The Difference Between Partial and Full Invert Sugar

Invert sugars are some of the most widely used ingredients in industrial food and beverage production because they serve vital functional purposes, as well as acting as sweetness enhancers. This blog explains the differences between the two main types: partial and full invert sugar syrups, and details how the properties of each benefit their respective applications.  

Invert sugar is sugar that has been inverted. But what does this mean? Invert sugar syrup is typically sucrose – white table sugar – that has been transformed into a sweeter sugar product with different functional properties. Once this process has taken place, light shines through invert sugar in the opposite direction than it does through straight sucrose and, therefore, it is ‘inverted’.

Sugar manufacturers produce invert sugar by breaking down the ‘disaccharide’ (literally ‘two sugar’) bond between the glucose and the fructose molecules in straight sucrose. The glucose and fructose molecules are then free ‘monosaccharide’ molecules (single sugars).  

This inversion process is subtly altered to produce partial and full invert sugar syrup. You can find out more about the differences between the two production processes on our inverted sugar syrup product page. 

The monosaccharides produced by the inversion process, fructose and glucose, are identical chemically, but have different molecular structures. Fructose is much sweeter than sucrose, and sweeter than glucose, because of this structure. Therefore, invert sugar syrups are sweeter than sucrose-based liquid sugars. 

Invert sugars also occur naturally. Both honey and the sap of a daffodil are naturally occurring invert sugars, for example. However, in sugar products made from natural sugars, partial and full invert sugar syrups are typically produced at scale because the processes involved require extensive sugar expertise and world-class manufacturing equipment to deliver consistent and quality results. 

Let’s break down the differences between partial and full invert sugar syrup. 

Partial invert, also labelled by some as medium invert, retains more sucrose from its production process, simply because it is only partially inverted. A partial invert is typically a combination of 32.5-35.5% sucrose to 42.5-45.5% invert, but it is important to remember that this ratio varies depending on the partial invert being produced. 

With more sucrose retained in the syrup, partial invert tends to have a yellow tint. As nearly half of the sucrose has been inverted into sweeter tasting fructose and glucose, partial invert is approximately 20% sweeter than straight sucrose. However, this represents a key distinction between partial and fully inverted sugar syrup: partial invert is much sweeter than straight sucrose but typically only half as sweet as a full invert. 

Partial invert also has a much lower water content than straight sucrose. As a result, this increases its preservative qualities, reducing crystallisation and enabling it to withstand higher temperatures during manufacture. 

A full invert retains less sucrose from its production process because it has been fully inverted. This means most of the sucrose has been converted into fructose and glucose molecules. A typical analysis shows that full invert is a mixture of 3.5-5.5% sucrose to 71-77% invert, however, the ratio varies depending on the full invert being produced. 

Partial invert has a clearer appearance than full inverts. Because full inverts are inverted for longer, the sugars ‘burn’ for longer and therefore have a yellower tint or slightly darker appearance. For this same reason, with so much more fructose, full invert has a sweetness value approximately 40% higher than straight sucrose and 20% higher than partial invert. 

Both partial and full invert sugar applications are integral to the development of a high-quality end product, but they are often used in different ways. 

Both types of invert syrup are used as humectants because they retain the moisture and prevent microbial spoilage, however, there is an important difference between the two inverts. Partial inverts have a longer shelf life than full inverts and are more often primarily used for this quality.  

In terms of specific applications, partial invert sugar syrup is a highly popular ingredient for soft drinks manufacturers because its high sweetness value results in a better flavour than artificial sweeteners while also enabling a 20% reduction in sucrose used. Furthermore, partial invert also lends itself to the production of cereal bars, mixes, cakes and flapjacks, enhancing the flavour and extending the shelf life of all. 

On the other side of the spectrum, full invert is often used in icings and fondants due to its higher sweetness value. In such applications, it also prevents crystallisation and keeps the products soft and smooth. Similarly, it is used as a replacement for glycerine in low-fat baking products and to prevent crystallisation in confectionery production. 

Full invert is also notably used as a sweetener and bulking agent in ice creams, frozen desserts and sorbets. In ice cream applications, for example, full invert plays a crucial functional role by depressing the freezing point of the product and ensuring a soft and scoopable texture. 

Partial invert and full invert sugar syrup have different properties and uses. The distinction between the two is complex because the formulations of both types of invert must meet the requirements of the specific end product. Those features are what makes invert sugar syrups such versatile and popular sugar products. 

But to make matters more complicated, some of these variations of partial invert sugar syrup are widely recognised sugar products in their own right. Golden syrup and refiners syrup, for instance, are both examples of partially inverted sugar syrups that are better known for being independent sugar products than for being partial inverts. 

Not only that, though, there is also confusion over whether invert sugar syrup and high-fructose syrup – also known as inverted corn syrup – are the same product, particularly in North America. They are not. 

While both contain glucose and fructose and have similar taste, they are distinguished from each other by their raw materials and production processes. Invert sugar is made from natural sugar derived from sugarcane or sugar beet via an inversion process, whereas high-fructose syrup is a product manufactured from either corn or wheat. 

High-fructose corn syrup is derived from corn or wheat starch via two steps. First, enzymatic hydrolysis of starch to glucose is followed by isomerisation of glucose into fructose. Then, there’s a fractionation process to make the final product.

These differences result in distinct properties and qualities. 

Organic invert sugar syrup is produced from organic sugar beet or sugarcane. Organic farming is generally acknowledged to mean farming crops and production animals without the use of artificial chemicals, fertilisers and pesticides. Organic food production is typically governed by legal standards, so all organic farmers are subject to strict regulations.  

Organic farming standards can vary significantly according to the local legislation and there is no global standard. Organic invert sugar syrups are the same product as non-organic sugar syrups. The only difference is that the sugarcane and sugar beet used was grown according to a local organic farming framework. 

The differences between partial and full inverts are complex and nuanced. In short, although the two products are made through similar processes, their differences in sweetness, texture giving properties, and ability to extend shelf-life make them vital ingredients in different kinds of food products. 

Ragus supplies high-quality full and partial invert sugar syrups to industrial food and beverage producers to enhance product tastes, textures, appearance, and shelf life. To learn more about our pure sugars, contact a member of our Customer Services Team. For more sugar news and Ragus updates, keep browsing SUGARTALK and follow Ragus on LinkedIn.