forestry Edible Sources Safety and Processing, Hunan Key Laboratory of Processed Food for Special Medical Purpose, Changsha 410004, China.
Foods. 2024 Nov 22;13(23):3737. doi: 10.3390/foods13233737.
This study explored the kinetics of ultrasonic extraction of polysaccharides (LP) from leaf (L), evaluated the in vitro bioactivity of L extracts and LP, and characterized the LP. A kinetic model was developed based on Fick's second law. A technique utilizing 400 W for 50 min was employed for the ultrasonic extraction of LP, with an optimal solid-liquid ratio established at 1:40 (g/mL). L extracts dried using different methods exhibited varying antioxidant activity and inhibitory effects against α-amylase and α-glucosidase. An in vitro study revealed that L extracts obtained through vacuum freeze drying demonstrated significantly stronger antioxidant activity, while those derived through microwave drying showed superior inhibitory effects against α-amylase and α-glucosidase compared to the other two drying methods. Furthermore, it was observed that the in vitro bioactivity of LP (purity: 74.07 ± 0.52%) was significantly lower than that of L extracts. Nevertheless, LP (5.0 mg/mL) demonstrated a scavenging ability reaching 64.86% of VC for DPPH radical and 67.14% of VC for ·OH radical, and the inhibition of LP (10 mg/mL) on α-amylase and α-glucosidase reached 58.40% and 38.28% of the acarbose, respectively. The findings revealed that LP are predominantly composed of mannose, glucose, galactose, and arabinose in a distinctive molar ratio of 89.00:16.33:4.78:1.
本研究探究了从叶片（L）中超声提取多糖（LP）的动力学，评估了L提取物和LP的体外生物活性，并对LP进行了表征。基于菲克第二定律建立了动力学模型。采用400 W功率超声提取50 min的技术提取LP，确定最佳固液比为1:40（g/mL）。采用不同方法干燥的L提取物表现出不同的抗氧化活性以及对α-淀粉酶和α-葡萄糖苷酶的抑制作用。一项体外研究表明，通过真空冷冻干燥获得的L提取物具有显著更强的抗氧化活性，而通过微波干燥获得的提取物对α-淀粉酶和α-葡萄糖苷酶的抑制作用优于其他两种干燥方法。此外，观察到LP（纯度：74.07±0.52%）的体外生物活性显著低于L提取物。然而，LP（5.0 mg/mL）对DPPH自由基的清除能力达到了VC的64.86%，对·OH自由基的清除能力达到了VC的67.14%，LP（10 mg/mL）对α-淀粉酶和α-葡萄糖苷酶的抑制作用分别达到了阿卡波糖的58.40%和38.28%。研究结果表明，LP主要由甘露糖、葡萄糖、半乳糖和阿拉伯糖组成，其独特的摩尔比为89.00:16.33:4.78:1。
