Development of a method for chlorophyll removal from canola oil using mineral acids

Because of the high level of chlorophyll‐type compounds found in canola oil, bleaching is an important and critical step in the canola oil refining process. In this study, a new method for reducing the chlorophyll‐type impurities prior to the bleaching step was developed. This method is based on precipitating the chlorophyll compounds with mineral acids. Concentrations of chlorophyll‐type compounds of up to 30 ppm could be reduced to amounts of less than 0.01 ppm by mixing the crude canola oil with a 0.4 wt% mixture of phosphoric and sulfuric acids (2:0.75, vol/vol) for 5 min at 50°C. Centrifugation and filtration also were examined as two main methods for separating the chlorophyll precipitates. The results showed that filtration by a precoated textural filter with filter‐aid clay could separate the precipitates as well as the centrifugation method.