Struggling for resources, their exploitation and sustainment, food producers and processors have dedicated themselves to the question of how to offer plant-based alternatives that deliver the good of the milk. Soy, coconut and almond-based products have been on the market for some time, but mainly the use of oats has established a “mass-compatible product”. But how to use and transform it into an appealing product with the help of smart measurement technology? The special properties of the raw products in oat milk production require sensors that are flexible, robust and resistant to adhesion. But what to consider in each step of oat milk production?

The first step is separating the husks. This is done quite conventionally by peeling, sometimes the oats are immediately milled into flour or processed to flakes in the same step. If not directly processed further, the peeled oat grains must undergo a drying process to prevent any growth of the seedling inside. So far, treatment and processing  is similar to standard processes in bakery or brewery. Here, pressure sensors as PP20H and temperature sensors as PT20H are deployed. CleverLevel is the optimum solution to protect machinery against jamming or blocking. Available in either compact or field housing, the sensor will detect dry products, flour and spillage goods.

Sensor requirements increase while the process continues. After milling, the oat flour is dissolved in water and the actual production work begins. The mix of liquid, solid particles and the ingredients of table 1 is difficult to detect because adhesion quickly builds up and consistency varies. The point level sensor CleverLevel operating on the frequency sweep technology is the ideal product by ensuring safe switching operations. This technology allows for monitoring every container upon overfill and empty level. The Oat Milk, a Plant-Based Alternative sensors further protect pumps and tubes against damage by running dry.

Magnetic inductive flow sensors control enzyme dosage for carbohydrate breakdown. Here, precise CombiFlow PF75H flow sensor is the product to choose. The oat pulp is then temporarily stored in tanks to allow enzymes becoming active. Both when dissolve the grains in water and in tank fermentation, efficient enzyme work requires optimal temperatures. To reduce viscosity and to obtain the desired sweetness and mouthfeel, starch is being split up into glucose and isomaltose.

Consistent hygienic design is indispensable when it comes to tank cleaning. Front-flush temperature sensor TER8 is here the optimal choice. CleverLevel level switch featuring a very small contact surface also provides optimal capabilities for quick and efficient cleaning. Particularly when installed at the tank together with a Baumer Hygienic Connection (BHC). Integrated pressure sensors with flush membrane, either PFMH or PBMH, not only deliver high-precision signals but thanks to the BHC adapter are very easy to clean.

Once the enzymes have done their work, the situation becomes different. In the heat exchanger, prior to filtration, temperature control for appropriate energy intake requires quick measuring operations. Temperature sensor PT20H plays to its strength by featuring a T90 time of less than 1.1 seconds.

Enzyme activity is ended and the oat pulp is heated up to about 60°C for upcoming separation. As in conventional dairy industry, also here PT20H or TE2 temperature sensors are deployed for pasteurization temperate control at the heat exchanger, while pressure sensors PP020H measure differential pressure and flow sensor CombiFlowPF75H monitors flow rate and heat holding time. In both processes, hygienic sensor design plays a vital role.

Using a decanter any solid parts, mainly husks, are separated. This process step calls for the CleverLevel  sensor being particularly insensitive against adherence. Temperature and inlet pressure are crucial for proper decanter operation. For this reason, sensors with large DFON display like PFMH and TRFH from the CombiSeries are ideal products. Besides showing the measured values, the display will change color as soon the values are outside the limits.

The product is finished in the mixing tank adding liquid and solid ingredients. These are oils, lecithins, flavor carriers/fruit, vitamins, minerals and salt. Temperature and pressure are key here as well. The measuring operations are performed by TE2 temperature sensor and PFMH pressure with utmost precision. Particularly product variants with different fruit additions require a high level of flexibility in sensory analysis. Mixing tank full and empty signals are safe with the CleverLevel point level sensor. Potentiometric level sensor LSP is deployed for level measurement in tanks without mixers. The sensor measurements are not only extremely fast and precise which is particularly helpful in small dosing containers, but on top the sensor is very insensitive to buildup of deposits.

A homogenizing pump in the mixing tank is mixing up the ingredients. A high-pressure homogenizer is used to permanently bond them together and to ensure stable homogenization. In doing so, all individual product ingredients are brought into the same size. Like in a milk homogenizer, feeding temperature and pressure are being monitored. For mechanical pressure monitoring at homogenizing valves Baumer offers products of its Bourdon brand.

Now it’s all about the future of the nearly finished product. Permanent cooling required, or extended shelf life at room temperature? This question is answered by the related heating process. Both cold sterile filling with UHT treatment and standard pasteurization at 72°C are feasible.  The Baumer portfolio offers the right process sensor delivering all the signals required for heat exchanger control. In plate heat exchangers, further to fast temperature measurement with PT20H, particularly the magnetic inductive flow meter CombiFlow PF75H comes into play to define holding times, and also high-precision pressure sensors PBMH or PFMH detecting the differential Baumer Hygienic Connection (BHC): hygienic process adapter for optimal cleaning processes pressure to identify any cleaning requirements. Residual starch in the product tends to gelatinize, reason why now it turns out how effective previous enzymatic pre-dissolution was. Sometimes it is necessary to add another enzyme mixture in a second step. Fully converted to glucose, only “usual” burning along with fat and protein components will remain, which over time will impair heat transfer and call for cleaning.

The product now is ready to be filled in sterile tanks. It goes without saying that from now on hygiene  and a clean environment are crucial. This requires efficient cleaning cycles at both ends. Now, absolutely tight sensors in hygienic design with stainless steel housings and IP 69 protection or even protTect+ will pay off.

Manufacturers of oat milk products have an interest in saving water and energy, because they want to live their claim of sustainable alternatives. Fully automated CIP system are always the first option. Whereas they allow for a flexible number of tanks, they require reliable parameter monitoring according to Sinner’s circle. PF20H calorimetric flow sensor measuring flow velocity together with CombiLyz AFI inductive conductivity sensor suffice for easy solutions. They ensure safe cleaning cycles at fast changing phases.

Faster temperature measurements of PT20H and more accurate flow measurement with PF75H magnetic inductive flow meter improve such installations and further reduce water and energy consumption while saving time in parallel.

Sustainable manufacture of high-quality products at high safety level always implicates a successfully implemented hygienic plant design. The Baumer Hygienic Connection (BHC) with hygienic process adapters allows for top-level integration by front-flush sensor installation. The exchangeable O-ring seal directly within the process and protected by its fix center position, together with the clamp connection for steady pressure form the perfect process connection. Easy to weld in the tank, this process connection allows for fast cleaning free from any residues. Installed in pipelines, the process connection is capable of fast changing phases and helps minimize product loss, the use of detergents as well as water consumption.

Many of the components used in oat milk production are also used in other F&B processes. Oat milk is reputed to be a highly nutritious product, reason why it calls for stringent hygiene concepts as protection against microbiological impairments. The different phases of solid, pulpy and liquid texture require flexible measurement technology, particularly in filling and limit level monitoring. These processes operate on very precise parameters and depend on tight control. So, it is not a coincidence that Baumer has been a reliable partner ever since the beginning of successful production and international marketing of oat milk products thanks to smart solutions for safe production – even when being that demanding.