Protein powder and dietary supplements

The manufacture of protein powders and food supplements places high demands on industrial mixing technology. Different particle sizes, widely varying bulk densities, sensitive active ingredients and, in some cases, very small dosing quantities must be reliably processed into a homogeneous end product. At the same time, manufacturers expect short mixing times, reproducible results, flexible production options and a hygienic plant design.

Whether it is whey protein, plant-based protein blends, creatine, electrolyte powders or complex vitamin and mineral formulations: the quality of the end product is largely determined by the mixing process. Modern mixing systems must therefore do far more than simply blend powdered raw materials.

One of the greatest challenges in the manufacture of food supplements is the uniform distribution of ingredients with varying dosages. Whilst proteins often form the main component of a formulation, vitamins, trace elements, sweeteners, flavourings or functional additives are sometimes used only in very small quantities.

Added to this are significant differences in the physical properties of the raw materials. Fine powders with a low bulk density behave differently during mixing than coarse-grained, compact or poorly flowing components. These differences can lead to uneven distribution or segregation.

Formulations containing micronutrients are particularly challenging, as even slight deviations in concentration can affect product quality. It is therefore not only the intensity of the mixing action that is crucial, but also controlled product handling, ensuring that as many components as possible are reliably incorporated.

Mixing quality can be assessed, for example, by analysing representative samples and determining the coefficient of variation. For components added in small quantities, a suitable pre-mix may also be advisable. A high-performance mixing system must not only achieve a high degree of homogeneity, but also ensure that this is reproducible across different batch sizes and varying formulations.

Alongside dry powder mixtures, formulations containing liquid additives are becoming increasingly important. Liquid flavourings, vegetable oils, lecithin or functional ingredients are used, for example, to specifically influence the taste, processing properties or composition of a supplement. The uniform incorporation of such liquids into a powder mixture is technically challenging. Uncontrolled addition can lead to localised excess moisture, agglomerates and sticking. Fine or hygroscopic powders, in particular, are sensitive to uneven liquid distribution.

It is therefore crucial that the liquid is introduced in a metered manner into a sufficiently agitated powder bed. Suitable dosing systems and a tailored mixing action support distribution and reduce the risk of unwanted clumping.

In certain applications, however, targeted agglomeration may be expressly desired. For example, the wettability, dust behaviour or handling properties of instant powders can be improved through the controlled addition of liquid and subsequent process steps. This means that the mixer is not only used for homogenisation, but also performs additional process engineering tasks.

When processing protein powders and food supplements, the hygienic design of production facilities is of particular importance. Frequent changes to formulations, raw materials containing allergens and highly concentrated ingredients place special demands on the cleaning process. Even small amounts of residue from a previous batch can cause undesirable cross-contamination in subsequent products.

A mixer designed to meet hygiene standards should therefore have as few hard-to-reach areas as possible. Smooth surfaces in contact with the product, good accessibility and a well-thought-out discharge system facilitate cleaning and reduce the effort required between two production batches. Depending on the product and the plant design, different cleaning methods may be suitable. For dry powder products, suitable dry cleaning may be advantageous. For other applications, wet cleaning is recommended, supported where necessary by automated cleaning systems.

Following wet cleaning, it is essential to ensure that products are thoroughly dried, particularly in the case of moisture-sensitive items. Good cleanability is therefore not only a matter of hygiene, but also a key factor in cost-effectiveness. Shorter cleaning and changeover times increase plant availability and facilitate flexible production with frequently changing recipes.

Various mixing technologies are available for the manufacture of protein powders and food supplements. Their suitability depends largely on the physical properties of the raw materials, the composition of the formulation and the requirements of the product in question.

Whilst some systems are designed for intensive and rapid mixing, others prioritise particularly gentle product handling or flexible batch management.

Table 1: Comparison of industrial mixing systems for protein powders and food supplements

There is no single ‘best’ mixing technology. The key factor is the interplay between the formulation, process requirements, plant geometry and operating conditions. Particularly in the case of complex supplement formulations, it makes sense to evaluate the mixing technology using real raw materials and practical mixing trials.

The selection of a mixing system should therefore always be based on a holistic assessment. In addition to mixing quality and product protection, liquid addition, discharge behaviour, cleanability and energy requirements are important decision-making criteria. Practical mixing trials using original formulations provide a sound basis for this. In doing so, it is important to examine not only the homogeneity of the finished mixture, but also the behaviour of the product throughout the entire mixing and discharge process.

Table 2: Key parameters for evaluating and optimising the mixing process

The production of high-quality protein powders and food supplements requires a precisely coordinated interplay between raw material properties, mixing methods and process control. Reliable homogenisation of ingredients added in small quantities, gentle processing of sensitive components, the controlled incorporation of liquids and hygienic plant design form the basis for reproducible product quality.

With its spherical mixing chamber, inclined mixing axis and independently controllable mixing tools, the GloMix Glaxiaris® meets these requirements and opens up new possibilities for efficient and flexible mixing processes.

Mischer