使用壳聚糖 MNPs 共固定化酶对葡萄柚汁进行一锅澄清和脱苦。
One pot clarification and debittering of grapefruit juice using co-immobilized enzymes@chitosanMNPs.
机构信息
Department of Chemical Engineering, Institute of Chemical Technology, Mumbai, India.
Department of E&TC, J.L.Chaturvedi College of Engineering & Technology, Nagpur, India.
出版信息
Int J Biol Macromol. 2021 Jan 15;167:1297-1307. doi: 10.1016/j.ijbiomac.2020.11.084. Epub 2020 Nov 14.
In the present work, enzymes pectinase and naringinase were simultaneously co-immobilized on an eco-friendly chitosan coated magnetic nanoparticles (chitosanMNPs) by cross-linking using chitosan as a macro-molecular cross-linker. The maximum activity recovery of both enzymes in the co-immobilized form was obtained at chitosanMNPs to enzymes ratio of 1:3, 3% cross-linker concentration and 150 min cross-linking time. The synthesized MNPs before and after co-immobilization were characterized using different techniques. The prepared biocatalyst was found spherical with an average size below 200 nm and showed supermagnetic property with saturation magnetization of 38.28 emu/g. The optimum pH and temperature of both enzymes in co-immobilized form was found at 5.5 and 65 °C. The prepared biocatalyst exhibited an improved thermal stability with 1.8-fold increase in the half-life. The secondary structural analysis revealed that, prepared co-immobilized biocatalyst undergone changes in the conformational and structural rigidity due to macro-molecular cross-linker. The co-immobilized biocatalysts were evaluated for one pot clarification and debittering of grapefruit juice and found ~52% reduction in turbidity and ~85% reduction in the naringin content. The co-immobilized enzymes were recycled up to 7 cycle and can be easily stored at room temperature for 30 days retaining up to 64% and 86% residual activities respectively.
在本工作中,通过使用壳聚糖作为大分子量交联剂进行交联,将果胶酶和柚皮苷酶同时共固定在环保的壳聚糖涂覆的磁性纳米颗粒(壳聚糖 MNPs)上。在壳聚糖 MNPs 与酶的比例为 1:3、3%交联剂浓度和 150 min 交联时间时,获得了共固定化形式中两种酶的最大活性回收率。在共固定化前后使用不同的技术对合成的 MNPs 进行了表征。所制备的 MNPs 呈球形,平均粒径小于 200nm,并具有超顺磁性,饱和磁化强度为 38.28 emu/g。共固定化形式中两种酶的最佳 pH 和温度分别为 5.5 和 65°C。所制备的生物催化剂表现出改善的热稳定性,半衰期增加了 1.8 倍。二级结构分析表明,由于大分子量交联剂,制备的共固定化生物催化剂的构象和结构刚性发生了变化。共固定化生物催化剂用于一步法澄清和脱苦葡萄柚汁,发现浊度降低了约 52%,柚皮苷含量降低了约 85%。共固定化酶可回收 7 个循环,可在室温下轻松储存 30 天,分别保留 64%和 86%的剩余活性。