ARS | Publication request: MEMBRANE STRUCTURAL LIPID CHANGES IN FRESH-CUT CARROTS: REVISITING THE "WOUNDING AND AGING" PHENOMENON

Submitted to: Journal Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 1996
Publication Date: N/A

Interpretive Summary: Interpretive Summary Fresh-cut carrots are injured when they are submitted to the physical processes of peeling and slicing. If the tissues cannot recover from the injury, deterioration occurs rapidly. To develop methods or treatment for recovery, a better understanding is needed on the cellular changes that occur during and after processing. Thus a study was made to determine how the cellular membranes were affected by the processing actions. Results showed that membranes undergo breakdown with the physical actions of processing but new membranes were also being synthesized to repair torn tissues. The repair processes were strengthened when the tissues were treated with calcium. Thus calcium treatment would be beneficial in hastening the repair processes. This information is beneficial to other scientists working on ways to reduce deterioration of fresh-cut carrots an to the industry on a treatment for better quality fresh-cut carrots.

Technical Abstract: Technical Abstract Membrane lipid metabolism of fresh-cut carrots was studied because lipid catabolic processes result when membranes are ruptured. Membrane sterols and glycerolipids of shredded carrots were analyzed during storage at 10 degrees C. Total phospholipid and acylated sterol glycoside increased by as much as 31 to 135 percent, respectively, following 10 days of storage. These increases which were indicative of membrane restructuring processes, were accentuated by calcium treatment and appeared to be cultivar- dependent. During storage, calcium treatment also delayed the onset of increase in the ratio of free sterol:phospholipid and free stigmasterol: free sitosterol (senescence-driven processes) and reduced cell permeability. However, calcium treatment did not curb accumulation of phosphatidic acid, a membrane degradation product. The coexistence of of membrane degradation and "repair" processes appears to be characteristic of wounding and long-term storage of fresh-cut carrots. fresh-cut carrots.