Searching for resins compatible with food oils
In a student master thesis, we conducted a study using conventional adsorbents and regular ion exchange resins, equivalent to those from large resin suppliers. Our aim was to find adsorbents or resins that can be employed in food oils such as citrus oil, linseed oil and other oils – to remove undesired components such as citrus wax or undesired contaminations such as rancidity compounds.
One aim we had was to remove the wax in citrus essential oil using adsorbents and ion-exchange resins. When essential oils are used as flavoring, excess levels of waxes in the essential could lead to cloudiness in the final food product. Conventional methods to remove citrus wax are typically by winterization where the essential oil is left at sub-zero tempereratures for several weeks. At cold temperatures, the wax precipitates out of solution and can be separated from the essential oil. A disadvantage of this method is that citrus grows in warm countries and cooling large amounts is costly. Therefore, the idea of using an adsorbent or ion exchange resin that binds the wax at ambient temperature was appealing – and it still is.
After evaluating a broad collection of conventional resins and adsorbents, the outcome was bleak. Not one resin showed any clear signs of capacity to bind waxes.
Likewise, a similar collection of conventional ion exchange resins and adsorbents was screened for their ability to bind rancidity compounds from stored linseed oil. Linseed oil with its high level of unsaturated fats is a particularly sensitive oil prone to oxidation and gets easily rancid. So the aim was to find resins that would bind undesired rancidity compounds such as oxidated compounds.
An analysis of the physical structure of those conventional resins brought us to the following conclusion: conventional resins that are widespread today and that are water-optimized ion-exchangers or similar materials are not well compatible with non-aqueous solutions such as oils. A logical next step would be that new resins with other physical properties are required for employment in oils and organic solvents. Redstone Separations therefore worked on a new class of polymeric resins and ion exchange resins: the RR series (Rigid Resins). RR resins have a higher rigidity than most of the conventional resins on the market giving it a permanent porosity even in non-aqueous solutions like oils or organic solvents. The link to those resins is here and more applications and uses will be published when completed. Inquiries are welcome where a collaboration on designing and optimizing resins for oils can be conducted together or as a custom project. Pls contact us for a discussion: info@redstone-sep.com
