El-Shora Hamed M, Abo-Elmaaty Sabah A, El-Sayyad Gharieb S, Al-Bishri Widad M, El-Batal Ahmed I, Hassan Mervat G
Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt.
Botany and Microbiology Department, Faculty of Science, Benha University, Benha, Egypt.
Microb Cell Fact. 2025 Jan 4;24(1):5. doi: 10.1186/s12934-024-02603-x.
Because the process is cost-effective, microbial pectinase is used in juice clearing. The isolation, immobilization, and characterization of pectinase from Aspergillus nidulans (Eidam) G. Winter (AUMC No. 7147) were therefore the focus of the current investigation.
Ammonium sulphate (85%), DEAE-cellulose, and Sephadex G-200 were used to purify the enzyme. With a yield of 30.4%, the final specific activity was 400 units mg protein and 125-fold purification. Using SDS-PAGE to validate the purification of the pectinase, a single band showing the homogeneity of the purified pectinase with a molecular weight of 50 kD was found. Chitosan and calcium alginate both effectively immobilized pectinase, with immobilization efficiencies of 85.7 and 69.4%, respectively. At 50, 55, 60, and 65 °C, the thermostability of both free and chitosan-immobilized pectinase was examined. The free and chitosan-immobilized enzymes had half-lives (t) of 23.83 and 28.64 min at 65 °C, and their K values were 0.0291 and 0.0242 min, respectively. In addition, the Z values were 44.6 and 31.54 °C, while the D values were 79.2 and 95.1 min. Compared to the untreated one, the orange, mango, and pineapple juices treated with immobilized pure pectinase showed greater clarity. Following treatment with pure pectinase, the fruit juice's 1, 1-diphenyl-2-picrylhydrazyl and 2, 2'-azino-bis 3-ethylbenzothiazoline-6-sulfonate scavenging activities increased. Following treatment with pure pectinase, the amounts of total phenolics and total flavonoids increased.
The procedure is deemed cost-effective in the food industry because the strong affinity of fungal pectinase for pectin. The investigated pectinase supported its usage in the food industry by being able to clear orange, mango, and pineapple juices.
由于该工艺具有成本效益,微生物果胶酶被用于果汁澄清。因此,本研究的重点是从构巢曲霉(Eidam)G. Winter(AUMC编号7147)中分离、固定化和表征果胶酶。
使用硫酸铵(85%)、DEAE-纤维素和Sephadex G-200对酶进行纯化。最终比活性为400单位/毫克蛋白质,纯化倍数为125倍,产率为30.4%。使用SDS-PAGE验证果胶酶的纯化,发现一条单一的条带,表明纯化的果胶酶具有均一性,分子量为50 kDa。壳聚糖和海藻酸钙都能有效地固定化果胶酶,固定化效率分别为85.7%和69.4%。在50、55、60和65℃下,研究了游离和壳聚糖固定化果胶酶的热稳定性。游离和壳聚糖固定化酶在65℃下的半衰期(t)分别为23.83和28.64分钟,其K值分别为0.0291和0.0242分钟。此外,Z值分别为44.6和31.54℃,D值分别为79.2和95.1分钟。与未处理的果汁相比,用固定化纯果胶酶处理的橙汁、芒果汁和菠萝汁更澄清。用纯果胶酶处理后,果汁的1,1-二苯基-2-苦基肼和2,2'-偶氮双(3-乙基苯并噻唑啉-6-磺酸)清除活性增加。用纯果胶酶处理后,总酚和总黄酮的含量增加。
该方法在食品工业中被认为具有成本效益,因为真菌果胶酶对果胶具有很强的亲和力。所研究的果胶酶能够澄清橙汁、芒果汁和菠萝汁,支持其在食品工业中的应用。