Introduction
Animal fats have long been used around the world as a source of hard fats in cooking and industrial food production. Think high-saturated fat products like butter or lard. Concerns about the cost and health implications of consuming large quantities of animal fats, however, led to the increasing use of artificial trans fats instead. These artificial trans fats are produced from vegetable oils, which are partially hydrogenated to transform them into a solid or semi-solid state.
Today, we know that artificially produced industrial trans fats do not support human health either – evidence has shown connections between the consumption of trans fats and cardiovascular health issues. The solution? Interesterified fats.
Used as a hard fat in confectionary products, bakery products, spreads, etc., interesterified fats provide necessary functional properties – shelf stability, improved texture, and lower melting point. They make it possible for food product manufacturers to create shelf-stable cookies, biscuits, spreads, and other such products.
The interesterification process lies at the centre of it all.
Whether you want to set up an interesterification plant or understand the full value chain of plant-based oils, you must understand the interesterification process. In this blog article, we’re going to explore the interesterification process and how it’s different from hydrogenation and fractionation. We’ll also explore its role in public health and circular economy. Let’s dive right in.
Oils and fats modification.
Whether you rely on interesterification, hydrogenation or fractionation, why must you modify oils and fats in the first place?
Well, oil and fat modification improves the stability of highly unsaturated oils. It protects the oil from going bad by preventing oxidation, thereby extending its shelf life. Considering that the same oils and fats may be used for diverse purposes, fat modification can also create specific fractions with specific functionalities.
For instance, fractionation, a physical process, can be used to separate oil or fat into liquid and solid fractions, yielding stearin and olein fractions. These different fractions are meant for diverse food and specialty applications.
Then come the processes of interesterification and hydrogenation. While these processes are similar in that they are both chemical processes, the specific reaction is different in interesterification vs hydrogenation.
Interesterification redistributes fatty acids within and across triglycerides. Effectively, this blends the functional properties of different oils. Interesterification can be carried out via chemical or enzymatic processes, the latter requiring milder process conditions and being more sustainable.
On the other hand, hydrogenation adds hydrogen atoms to unsaturated bonds in triglycerides. It improves the fat’s texture and stability. This process usually requires a catalyst and can be carried out in batch, semi-continuous, and continuous processing, enabling selective or full hydrogenation, as needed.
Today, there are also greener and safer oil and fat modification techniques like enzymatic interesterification and specialty fats fractionation. These modern techniques are quite efficient, requiring milder process conditions, not producing any chemical residues, and improving the sustainability of fat modification processes.
The interesterification process.
Dietary fats generally consist of triacylglycerols (TAG), which are essentially three fatty acids esterified to a glycerol backbone. The fatty acids may be positioned in any one of three places on the glycerol molecule; depending on their position, they may be labelled sn-1, sn-2, or sn-3.
Now, the position of the fatty acid on the glycerol molecule determines the physical and biochemical properties of the fat or triacylglycerol. These properties could be the level of unsaturation of the fat, the length of the fatty acid chain, etc. which affect the texture and stability of the fat. To change these properties, we rely on interesterification.
The interesterification process swaps or rearranges fatty acids within the triacylglycerol or between different triacylglycerols. The interesterification process can be chemical or enzymatic. It can also be random (in which fatty acids are moved to unspecified positions) or directed (in which fatty acids are moved to specific positions).
The interesterification process can be used to create diverse molecular compounds. The process may be deployed to create fats with a specific positional composition, say infant formula with a positional composition identical to that of breastmilk. Or to create fats with certain physical properties, say, a specific melting point or solid fat content.
If you’re setting up an interesterification plant, your plant operations would involve controlled reaction, bleaching, and filtration stages. Your oil or fat feedstock would be treated with a sodium methoxide catalyst in a reactor; here, the fatty acids would get redistributed across the triglycerides. The mixture would have to be circulated through an autoclave to make sure the reactants mix well and react completely. Magnetically-driven agitators would support with full vacuum sealing and low-maintenance operations. Finally, you would need double spiral coils for effective temperature control.
You wouldn’t immediately get usable interesterified fats after the interesterification process. Bleaching would be required to eliminate pigments and other impurities. After bleaching and then filtration, the final product would be transferred to storage.
Setting up an interesterification plant? Your role in public health and the circular economy.
If you’re setting up an interesterification plant, you should know your market. For years now, governments around the world have recommended that the public reduce the saturated fatty acid content in their diet.
First, the food industry relied on structural geometry changes in partially hydrogenated vegetable oil to create trans fatty acids. Shelf-stable, with a relatively high melting point, high solid fat content, and similar physical properties as high melting point saturated fats.
But as we saw right at the beginning of this post, artificial trans fatty acids have also been now shown to be associated with coronary heart disease.
Interesterification (along with blending, fractionation, full hydrogenation, etc.) is the answer.
Interesterified fats are, thus, an important part of the answer to the cardiovascular health crisis.
The interesterification process is also critical from a circular economy perspective. This is because this and other fat modification processes extend the life of oils and fats by transforming them into higher value products. With every step in this extended value chain, your interesterification plant reduces waste and creates new applications for oils and fats.
Kumar is the EPCC partner your interesterification plant needs.
Setting up an interesterification plant is a complex endeavour, with many tiny details and moving parts. You need a reliable EPCC partner to help you throughout the process, from plant design and engineering to installation, maintenance, audits, and beyond. That’s where we come in.
At Kumar, our comprehensive suite of fat modification equipment is our pride. As we tread a path of sustainability in food, feed, fuel and circular economy applications, our fractionation systems, hydrogenation reactors, enzymatic processing modules, and of course, our interesterification units help our clients create more value.
Our fat modification equipment is engineered for flexibility; it can be seamlessly integrated into turnkey plants. Our suite of solutions promises product uniformity, delivering consistent performance over time. With our fat modification line and beyond, we promise high-quality output, energy efficiency, and long-term reliability: all the elements you want in a sustainable, high-performance operation.
If you’re ready to dive in, get in touch with us today. Our expert team has just what it takes to deliver the interesterification plant you need.
