Saved Bookmarks
| 1. |
A number of attempts have been made to preserve the green colour of heat-processed greenvegetables. Chlorophyllides are more stable than chlorophylls. Therefore, chlorophylls are convertedto chlorophyllides by means of the naturally occurring chlorophyllase. However, this enzymefunctions at a temperature in the range of 65-75°C. Because of the high temperature used, productsprocessed by this method lose colour on standing. Another method is the use of alkalizing agents toproduce a higher pH in the system and thus minimize pheophytin formation. High-temperature-short-time (HTST) processing has also been used to stabilize the molecule during heat processing. However,there is always some deterioration of chlorophylls with storage, whatever the processing method used. |
|
Answer» Answer: Chlorophyll degradation during thermal processing of green vegetables leads to losses in COLOR and consumer appeal. Rapid formation of olive-colored pheophytin and pyropheophytin during heating is initiated by the release of cellular acids and CONTINUES during storage. Previous efforts to maintain the color of heat processed vegetables have met with limited success. Green metallocomplexes of chlorophyll DERIVATIVES formed during thermal processing have been observed and offer a possible solution to the problem of color loss. In this review, the chemistry of chlorophyll and its derivatives formed during thermal processing are presented. Also discussed is the technology of color preservation of green vegetables including RECENT developments on regreening of commercially CANNED green vegetables through the formation of metallocomplexes. Mark As Brainliest Please. |
|