玉米植物糖原超声辅助提取工艺优化及其生物活性评价

Optimization of Ultrasound-assisted Extraction of Phytoglycogen from Sweet Corn and Its Bioactivity Evaluation

本文主要探究超声辅助法从甜玉米中提取植物糖原(phytoglycogen,PG)的最佳工艺并对其理化性质和生物活性进行初步评价。该实验以PG的得率为指标,考查固液比、超声功率和超声时间对PG得率的影响,并利用正交试验优化工艺参数。在此基础上,研究了超声辅助法制备得到的PG的理化性能,并开展PG的体外抗氧化、细胞毒性、凋亡以及溶血评价。结果表明:正交试验优化后得到最佳工艺为固液比1:9(g/mL)、超声功率160 W、超声时间80 min,在此条件下实际得率为14.31%±0.38%;表征结果显示超声辅助法获取的PG颗粒尺寸低于传统水提醇沉法;体外抗氧化实验表明PG具有一定的抗氧化能力,尤其是对DPPH自由基更为敏感,在20 mg/mL时清除率达到54.58%±1.39%;生物安全性评价结果显示不同浓度的PG在与小鼠成纤维细胞(3T3)孵育24或48 h后,细胞存活率均高于95%;同时,PG也没有对细胞产生明显的凋亡效应,在最大浓度时,凋亡率低于7%;此外,在共孵育2 h后,PG对红细胞造成的溶血率也远低于国家标准(5%),这些结果证实了PG对正常细胞和红细胞均有良好的生物相容性。总体上,本研究表明超声辅助法有助于提高PG的得率和理化性能,同时,也证实了PG是一种无毒的天然纳米颗粒,在药物或食品因子递送方面具有较大的应用潜力。

The optimal extraction process of phytoglycogen(PG)from sweet corn by ultrasound-assisted method was studied,and the physicochemical properties and biological activities of PG were evaluated in this paper.The effects of solid-liquid ratio,ultrasonic power and ultrasonic time on the yield of PG were investigated and the process parameters were further optimized by orthogonal experiment.Furthermore,the physicochemical properties of PG obtained by ultrasound-assisted method were investigated.Meanwhile,the antioxidation,cytotoxicity,apoptosis and hemolysis of PG were evaluated in vitro.The results showed that the optimal extraction conditions were as follows:Solid-liquid ratio of 1:9(g/mL),ultrasonic power of 160 W and ultrasonic time of 80 min,the actual yield was 14.31%±0.38%.The PG particle size obtained by ultrasound-assisted method was lower than that obtained by traditional water extraction and alcohol precipitation method.In vitro antioxidant experiment showed that PG had a certain antioxidant capacity,especially it was more sensitive to DPPH free radicals,and the clearance rate reached 54.58%±1.39%at 20 mg/mL.The results of biosafety evaluation showed that the survival rate of mouse fibroblasts(3T3)was higher than 95%after incubation with different concentrations of PG for 24 or 48 h.Meanwhile,PG had no obvious apoptotic effect on cells,and the apoptotic rate was lower than 7%at the maximum concentration.After 2 h of co-incubation,the hemolysis rate caused by PG on red blood cells was also much lower than the national standard(5%),which confirmed that PG had good biocompatibility with normal cells and red blood cells.Overall,this study showed that ultrasound-assisted method could improve the yield and physicochemical properties of PG,and also confirmed that PG was a non-toxic natural nanoparticle,which had great application potential in drug or food factor delivery.