摘要
全蛋液富含蛋白质、脂肪及多种维生素和矿物质,是一种天然的营养补充来源,但高含量的磷限制了其在肾病患者饮食中的应用。选取活性炭、水滑石、硅藻土对全蛋液进行脱磷处理,以脱磷率、蛋白质损失率和色差变化为指标,优化吸附剂添加量、吸附时间和吸附温度,并对3种吸附剂在全蛋液中磷吸附的吸附等温式、吸附动力学及吸附热力学进行拟合。结果表明:活性炭的优化添加量为8 g/L,吸附时间为120 min,吸附温度为35℃;水滑石的优化添加量为8 g/L,吸附时间为150 min,吸附温度为35℃;硅藻土的优化添加量为8 g/L,吸附时间为90 min,吸附温度为35℃。在吸附过程中,水滑石造成的蛋白质损失最小,对磷酸基团的吸附专一性最高;活性炭对a*值的影响最大,硅藻土对b*值影响最大,3种吸附剂均造成L*值的增加。对吸附机理的研究表明:水滑石多以单分子层形式吸附,3种吸附剂的Freundlich吸附等温式n值均大于1。随着吸附温度的增加,活性炭、水滑石和硅藻土的KF均逐渐增大。3种吸附剂的准一级动力学模型R2均较低,并且随着温度的增加呈现波动变化;硅藻土的准二级动力学模型R2较高,化学吸附程度较高。活性炭、水滑石和硅藻土的ΔG均为负值、ΔH均大于0,即反应自发进行且为吸热反应。
Whole egg liquid is rich in protein,fat,and many kinds of vitamins and minerals.It is a natural source of nutritional supplements,but high level of phosphorus limits its use in the diet of patients with kidney disease.Activated carbon,hydrotalcite and diatomite were selected to dephosphorize the whole egg liquid.The dephosphorization rate,protein loss rate and color difference changes were taken as the indexes,the optimum amount of adsorbent,adsorption time and adsorption temperature were optimized,and then,the adsorption isotherms,adsorption kinetics and adsorption thermodynamics of phosphorus adsorption by three adsorbents in the whole egg liquid were fitted.The results showed that the optimum dosage of activated carbon was 8 g/L,adsorption time was 120 min and adsorption temperature was 35℃,while the optimum dosage of hydrotalcite was 8 g/L,adsorption time was 150 min and adsorption temperature was 35℃,and the optimum dosage of diatomite was 8 g/L,the adsorption time was 90 min and the adsorption temperature was 35℃.In the process of adsorption,hydrotalcite led to the least loss of protein and the highest adsorption specificity for phosphate groups.Activated carbon had the greatest effect on a*,diatomite had the greatest effect on b*,and all three adsorbents increased L*.The study of adsorption mechanism showed that diatomite was adsorbed in the form of monolayer,and n value of Freundlich adsorption isotherm of three adsorbents were all greater than 1.With the increase of adsorption temperature,the K F of activated carbon,hydrotalcite and diatomite increased gradually.The quasi-first-order kinetic model R 2 of three adsorbents were lower,and fluctuated with the increase of temperature.The quasi-second-order kinetic model R 2 of diatomite was higher,and the chemical adsorption degree of diatomite was higher.TheΔG of activated carbon,hydrotalcite and diatomite were all negative and theΔH were greater than 0,which meant that the reaction was spontaneous and endothermic.
作者
马艳秋
张佳佳
何晶
迟玉杰
MA Yanqiu;ZHANG Jiajia;HE Jing;CHI Yujie(College of Food Science,Northeast Agricultural University,Harbin 150030,China)
出处
《食品科学技术学报》
EI
CAS
CSCD
北大核心
2023年第3期163-174,共12页
Journal of Food Science and Technology
基金
黑龙江省重点研发计划项目(GA21B008)
现代农业产业技术体系建设专项(CARS-40-K25)。
关键词
全蛋液
磷酸基团
活性炭
水滑石
硅藻土
吸附模型
whole egg liquid
phosphate group
activated carbon
hydrotalcite
diatomite
adsorption model
