His contributions and achievements to our industry are indicated by the awards he has received including these awards from AOCS: Alton E. Bailey Award, PRO Division Distinguished Service Award, Stephen S. Chang Award and the Timothy L Mounts Award. In addition, he was named an AOCS Fellow in 2010 and Emeritus member in 2020. He continues to support AOCS as a frequent contributor to inform|connect. He wrote the processing chapters in The Lipid Handbook, 3rd Edition (2007), and his book, Edible Oil Processing from a Patent Perspective, is available through Amazon. The bulk of this book dissects our processes and applicable patents and provides a unique perspective into the industry particularly post-1990.
Dr. Dijkstra, now retired, recently took the time to answer questions from the Processing Division Newsletter Editor, Brent German:
What do you wish you had known when you first started?
Like most people, I have always learned on the job. I had not a clue about oils and fats when I joined Vandemoortele. I did not have much of a clue about process technology when I became chief chemist for two ICI polymer plants in 1968 either. I was outside of R&D while at ICI and missed the development of NMR and MS as working tools rather than specialists' affairs. Because of that, I continued to consider them as expensive and exclusive.
What has been the most challenging technical issue that you personally ran into regarding oilseeds?
Designing an improved mechanism for the partial hydrogenation reaction has been my biggest challenge, followed closely by chemically catalyzed interesterification. In both instances, suggestions were made a long time ago and people took those assumptions for granted although subsequent observations disagreed. It was necessary to study the literature and observations critically and with an open mind to identify patterns and solutions. For hydrogenation, this was the notion that the hydrogen concentration in the oil is not constant but starts at a low level and gradually increases. For interesterification, this was the introduction of the enolate anion that enabled all observations to be explained. How did I solve them? Many sleepless nights!
What is the biggest technical challenge in oilseeds today?
Modern plants are big to profit from economy of scale. Nobody wants to risk that a novel process for fear it will not live up to its expectations. Many companies seem to say "as long as the others don't innovate, I don't need to either". Overcoming this barrier against process innovation could be the biggest challenge. For example, in my paper Neutral oil loss during alkali refining (JAOCS, 89:175-177, 2012), I suggest washing crude oil with a solution of caustic soda in a mixture of water and isopropanol. The isopropanol will not cause any transesterification, when mixed with water as oil does not dissolve in aqueous isopropanol but soap and phosphatides do. This should make a better separation with lower loss. The equipment exists but the process continues without evaluation despite the potential.
What are you enjoying now?
Apart from spending time with my wife – the lockdown in Belgium certainly helped with that – I certainly enjoy my freedom since retirement. I do not have to justify how or on what problem I spend my time and I have hardly any deadline to meet. I also enjoy embroidery. When on holiday in Portugal, my wife and I saw a kind of tapestry we could not place. It turned out to be the plaited stitch as practiced for centuries in Arraiolos. Now I gather and sort out my thoughts by embroidering Arraiolos carpets and after having sorted them out, I go back to my computer. I have invented novel ways of carrying out the stitches and am working on a book about it.
I am quite pleased that the use of plasma emission spectrometry to determine phosphorus and other trace elements, which I pioneered and published in JAOCS in 1982 has now become an AOCS Official Method. I am also glad that inform|connect is doing well. I regard this as my baby, and it is nice to see this platform grow up and do well.