Submitted to: Food Preservation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 1997
Publication Date: N/A
Interpretive Summary: Yellowing of fresh-cut spinach is not appealing to consumers and has a negative effect on sale of the product. Yellowing occurs when the pigment chlorophyll is degraded, and is affected by many factors including antioxidants that are present in plant cells. Two antioxidants present in substantial quantity are ascorbic acid and beta- carotene. A study was made to determine the extent to which these two antioxidants protect the chlorphyll. The study indicated that the antioxidants inhibited the reaction which degrades chlorophyll, and that ascorbic acid was more effective at protecting chlorophyll than beta- carotene. This information can be used in developing new genetic lines of spinach with high levels of ascorbic acid to protect chlorophyll. This will benefit consumers in obtaining a high quality fresh-cut product which does not yellow reapidly.
The effects of antioxidants L-ascorbic acid (AsA) and beta-carotene on chlorophyll (Chl) degradation by a peroxidase-hydrogen peroxide system were determined, and the relationship of the Chl degradation to the antioxidant contents in stored spinach (Spinacia oleracea L.) leaves treated with ethylene was studied. The antioxidants reduced Chl degradation by inhibiting the peroxidase-hydrogen peroxide reaction system. AsA and beta-carotene contents in spinach leaves decreased during storage at 25 degrees C. Chl content decreased sharply when AsA was added and gradually with the addition of beta-carotene. Degradation of Chl and AsA was hastened when the spinach leaves were treated with 10 ppm ethylene, and the degradation of AsA preceded that of Chl. Thus, AsA was more effective than beta-carotene in protecting the Chl, but the effect was lost when AsA content dropped below a threshold level.