Abstract

Ultrasound-pretreated centrifugal dewatering (UCD) is a novel method for vegetable dewatering process in the central kitchen. In this study, carrot cubes were blanched and dewatered by UCD at various ultrasonic frequencies (0, 20, 30, 45, 80 and 100 kHz). Conventional centrifugal dewatering (CCD) was performed for comparison. At similar centrifugal conditions, the dewatering capacity of UCD was >30% higher than CCD. The retention of β-carotene, phenolic and flavonoid substances also increased by 10–50%. The optimized ultrasonic frequency for UCD processing was 45 kHz. At this optimized condition, the reducing power of carrot cubes was improved by 3.4%. Retention of total phenolics, flavonoids and β-carotene were increased by 33.89%, 48.51% and 26.71%, respectively. Nevertheless, a moderate reduction (25.82%) of hydroxyl radical scavenging capacity was observed for the UCD. Overall, UCD can be used as an alternative improved method of CCD to enhance the dewaterability and quality of carrot.

• Highlights

• Ultrasound-pretreated centrifugal dewatering (UCD) improved dewaterability of carrot and retained its nutritional values.

• UCD increased the dehydration rate of carrot by >30% than conventional centrifugal dewatering (CCD).

• The β-carotene, phenolics and flavonoids substances in UCD carrot was 10-50% higher than that of CCD.

• UCD has a positive effect on antioxidant activity of carrot.

摘要

超声波预处理离心脱水（UCD）是一种新型的中央厨房蔬菜脱水工艺方法。在这项研究中，胡萝卜块在不同的超声波频率（0、20、30、45、80 和 100 kHz）下通过 UCD 进行热烫和脱水。进行常规离心脱水 (CCD) 以进行比较。在类似的离心条件下，UCD 的脱水能力比 CCD 高 30% 以上。β 的保留-胡萝卜素、酚类和黄酮类物质也增加了 10-50%。UCD 处理的优化超声波频率为 45 kHz。在此优化条件下，胡萝卜块的还原能力提高了 3.4%。总酚类、黄酮类和β-胡萝卜素的保留量分别增加了33.89%、48.51%和26.71%。然而，观察到 UCD 的羟基自由基清除能力适度降低 (25.82%)。总体而言，UCD 可用作 CCD 的替代改进方法，以提高胡萝卜的脱水性和质量。

• 强调

• 超声预处理离心脱水 (UCD) 提高了胡萝卜的脱水能力并保留了其营养价值。

• UCD 将胡萝卜的脱水率比传统离心脱水 (CCD) 提高了 30% 以上。

• UCD胡萝卜中的β-胡萝卜素、酚类和黄酮类物质比CCD高10-50%。

• UCD对胡萝卜的抗氧化活性有积极作用。