Department of Biotechnology, Rajalakshmi Engineering College, Thandalam, Chennai-602 105, Tamil Nadu, India.
J Agric Food Chem. 2013 Jun 5;61(22):5385-90. doi: 10.1021/jf4009789. Epub 2013 May 24.
Enzymatic browning by polyphenoloxidase (PPO) affects food quality and taste in fruits and vegetables. Thus, the study was designed to reduce browning in apple juice by coumarin. The ethanolic extract of cinnamon was prepared and its coumarin content was quantitated by HPLC, using authentic coumarin (AC) as standard. The effect of cinnamon extract (CE) and AC on enzymatic browning, its time dependent effects, and the specific activity of PPO and peroxidase (POD) were studied in apple juice. The docking of coumarin with PPO and POD was also performed to elucidate its antibrowning mechanism. The CE (73%) and AC (82%) showed better reduction in browning, maintained its antibrowning effect at all time points, and significantly (p < 0.05) reduced the specific activity of PPO and POD when compared with controls. Coumarin showed strong interaction with binding pockets of PPO and POD, suggesting its potential use as inhibitor to enzyme mediated browning in apple juice.
多酚氧化酶（PPO）引起的酶促褐变会影响水果和蔬菜的食品质量和口感。因此，本研究旨在通过香豆素降低苹果汁的褐变。用高效液相色谱法（HPLC）制备肉桂的乙醇提取物，并以真实香豆素（AC）为标准定量其香豆素含量。研究了肉桂提取物（CE）和 AC 对苹果汁中酶促褐变的影响、其时间依赖性效应以及 PPO 和过氧化物酶（POD）的比活性。还进行了香豆素与 PPO 和 POD 的对接，以阐明其抗褐变机制。CE（73%）和 AC（82%）在降低褐变方面表现更好，在所有时间点都保持其抗褐变效果，并且与对照组相比，显著（p < 0.05）降低了 PPO 和 POD 的比活性。香豆素与 PPO 和 POD 的结合口袋表现出强烈的相互作用，表明其可能作为抑制剂用于苹果汁中酶介导的褐变。
