The impact of pulsed electric fields (PEF) and post-treatment time on the phenolic content and quality attributes of carrots was studied. Additionally, their influence on cellular permeability and viability was analyzed. Carrots were subjected to different electric field strengths (0.8, 2 and 3.5 kV·cm⁻¹) and number of pulses (5, 12 and 30). The largest increases in phenolic content were produced 24 h after applying 30 pulses of 0.8 kV·cm⁻¹ (40.1%) and 5 pulses of 3.5 kV·cm⁻¹ (39.5%). At such conditions, the colour was not affected but softening occurred after applying the highest electric field strength. Moreover, the increase in the specific energy input correlated with the decrease in cell viability. Carrot weight loss over time, media conductivity increase and cell viability decrease are related to the destabilization of cell membranes, which would entail a physiological response to stress, leading to a higher content in phenolic compounds.

Industrial relevance

Determining the response of plant tissues to processing technologies is of great interest from an industrial point of view. Pulsed electric fields (PEF), as well as other processing technologies, may trigger metabolic responses that are directly related to the quality of final products. This paper studies the impact of PEF treatments on the phenolic content and quality attributes of carrots. Results show that PEF application allows improving the polyphenol content in carrots. However, it must be considered that firmness, weight, and colour may suffer modifications if PEF parameters are not properly selected. The information provided could be beneficial to develop processed foods with enhanced health-related compounds content. Furthermore, in order to optimize treatments, it is critical to study structural changes as affected by PEF processing. In this study, tetrazolium staining and conductivity measurements were used to visualize and determine the cell damage on carrot tissues. Industry can apply PEF to achieve other aims such as enhancing intracellular metabolite extraction or improving the drying efficiency; therefore, PEF treatment suitability could be evaluated based on this approach. Results show that PEF could be a promising pre-treatment to enhance the phenolic content of carrots and obtain derived products with improved nutritional value.

中文翻译：

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在处理后的时间内通过脉冲电场提高胡萝卜中的酚含量：对细胞活力和质量属性的影响

研究了脉冲电场（PEF）和后处理时间对胡萝卜中酚含量和品质属性的影响。另外，分析了它们对细胞通透性和生存力的影响。胡萝卜要经受不同的电场强度（0.8、2和3.5 kV·cm ^-1）和脉冲数（5、12和30）。施加30脉冲0.8 kV·cm ^-1（40.1％）和5脉冲3.5 kV·cm ^-1后24小时产生最大的酚含量（39.5％）。在这样的条件下，颜色不受影响，但是在施加最高的电场强度后发生了软化。此外，比能输入的增加与细胞活力的降低相关。胡萝卜重量随时间的流失，培养基电导率的增加和细胞活力的降低与细胞膜的失稳有关，这会引起对压力的生理反应，从而导致酚类化合物含量更高。

行业相关性

从工业的角度来看，确定植物组织对加工技术的响应非常重要。脉冲电场（PEF）以及其他加工技术可能会触发与最终产品质量直接相关的代谢反应。本文研究了PEF处理对胡萝卜中酚含量和品质属性的影响。结果表明，PEF的使用可以改善胡萝卜中的多酚含量。但是，必须考虑的是，如果未正确选择PEF参数，则硬度，重量和颜色可能会受到影响。提供的信息可能有益于开发具有增强的健康相关化合物含量的加工食品。此外，为了优化处理，研究受PEF加工影响的结构变化至关重要。在这项研究中，使用四唑鎓染色和电导率测量来可视化并确定胡萝卜组织上的细胞损伤。工业界可以将PEF应用于其他目的，例如增强细胞内代谢产物的提取或提高干燥效率；因此，可以基于这种方法评估PEF的治疗适应性。结果表明，PEF可能是一种有前途的预处理方法，可以提高胡萝卜中的酚含量，并获得具有更高营养价值的衍生产品。PEF治疗的适应性可以根据这种方法进行评估。结果表明，PEF可能是一种有前途的预处理方法，可以提高胡萝卜中的酚含量，并获得具有更高营养价值的衍生产品。PEF治疗的适应性可以根据这种方法进行评估。结果表明，PEF可能是一种有前途的预处理方法，可以提高胡萝卜中的酚含量，并获得具有更高营养价值的衍生产品。