单 位：
中粮营养健康研究院有限公司品牌食品研发中心;哈尔滨工业大学化工与化学学院;中国农业大学食品科学与营养工程学院
关键词：
胡萝卜素;乳状液;α-乳白蛋白;表没食子儿茶素没食子酸酯(EGCG);稳定性
摘 要：
以β-胡萝卜素为芯材,利用α-乳白蛋白(α-LA)为乳化剂制备了不同p H值的乳液,并利用表没食子儿茶素没食子酸酯(EGCG)作为抗氧化剂添加到乳液中,测定了乳液的粒径、电位、包埋率、快速稳定性、界面蛋白含量,考察了p H值和EGCG添加量对β-胡萝卜素乳液物理稳定性的影响,并对稳定性机理进行了研究。结果表明:EGCG添加量对p H值2. 0和p H值7. 0的乳液粒径、电位和包埋率没有显著影响(p> 0. 05),但对不同p H值乳液的快速稳定性影响显著(p <0. 05)。在p H值2. 0的乳液中,当EGCG添加量大于0. 2%时,随着EGCG添加量的增加,乳液稳定性下降;在p H值7. 0的乳液中,当EGCG添加量小于0. 02%时,乳液的稳定性比未添加EGCG的乳液稳定性高;当EGCG添加量在0. 02%～0. 10%时,随着EGCG添加量的增大,乳液稳定性降低。当EGCG添加量大于0. 10%时,EGCG的添加使β-胡萝卜素乳液快速分层,不能得到稳定乳液,原因是EGCG可以与α-LA相互作用使α-LA沉淀,致使没有足够的α-LA作为乳化剂稳定乳液。
译 名：
Effect of EGCG on Physical Stability of β-carotene Encapsulated in Oil-in-water Emulsions
作 者：
LIU Lei;CHEN Lishui;MA Ying;GAO Yanxiang;Brand Food R&D Center,COFCO Nutritionand Health Research Institution;School of Chemistry and Chemical Engineering,Harbin Institute of Technology;College of Food Science and Nutritional Engineering,China Agricultural University;
单 位：
LIU Lei%CHEN Lishui%MA Ying%GAO Yanxiang%Brand Food R&D Center,COFCO Nutritionand Health Research Institution%School of Chemistry and Chemical Engineering,Harbin Institute of Technology%College of Food Science and Nutritional Engineering,China Agricultural University
关键词：
β-carotene;;emulsion;;α-lactalbumin;;(-)-epigallocatechin-3-gallate;;stability
摘 要：
Carotene is used in food industry as a precursor of vitamin A with potent antioxidant activity through singlet oxygen quenching and deactivation of free radicals. Nevertheless,their utilization as nutraceutical ingredients in food industry is currently limited because of their poor water-solubility,high melting point,chemical instability and low bioavailability. Emulsion-based systems are often a better choice for delivering bioactive lipids such as β-carotene into functional foods since the emulsion increases bioavailability. The physical properties of β-carotene emulsions were characterized,which were stabilized by α-lactalbumin( α-LA) at different pH values with(-)-epigallocatechin-3-gallate( EGCG) as antioxidant. The particle size,zeta-potential,encapsulation rate,stability index and interfacial protein of the emulsions were measured. EGCG addition had no effect on particle size, zeta-potential and encapsulation rate of the emulsions,however,the addition of EGCG significantly influenced the physical stability of the emulsions. When the addition of EGCG was higher than 0. 2% in the emulsions at pH value of 2. 0,the physical stability was decreased with the increase of addition. The stability of emulsions at pH value of 7. 0 was improved by the addition of EGCG in the range of 0. 002 5% ～ 0. 020 0%,however,the stability of the emulsions was decreased when the EGCG addition was within 0. 02% ～0. 10%. When the addition of EGCG was higher than 0. 10%,the emulsions were separated into two phases quickly. In the mechanism study,the presence of EGCG changed the size and turbidity in α-LA solution when the addition was above 0. 05%. Isothermal titration calorimetry( ITC) analysis implied that EGCG can interact with α-LA,with about five EGCG molecules integrated with one α-LA molecule. β-carotene emulsions destabilized by EGCG addition( greater than 0. 10%) may due to the interaction between EGCG and α-LA.
