超临界体系热致番茄红素顺式异构化及其抗氧化活性评价

Thermal Z-isomerization of lycopene in supercritical system and evaluation of its antioxidant activity

番茄红素是一种重要的具有强抗氧化活性、降低多种慢性疾病发病风险功效的类胡萝卜素。为提高全反式番茄红素的脂溶性、生物利用度和生物活性,利用绿色化学技术,在超临界CO_(2)-乙醇体系中通过热致异构化法制得高顺式异构体占比的番茄红素。以总顺式番茄红素占比为评价指标,经单因素试验和响应面试验条件优化,得到最佳的制备工艺条件为:番茄红素含量2.0 mg/mL(基于乙醇体积)、反应温度100℃、反应时间52 min、反应压力33 MPa,该条件下总顺式番茄红素异构体占比可达到61.6%。采用DPPH法和ABTS法,分别对原料和异构化产品的抗氧化能力进行比较研究,结果表明,经顺式异构化反应后可提高原料番茄红素的抗氧化活性。该绿色工艺法可实现高顺式占比番茄红素异构体的高效制备,以期为其工业化生产提供理论借鉴,从而有望将其应用到食品添加剂、食品配料及功能性食品等领域。

Lycopene is an important carotenoid with strong antioxidant activity and the ability of reducing the risk of many chronic diseases.In order to improve the lipid solubility,bioavailability,and biological activity of all-trans-lycopene,lycopene with a high cis-isomer ratio was prepared by thermal isomerization in a supercritical CO_(2)-ethanol system using green chemical technology.Taking the proportion of total cis-lycopene as the evaluation index,further optimization of preparation conditions was carried out through single factor test and response surface test,the optimal preparation conditions were as follows:lycopene content 2.0 mg/mL(based on the volume of ethanol),reaction temperature 100℃,reaction time 52 min,and reaction pressure 33 MPa.Under these conditions,the proportion of total cis-lycopene isomers could reach 61.6%.The DPPH method and ABTS method were used to compare the antioxidant activity of raw materials and isomerized products respectively.The results showed that the antioxidant activity of lycopene could be improved by cis-isomerization.This green process method can realize the efficient preparation of lycopene isomers with a high cis-ratio,thus providing a theoretical reference for their industrial production,lycopene isomers with a high cis-ratio are expected to be applied to food additives,food ingredients,functional food,and other fields.