Jump to Main Content
Effect of Pectin Methylesterase on Carrot (Daucus carota) Juice Cloud Stability
- Schultz, Alison K., Anthon, Gordon E., Dungan, Stephanie R., Barrett, Diane M.
- Journal of agricultural and food chemistry 2014 v.62 no.5 pp. 1111-1118
- Daucus carota, carrot juice, carrots, enzyme activity, microscopy, particle size, pasteurization, pectinesterase, residual effects, storage time, turbidity
- To determine the effect of residual enzyme activity on carrot juice cloud, 0 to 1 U/g pectin methylesterase (PME) was added to pasteurized carrot juice. Cloud stability and particle diameters were measured to quantify juice cloud stability and clarification for 56 days of storage. All levels of PME addition resulted in clarification; higher amounts had a modest effect in causing more rapid clarification, due to a faster increase in particle size. The cloud initially exhibited a trimodal distribution of particle sizes. For enzyme-containing samples, particles in the smallest-sized mode initially aggregated to merge with the second peak over 5â10 days. This larger population then continued to aggregate more slowly over longer times. This observation of a more rapid destabilization process initially, followed by slower subsequent changes in the cloud, was also manifested in measurements of sedimentation extent and in turbidity tests. Optical microscopy showed that aggregation created elongated, fractal particle structures over time.