Changes in Caffeic Acid Derivatives in Sweet Potato (Ipomoea batatas L.) during Cooking and Processing
There was an obvious decrease in caffeic acid derivatives during the boiling of cube-shaped blocks of sweet potatoes. They also decreased in a mixture of freeze-dried sweet-potato powder and water maintained at room temperature. Ascorbic acid prevented the decrease, supporting the occurrence of an enzyme reaction with polyphenol oxidase (PPO). 5-<I>O</I>-Caffeoylquinic acid (5-CQA, "3-<I>O</I>-caffeoylquinic acid" as a trivial name) and 3,5-di-<I>O</I>-caffeoylquinic acid (3,5-CQA), major phenolic compounds of sweet potato, did not change when they were separately heated in boiling water. When the mixture of powdered sweet potato and water was heated at 100 °C, there was only a negligible decrease in the total amount of phenolic compounds, and portions of 5-CQA and 3,5-CQA were found to be isomerized to 3-CQA, 4-CQA, 3,4-CQA, and 4,5-CQA. The content and composition of the phenolic compounds in sweet potatoes differed between fresh and long-stored ones, as did their response to heating.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(1), 172-177, 2006-01-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry