Reuse of Bleaching Earth: The Green Solution for Rapeseed Oil Producers

Abstract

The main purpose of the presented research is to characterize the relationship between the amount of bleaching earth used in the bleaching process of rapeseed oil and the efficiency of this process. Changes in the content of chlorophyll and carotenoid pigments were examined using spectrophotometric and colorimetric methods. The process was carried out on a plate filter with different thicknesses of bleaching earth (BE) layers (1–3% in relation to the amount of oil). On the basis of the conducted research, a decrease in the content of chlorophylls (from 59 to 97%) and carotenoids (from 55 to 78%) was found, which affected the overall color of the oil. Based on the research results, it was found that the bleaching earth does not lose all of its adsorption properties after reaching the maximum, but they decrease in the next cycle. For some time, the sorbent can be used successfully, but to a lesser extent (40–45% of the original properties). This information is crucial as it will reduce BE consumption by up to 30% and shorten the oil bleaching cycle, as it will reduce the setup time of the machine.

The Influence of Storage Conditions of Cold-Pressed Rapeseed Oil on Its Quality Parameters

“…The increase in the a* parameter was solely associated with the breakdown of chlorophylls, which decompose under the influence of UV radiation. However, the simultaneous change in both parameters resulted from slower carotenoid degradation, as shown in previous studies [1]. Based on the above research, it can be concluded that cold-pressed vegetable oils are best stored away from sunlight.…”

“…Due to their health-promoting properties, vegetable oils are essential to a balanced human diet [1][2][3][4]. Apart from food applications, vegetable oils and their derivatives are also used in synthesizing polymeric materials, robotics, and 3D printing [5][6][7].…”

The Influence of the Used Bleaching Earth on the Content of Natural Dyes in Hemp (Cannabis sativa L.) Oils

“…The bleaching methodology was developed based on Marcinkowski et al [19] and Kwasnica et al [9] and patent method PL 232781. The bleaching process was performed in two stages.…”

“…The color of vegetable oils is determined by the carotenoid and chlorophyll pigments [18]. Excess chlorophyll pigments are responsible for faster oil oxidation, bitter taste, and dark green color [19]. Therefore, removing chlorophyll pigments by bleaching will positively affect the sensory properties and extend the shelf life of vegetable oils.…”