Effect of Ultrasound Immersion Freezing on the Quality Attributes and Water Distributions of Wrapped Red Radish

• DOI: 10.1007/s11947-015-1496-x
• Publication Date: 2015-03-14T07:47:04Z
• Authors: Bao-guo Xu; Min Zhang; Bhesh Bhandari; Xin-feng Cheng; Jincai Sun
• Keywords: Free water; Immersion

The microstructures, quality attributes (drip loss, firmness, sensory evaluation, and calcium content), and water distributions of ultrasound immersion frozen red radish (wrapped or unwrapped) were investigated. The results showed that ultrasonic treatment can significantly (p < 0.05) decrease the freezing time and better preserve the quality of frozen radish samples. In addition, ultrasound immersion frozen radish samples had smaller pore size and less destructive effect on microstructures from the scan electron microscopy (SEM) analysis. Wrapped radish had significantly (p < 0.05) lower calcium content, indicating that wrapped treatment was able to effectively prevent the solute uptake from the coolant to the radish samples. The water distributions of unwrapped samples were more uniform from the pseudocolor images of magnetic resonance imaging (MRI). Low-field nuclear magnetic resonance (LF-NMR) relaxation measurements showed that the vacuole water decreased, while the relative cytoplasm and intercellular space water increased under ultrasonic and unwrapped treatment.