Chlorophyll Reduction in Harvested Canola
Date: August 26, 1994
Term: 1 year
Status: Completed
Researcher: Gordon Hultgreen, Prairie Agricultural Machinery Institute
SaskCanola Investment: n/a
Total Project Cost: n/a
Funding Partners: n/a
Project Summary
In 1991, canola was the second largest crop in Saskatchewan, with annual production of about 1.7 million tonnes. With over half of Canada’s canola and canola oil exported, some customers had expressed concern over the high levels of chlorophyll in the seed or crude oil. The objectives of this study were to determine the effects of various temperatures, light levels and moisture contents on the breakdown of retained chlorophyll on stored canola. From the study, researchers concluded that none of the storage conditions could definitely be shown to reduce the retained chlorophyll levels in canola.
In 1991, canola was the second largest crop in Saskatchewan, with annual production of about 1.7 million tonnes. With over half of Canada’s canola and canola oil exported, some customers had expressed concern over the high levels of chlorophyll in the seed or crude oil. Chlorophyll is difficult and expensive to remove during oil processing and potential losses to producers from downgrading was significant. Researchers hoped to find a post-harvest control or chlorophyll reduction technique that would help farmers achieve optimum grades while still harvesting within the constraints of Saskatchewan’s weather. Research results to date had been inconsistent.
This study was done to determine the effects of various temperatures, light levels and moisture contents on the breakdown of retained chlorophyll on stored canola. Samples of canola with high levels of retained chlorophyll were stored under different levels of these variables for a six-month period. Two different moisture contents (9.3 and 6.1%), three temperatures (-5, +5 and +15C) and two light conditions (complete darkness and under grow light) were used. Crush plate tests were done at the beginning, periodically throughout and at the end of the storage period to determine the degree of effectiveness of the storage condition in reducing the chlorophyll content.
From this study, it can be concluded that none of the storage conditions could definitely be shown to reduce the retained chlorophyll levels in the canola. The results showed there may have been a slight trend towards fewer green seeds in the higher moisture canola stored at 15C. Researchers recommended more research be carried out with a minimum storage temperature of 15C, with less emphasis on different levels of light and moisture.