Inhibition Effect of Ultrasound on the Formation of Lysinoalanine in Rapeseed Protein Isolates during pH Shift Treatment
Inhibition Effect of Ultrasound on the Formation of Lysinoalanine in Rapeseed Protein Isolates during pH Shift Treatment
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DOI：
10.1021/acs.jafc.1c02422
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发表时间：
2021-07-23
影响因子：
6.1
通讯作者：
Ma, Haile
中科院分区：
文献类型：
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作者：
Li, Yihe;Zhang, Zhaoli;Ma, Haile
pH值变化是一种有效的改变食品蛋白质功能特性的技术。但在碱性条件下会增加赖氨酸丙氨酸（LAL）含量，从而限制了蛋白质的利用。研究了pH转换处理（pH- st）过程中超声波参数对菜籽蛋白分离物（RPI） LAL形成的抑制作用。结果表明：经超声（28 kHz、40 W/L、40℃、30 min）处理后，在碱和酸条件下，LAL含量分别下降49.5%和74.1%；结构分析表明，超声辐照后，巯基和氨基酸的增加使脱氢丙氨酸减少，从而降低了LAL含量。粒度、二级结构和微观结构（SEM、AFM）分析表明，蛋白质分布相对分散，减少了分子间或分子内交联，从而降低了LAL含量。因此，超声辅助pH-ST可能是一种减少RPI中LAL形成的操作技术。
pH shift is an effective technique for modifying functional properties of food proteins. However, it can increase lysinoalanine (LAL) content under alkali conditions, thus limiting the use of proteins. This study investigated the inhibition effect of ultrasonic parameters on LAL formation in rapeseed protein isolates (RPI) during pH shift treatment (pH-ST). Results showed that the content of LAL decreased by 49.5% and 74.1%, following the use of ultrasound (28 kHz, 40 W/L, 40 degrees C, and 30 min) under alkali and acidic treatment, respectively. Structural analysis showed that after ultrasonic irradiation, increased sulfhydryl groups and amino acids reduced the dehydroalanine and, thus, decreased LAL content. Particle size, secondary structure, and microstructure (SEM, AFM) analyses showed relative dispersion in protein distribution, reducing intermolecular or intramolecular cross-linking, thereby lowering the LAL content. Thus, ultrasonic-aided pH-ST may be an operational technique toward minimizing LAL formation in RPI.