Singhania Tripti, Sinha Harsh, Das Paulomi, Mukherjee Amit Kumar
Department of Food Technology, Haldia Institute of Technology, P. O. HIT, Hatiberia, Purba Medinipur, 721657 Haldia, West Bengal, India.
Food Technol Biotechnol. 2015 Mar;53(1):91-95. doi: 10.17113/ftb.53.01.15.3740.
Phospholipase A (PLA) immobilized in calcium alginate can effectively overcome the mass transfer resistance at the lipid-water interface making more room for the enzyme to separate itself from the products of reaction and to bind with the next available molecule at the interface. The reaction of an immobilized PLA hydrolase from was comparatively faster than of its free form. The rate of phospholipid hydrolysis by PLA was studied in calcium-rich and calcium-depleted environments; and the extent of phosphorus removed from the crude rice bran oil as well as the amount of free fatty acids produced during the reaction were used as indices for analysing the rate of enzymatic hydrolysis under standard conditions of pH, temperature, time of incubation and agitation. The immobilized PLA was found to be superior in removing phosphorus in the presence of 10 mM bivalent calcium ions in a solution. As compared to a maximum of 72.52% phosphorus removed by 0.01 kg of free enzyme per kg of oil, the same amount of immobilized PLA removed phosphorus from oil by 94.12% under the same experimental conditions (pH=6, 60 °C, 1-hour incubation). Both the free PLA and its immobilized form had shown extended rates of hydrolysis in a calcium-rich environment. The mass fractions of free fatty acids produced by the free enzyme and by its immobilized form were 14.9 and 14.16%, respectively, under the above experimental conditions. The removal of phosphorus from oil was accompanied by a significant reduction in colour and restoration of iodine value to the desired level.
固定在海藻酸钙中的磷脂酶A（PLA）能有效克服脂质 - 水界面处的传质阻力，为酶提供更多空间使其与反应产物分离，并与界面处下一个可用分子结合。来自[具体来源未给出]的固定化PLA水解酶的反应比其游离形式相对更快。在富含钙和贫钙环境中研究了PLA对磷脂的水解速率；在标准pH、温度、孵育时间和搅拌条件下，以从粗米糠油中去除的磷量以及反应过程中产生的游离脂肪酸量作为分析酶促水解速率的指标。发现在溶液中存在10 mM二价钙离子的情况下，固定化PLA在去除磷方面表现更优。在相同实验条件（pH = 6，60°C，孵育1小时）下，每千克油中0.01千克游离酶最多去除72.52%的磷，而相同量的固定化PLA从油中去除磷的比例为94.12%。游离PLA及其固定化形式在富含钙的环境中均表现出延长的水解速率。在上述实验条件下，游离酶及其固定化形式产生的游离脂肪酸质量分数分别为14.9%和14.16%。从油中去除磷伴随着颜色显著降低以及碘值恢复到所需水平。
