Dey Tapati Bhanja, Banerjee Rintu
Microbial Biotechnology and Downstream Processing Lab Agricultural and Food Engineering Department Indian Institute of Technology Kharagpur India ; Lignocellulose Biotechnology Laboratory Department of Microbiology University of Delhi South Campus Benito Juarez RoadNew Delhi India.
Microbial Biotechnology and Downstream Processing Lab Agricultural and Food Engineering Department Indian Institute of Technology Kharagpur India.
Braz J Microbiol. 2014 May 19;45(1):97-104. doi: 10.1590/s1517-83822014000100014. eCollection 2014.
Polygalacturonase and α-amylase play vital role in fruit juice industry. In the present study, polygalacturonase was produced by Aspergillus awamori Nakazawa MTCC 6652 utilizing apple pomace and mosambi orange (Citrus sinensis var mosambi) peels as solid substrate whereas, α-amylase was produced from A. oryzae (IFO-30103) using wheat bran by solid state fermentation (SSF) process. These carbohydrases were decolourized and purified 8.6-fold, 34.8-fold and 3.5-fold, respectively by activated charcoal powder in a single step with 65.1%, 69.8% and 60% recoveries, respectively. Apple juice was clarified by these decolourized and partially purified enzymes. In presence of 1% polygalacturonase from mosambi peels (9.87 U/mL) and 0.4% α-amylase (899 U/mL), maximum clarity (%T(660 nm) = 97.0%) of juice was attained after 2 h of incubation at 50 °C in presence of 10 mM CaCl2. Total phenolic content of juice was reduced by 19.8% after clarification, yet with slightly higher %DPPH radical scavenging property.
多聚半乳糖醛酸酶和α-淀粉酶在果汁工业中发挥着至关重要的作用。在本研究中，泡盛曲霉（Aspergillus awamori Nakazawa）MTCC 6652利用苹果渣和印度酸橙（Citrus sinensis var mosambi）果皮作为固体底物来生产多聚半乳糖醛酸酶，而米曲霉（A. oryzae）（IFO - 30103）则采用固态发酵（SSF）工艺，利用麦麸来生产α-淀粉酶。这些碳水化合物酶通过活性炭粉末在一步操作中分别进行脱色和纯化，纯化倍数分别为8.6倍、34.8倍和3.5倍，回收率分别为65.1%、69.8%和60%。这些脱色且部分纯化的酶用于澄清苹果汁。在10 mM氯化钙存在的条件下，于50℃孵育2小时后，当存在1%来自印度酸橙果皮的多聚半乳糖醛酸酶（9.87 U/mL）和0.4%的α-淀粉酶（899 U/mL）时，果汁达到了最大澄清度（%T(660 nm)=97.0%）。澄清后果汁的总酚含量降低了19.8%，但其DPPH自由基清除性能略有提高。
