Beyond the Sugar and Cream
How Do Emulsifiers and Stabilisers Shape Ice Cream?
Milk, sugar, cream, and eggs. The vast majority of ice cream, whether homemade or store-bought, starts with these few ingredients. So what makes the two so different?
First, let’s start with the overall process of making ice cream at home:
Sound simple enough?
Industrially, ice cream is still produced based on the same set of fundamental steps, but with some additional processing that utilizes specialized factory equipment needed to produce large batches at a time and ensure the consummability and longevity of the products.
Below is a rough outline of the industrial method of making ice cream:
With significantly more steps in creating manufactured ice cream, deviations in their taste, appearance, and texture are sure to exist. In particular, we will focus on the variations in texture between the two. So what causes this difference? Unlike homemade ice cream’s simple and short ingredient list, manufactured ice cream contains more additives to ensure that it can withstand its rigorous processing steps and endure a long shelf life in your freezer at home. Two such additives go by the names of emulsifiers and stabilisers.?
How do emulsifiers affect ice cream?
Ice cream is considered a type of emulsion, which is a combination of fat and water that typically separate when mixed together. In an emulsion, however, these fat molecules are distributed throughout the water instead of separating. Emulsifiers, such as lecithin and mono- and diglycerides, are crucial in ice cream for creating this stable emulsion of fat and water. By reducing the surface tension between these immiscible components, emulsifiers allow fat droplets to disperse evenly throughout the mix and prevent them from coalescing. This stabilisation is essential for incorporating air, which contributes to an improved mouthfeel in the final product.
What role do stabilisers play in ice cream?
Stabilisers enhance the texture of ice cream by giving it a smoother consistency and increasing viscosity. This water-soluble substance typically comes from plants or bacteria, and common varieties include carrageenan, sodium alginate, and guar gum. Stabilisers absorb water and form a gel-like network that increases the viscosity of the mix, trapping water and air to prevent the formation of large ice crystals. Stabilisers also have an additional role similar to that of emulsifiers in helping maintain the integrity of the ice cream by preventing the separation of water and fat.
How do these affect the ice cream production steps listed earlier?
In the initial pre-heating and mixing step, emulsifiers and stabilisers are evenly added into the ingredient mixture. Later in the homegenisation step, emulsifiers activate their function and reduce the surface tension between the fat and water phases, allowing them to separate and create a stable emulsion. This breaks down fat droplets into smaller ones, dispersing them throughout the mixture. Stabilisers also play a role, stabilising this newly formed emulsion and keeping the fat globules from coalescing. Later, stabilisers also start to build viscosity during the cooling process, maintaining the structure.
During aging, stabilisers hydrate fully, absorbing water to form a gel-like network that increases the viscosity of the mixture. Emulsifiers also continue to interact with fat droplets, improving the texture and body of the ice cream. This step is followed by continuous freezing, where emulsifiers assist in incorporating air and stabilising the fat structure, delivering smoothness. Both emulsifiers and stabilisers aid in preventing the formation of large ice crystals, promoting a creamy consistency.
Lastly, stabilisers continue to maintain the ice cream’s texture as their gel networks trap water and air throughout the remaining packaging, hardening, storage, and distribution steps. This prevents melting, separation, and ice crystal formation.
Tying it all together: how do emulsifiers and stabilisers change the texture of factory ice cream compared to its homemade counterpart?
Homemade Ice Cream is Softer and More Airy
Ice cream made from scratch feels softer, fluffier, and more airy. Without emulsifiers, homemade ice cream tends to have larger air bubbles and a less uniform fat distribution, leading to a softer texture. Store-bought ice cream, on the other hand, has a consistent composition of fat, milk protein, emulsifier, and stabiliser. This keeps the volume of air strictly controlled throughout its aeration and freezing process, giving it a lower air content and therefore a higher density. Because the fat is evenly distributed and the air bubbles are smaller and more uniform, the ice cream ends up with a firmer texture. Each bite of ice cream is also less watery, largely thanks to the stabiliser’s ability to hold water in place and enrich creaminess.
Homemade Ice Cream Melts Faster
In addition to the overall mouthfeel, both forms also exhibit a difference in melting rates. Generally, supermarket ice cream melts more slowly than homemade ice cream.?
Because stabilisers and emulsifiers help to stabilise the pockets of air in the ice cream, the air is able to protect the ice cream from the effects of heat. Moreover, these two additives allow fat globules to disperse evenly throughout the ice cream, forming a stable network that holds water and fat in place, enhancing the structural integrity of ice cream even as it warms up. Thus the ice cream will melt more slowly as a result.
This way, store-bought ice cream will be able to survive the long drive home without fully melting before it gets stored in the freezer.
What are some examples of exceptional factory-scale stabilisers and emulsifiers?
Curdlan
One example of an exceptional stabiliser is curdlan, a gel produced via microbial fermentation of glucose that forms a stable gel when heated. It is colorless, odorless, non-toxic, and absorbs water exceptionally well. Thus, it can bind to water and prevent separation in food, strengthening structure and stability. Its versatile properties make it the ideal additive in the dairy industry, and it is particularly useful for maintaining shape in ice cream.
Ryoto Sugar Ester Emulsifiers
Despite the wide variety of commercial emulsifiers available, Mitsubishi's Ryoto Sugar Ester Emulsifier stands out as the superior choice as a plant-based emulsifier that improves texture by forming micro-emulsions with ice cream’s milk fat, resulting in a smooth, fine texture devoid of any greasy after-effects. Moreover, specific grades of Ryoto Sugar esters are available to cater to your ice cream’s specific formula and processing procedure, ensuring that it will be able to withstand temperature changes every step of the way, including storage and transport.
In short, stabilisers and emulsifiers are absolutely essential in giving commercially made ice cream its creaminess, firmness, and durability, creating a convenient way for us to continue enjoying our favorite frozen treats whenever we want.
Want to learn more about how you can benefit from our high-quality, research-proven curdlan and Ryoto Sugar Ester emulsifier? Contact us to start elevating your frozen sweet treats today.
References
Homemade vs Store-Bought Ice Cream. Choice. https://www.choice.com.au/food-and-drink/dairy/yoghurt-and-ice-cream/articles/homemade-vs-storebought-ice-cream#:~:text=Texture%3A%20Most%20people%20said%20the,thing%20depending%20on%20the%20person.
Lu, J.; Pua, X.-H.; Liu, C.-T.; Chang, C.-L.; Cheng, K.-C. The Implementation of HACCP Management System in a Chocolate Ice Cream Plant. J. Food Drug Anal. 2014, 22 (3), 391–398. DOI: 10.1016/j.jfda.2013.09.049.
Ice Cream: The Science of the Sweet Treat. Compound Interest. https://www.compoundchem.com/2015/07/14/ice-cream/.
Szekalska, M.; Puci?owska, A.; Szymańska, E.; Ciosek, P.; Winnicka, K. Therapeutic and Industrial Applications of Curdlan With Overview on Its Recent Patents. Front. Nutr. 2021, 8, 646988. https://www.frontiersin.org/articles/10.3389/fnut.2021.646988/full.