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。
β-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 asβ-carotene into functional foods since the emulsion increases bioavailability.The physical properties ofβ-carotene emulsions were characterized,which were stabilized byα-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 inα-LA solution when the addition was above 0.05%.Isothermal titration calorimetry(ITC)analysis implied that EGCG can interact withα-LA,with about five EGCG molecules integrated with oneα-LA molecule.β-carotene emulsions destabilized by EGCG addition(greater than 0.10%)may due to the interaction between EGCG andα-LA.
作者
刘蕾
陈历水
马莺
高彦祥
LIU Lei;CHEN Lishui;MA Ying;GAO Yanxiang(Brand Food R&D Center,COFCO Nutritionand Health Research Institution,Beijing 102209,China;School of Chemistry and Chemical Engineering,Harbin Institute of Technology,Harbin 150090,China;College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100083,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第2期340-349,共10页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金面上项目(31371835)
