Changes In Color And Carotenoids Of Sweet Corn Juice During High-Temperature Heating

Background and objectives: Changes in color and carotenoid content of sweet corn juice due to thermal treatment were studied. The visual color was assessed using the CIELAB system, and predominant carotenoids were identified by the C-30-HPLC-APCI-MS technique.Findings: The color L* and b* values were overall decreased, while E value increased to some extent during heating treatment. First-order kinetic models were well applied to describe carotenoid changes with activation energies of 12.34-17.66 kJ/mol. Several carotenoids showed important changes and had different susceptibilities to high temperature. According to the principal component analysis, PC1 was associated with lutein, zeaxanthin, and -cryptoxanthin contents and PC2 with L*xb*/a* value. Limited degradation of carotenoids in juice system led to an imperceptible color change. However, the color L* value was a good indicator monitoring the changes in zeaxanthin and lutein of sweet corn juice.Conclusions: There was a good relationship between visual color L* value and dominant zeaxanthin/lutein content in sweet corn juice during thermal processing, suggesting the suitability of the visual color parameter in place of carotenoid content for online quality control.Significance and novelty: Although limited degradation of carotenoids in sweet corn juice system led to an imperceptible color change, the color L* value could be applied for monitoring the changes in zeaxanthin and lutein.