Pellicer José Antonio, Gómez-López Vicente M
Departamento de Ciencia y Tecnología de Alimentos, Universidad Católica de Murcia (UCAM), Campus de los Jerónimos 135, Guadalupe 30107, Murcia, Spain.
Cátedra Alimentos para la Salud, Universidad Católica de Murcia (UCAM), Campus de los Jerónimos 135, Guadalupe 30107, Murcia, Spain.
Food Chem. 2017 Dec 15;237:632-637. doi: 10.1016/j.foodchem.2017.05.151. Epub 2017 May 31.
Pulsed light (PL) is a non-thermal preservation method in which foods are subjected to one or several intense pulses of wide-spectrum light. Peroxidase (POD) is an enzyme that needs to be inactivated or inhibited because of its deleterious effects on the quality of fruits and vegetables. The feasibility of using PL to inactivate POD was tested and results explained based on measurements of UV-vis spectrum, far-UV circular dichroism and tryptophan fluorescence, and the phase-diagram method. PL reduced the activity of POD by more than 95% after applying 128Jcm. There was observed a decrease in the Reinheitzahl value and ellipticity and an increase in tryptophan fluorescence at incremental fluences, as well as linear phase diagrams. The study indicates that the inactivation of POD by PL is an all-or-none process related to loss of helical structure, weak unfolding and ejection of the prostetic group.
脉冲光（PL）是一种非热保鲜方法，即让食品接受一次或几次宽光谱光的强烈脉冲照射。过氧化物酶（POD）是一种因其对水果和蔬菜品质有不良影响而需要使其失活或受到抑制的酶。基于紫外可见光谱、远紫外圆二色性和色氨酸荧光测量以及相图法，测试了使用脉冲光使过氧化物酶失活的可行性并对结果进行了解释。施加128J/cm²的脉冲光后，过氧化物酶的活性降低了95%以上。随着光通量增加，观察到赖因黑茨值和椭圆率降低，色氨酸荧光增加，以及线性相图。该研究表明，脉冲光使过氧化物酶失活是一个与螺旋结构丧失、弱解折叠和辅基弹出相关的全或无过程。
