4 challenging ingredients in soft drinks and how to mix them

Among the hundreds of ingredients used in today’s soft drinks, we highlight some of the most difficult ingredients to discharge, dissolve or disperse. 

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Lumpy powders

You may be surprised just how much physical energy can go into making energy drinks! One of the key ingredients is taurine that usually comes in 25 kg sacks. Taurine is notorious for forming into lumps especially if the sacks have been stacked on top of each other. In a soft drinks factory, you may see operators swinging these sacks over their shoulders and smashing them onto the wall or ground to break up the lumps inside. Lump breaking can be back-breaking work!

Another practice not to be recommended is to break up the lumps with a hammer after the lumps have entered a hopper in an effort to stop them clogging up the feeding system. Needless to say, this practice can damage stainless steel equipment and is time-consuming work for operators.

There is one mixer that offers you a neat solution for lumpy powders: Tetra Pak® Mixer RJCI 4X uses its large hopper with a large hatch of 50 cm by 40 cm to dissolve lumps easily. The hopper can be switched from dry to wet feeding mode where it fills up automatically with liquid in circulation from the mixer tank. When the lumps are dropped into the liquid, they begin to dissolve immediately before they can clog the system; no need for manual intervention with risks for health and safety. And at the end of the cycle, it’s simple to empty the hopper and switch to dry mode.

Dusty powders

According to our calculations, about 1% of the powders mixed into soft drinks never actually make it into the final drink. They end up in the air because when you discharge a powder into a hopper, dust is generated. A proportion of this dust usually escapes into the atmosphere and is sucked into an extractor fan where it is lost in the filter.

As an example, if 0.8% of a powder goes into the air and 100 kg of powder are being discharged an hour for 8 hours a day, 330 days a year, this adds up to losses worth 21,530 euros at a price of 10 euros per kg of powder. This is an average price for powders but very fine powder ingredients such as vitamins, flavours and colours with a greater tendency to form dust can be much more expensive.

To solve the dust problem, we have come up with the innovative Extraction and Recovery System (ERS) for which a patent is pending. With ERS, there is no release of dust, no ingredient loss and no filter waste. In fact, all the dust is recovered and goes back into the mixer. With this optional system, you aspirate powder dust from inside the feeding hopper and wash it with a small amount of water (18-25 litres) into a reservoir. From there it can be recovered into the recirculation stream as a mixture of water and dissolved powder dust.

The complete system is flooded and cleaned during CIP to ensure high hygienic conditions and food safety. So you can maintain the cleanliness and hygiene of your mixing line while reducing losses of powder ingredients and keeping the working environment free from dust.

No competitor can offer a mixer where airborne dust is captured and recovered. It is a unique option with our new Tetra Pak Mixer RJCI 4X.

Sticky gums

Gums act as stabilizers and give soft drinks more mouthfeel. Pectin is a typical example and is known for giving fruit jam its jelly-like quality. Other similar ingredients are CMC, xanthan gum and guar gum. The conversion of these powdered ingredients from the solid to the liquid phase can be troublesome because they resist wetting out. 

Within about 10 seconds of coming into contact with liquid, most gums start to thicken. In the worst case, they can form agglomerates called “fish eyes” with tough liquid gum on the outside but dry gum powder inside. Such agglomerates are difficult to mix effectively once formed.

Aware that time is of the essence, we have developed a mixing system for gums that is so fast that the gums disperse and dissolve before they have time to form fish eyes. The solution is called the Auto Mixing Device (AMD) and is available as an option with our new Tetra Pak Mixer RJCI 4X. Within seconds of the dry gums being mixed with water, they are sucked in by an injector and drawn through the AMD by a recirculation pump where a massive shear force is applied. With this solution, there is no need to install a high shear pump, which would work out about five times more expensive to buy than the AMD option. Our AMD can handle gum concentrations up to 1% of the final beverage at a temperature of 20°C, which is well within the usual range of gum concentrations of 0.2–0.4% for the final beverage. So there is no need to upgrade this mixer with an inline high shear pump when you choose the Auto Mixing Device as a high shear zone. It performs the same function but at a lower investment cost and using a lot less energy.

Gooey honey and thick concentrates

A few producers of premium soft drinks are using honey as a natural sweetener. Composed of 38% fructose, 31% glucose and 1% sucrose as well as 9% other sugars, honey is the only natural sweetener that requires no additional refining or processing. A golden gift from bees but due to its consistency, honey is not easy to add to a recipe unless you have the right type of mixer and lance. So how do you discharge viscous ingredients like this from a drum using a liquid lance?

Our answer is using water injection technology available with the large liquid lance of Tetra Pak Mixer RJCI 4X. Water fluidizes viscous ingredients locally at the suction head of this lance so they flow faster. Only a small jet of water is injected, which is monitored so that the amount can be taken into account when following a recipe.

Unless it is set honey, the viscosity of liquid honey is about 10,000 cP at room temperature (around 21°C). Some fruit concentrates such as mango paste can also have a consistency similar to honey. In trials, a concentrate with a viscosity of 5,000 cP flowed at a rate of 1,500 l/h when no water was injected at the head of the lance. However, when 5% water was injected, the flow rate increased to 2,200 l/h  ̶  an increase of almost 50%. This water injection technology is an efficient way of discharging even the most difficult thick pastes up to 10,000 cP.

Handle all these ingredients and more

Type of ingredient Soluble under regular working conditions Soluble with increased dissolving temperature and reduced dosing speed
Maltodextrin X  
Sugar X  
Dextrose (Glucose) X  
Liquid honey X  
Citric acid X  
Sodium citrate X  
Benzoate X  
Caffeine X  
Tea powder X  
Taurine X  
Aspartame X  
Pectin XX X
Caseinate   X
Starch   X
Xanthan gum XX X
Cocoa   X
Fruit concentrates XXX  

X = Possible  

XX = Possible for 1% concentration and 20°C dissolving temperature   

XXX = Possible for fibre length up to 10 mm

The table shows key examples of the ingredients our new Tetra Pak Mixer RJCI 4X can handle. This list could be extended but it should give an indication of the variety of different ingredients this new radial mixer can discharge and mix. It is important to note that the batch viscosity (not the ingredient viscosity) must be kept below 200 cP, which is not a limitation in the production of soft drinks.