L-抗坏血酸辛酸酯的酶法合成及性质研究  

Research on Enzymatic Synthesis and Property of L-Ascorbyl Octanoate

作　　者：张淑青[1] 操丽丽[1] 吴学凤[1] 莫玉稳 潘丽军[1] 

机构地区：[1]合肥工业大学生物与食品工程学院安徽省农产品精深加工重点实验室,合肥230009

出　　处：《中国粮油学报》2016年第7期107-113,共7页Journal of the Chinese Cereals and Oils Association

基　　金："十一五"国家科技支撑计划(2010BAD01B07);农业科技成果转化资金项目(2013GB2C300217)

摘　　要：在叔丁醇体系中,Novozym 435固定化脂肪酶催化L-抗坏血酸和中链脂肪酸正辛酸发生酯化反应合成L-抗坏血酸辛酸酯(L-AO),在底物(L-抗坏血酸)浓度0.2 mol/L、底物摩尔比6:1、脂肪酶用量20%、反应温度55℃、分子筛添加量60 mg/mL条件下反应12 h,L-抗坏血酸酯化转化率可达85.6%。DSC分析结果表明L-AO具有较低的结晶温度和较高的结晶焓,使其在低温时不易结晶析出。油溶性测定结果显示,L-AO在植物油中的溶解度远远大于L-抗坏血酸棕榈酸酯(L-AP),较高的油溶性有利于扩展其在油脂及脂溶性产品中的应用。羟自由基清除能力以及对油脂的抗氧化性能试验结果表明L-AO具有较强的抗氧化能力,是一种很有潜力的油溶性抗氧化剂。The esterification of n - octanoic acid with L - ascorbic acid and medium - chain fatty acid n - ca- prylic acidin the presence of immobilized lipase（ Novozym 435 ） as the catalyst and tert -butanol as the solvent to ob- tain L- ascorbyl octanoate（L- AO） was studied. The conversion rate ofL- ascorbic acid could reach 85.6% under the conditions of concentration of L - ascorbic acid 0.2 mol/L, substrate molar ratio 6： 1, enzyme dosage 20%, reac- tion temperature 55 ℃, molecular sieve dosage 60 mg/mL and reaction time 12 h. DSC analysis results indicated that L - AO has lower crystallization temperature and higher crystal enthalpy, which make it not easily to crystallize out at low temperatures. And the oil solubility analysis resluts indicated that the solubilities of L -AO in the vegetable oils are far greater than that of L -ascorbic palmitate （L -AP）, the higher oil -solubility of L -AO benefits to extend its application in oils and fat - soluble products. The antioxidant activities of L - AO were studied by hydroxyl radical system and further evaluated by adding into the soybean oil. The hydroxyl radical scavenging activity and oxidation resistence test results of grease indicated that L - AO had strong oxidation resistance and L - AO was demonstrated to be a potential oil -soluble antioxidants.

关 键 词：正辛酸 L-抗坏血酸脂肪酶 L-抗坏血酸辛酸酯DSC 油溶性 抗氧化活性 

分 类 号：TS202.3[轻工技术与工程—食品科学]