Manufacturing processes Processing & technology

CO₂-extracted oils are obtained using supercritical carbon dioxide. Under pressure, the carbon dioxide reaches a supercritical state and can therefore be used as an extraction solvent for the oil constituents.

This physical process allows comparatively moderate temperatures to be used. As a result, the oils are subjected to less thermal stress during extraction than with some other manufacturing processes. The CO₂ is then removed again; with proper process control, no residues of the extraction solvent remain in the oil.

CO₂ extraction reduces the fat content of the product to approx. 2%. The CO₂ used is biogenic and is generated during the production of bioethanol fuel from plant material. The amount used corresponds to the amount of CO₂ that the original plant removed from the atmosphere during its growth; only this amount is released again in the extraction process.

The CO₂ used is non-toxic, has GRAS status (Generally Recognized As Safe) and can be used in food without restriction. The extracted products can be used without further post-processing.

Deodorisation is a sub-step of refining. The oil is treated with steam to remove undesirable odour and flavour substances. A deodorised oil is therefore low in odour and taste. As it is not a chemical process, deodorisation is also permitted for organic oils.

In extrusion, a raw material is processed in an extruder under heat, pressure and mechanical shear and then pressed through a shaping die. In this way, protein flours can be turned into products with a new structure – from crunchy crisps to fibrous, meat-like textures.

Dry and wet extrusion

In dry extrusion (low-moisture extrusion), comparatively little water is used. This produces expanded, dry products such as crisps, cereals or textured plant proteins (TVP), some of which are rehydrated before further processing. In wet extrusion (high-moisture extrusion, HME), considerably more water is used and the mass is cooled in a cooling die. This creates fibrous, juicy structures that come particularly close to meat.

How our Heliaflor® extrudates are made

1. Mixing: Sunflower protein – pure or combined with rice flour – is mixed with water to form a dough-like mass.
2. Heating and conveying: The mass is heated in the extruder and conveyed through a barrel under high pressure.

Expanding and shaping: On leaving the die, the heated mass expands and takes on its characteristic shape and structure.

In this processing step, the press cake is finely milled in the absence of oxygen at very low temperatures using a gentle process (kryonert®). This process and the special surface structure the product acquires prevent any reaction with potential reactants such as atmospheric oxygen. As a result, the protein does not turn rancid despite its residual fat content.

The term ‘cold-pressed’ means that the oil has been obtained by pressing without the application of external heat and then filtered. It is neither refined nor deodorised. The term gives no precise indication of the temperature actually reached.

Cold-pressed oils have a limited shelf life and – with a few exceptions – should not be heated to high temperatures.

In the first step, all proteins and flours are gently partially de-oiled by mechanical pressing of the raw goods. In this so-called cold pressing, no additional external heat is applied, in order to preserve valuable constituents such as vitamins.

As a result, the proteins have a limited shelf life and – with a few exceptions – should not be heated to high temperatures.

For microbial reduction (Bactosafe), the raw protein is treated in a pressure chamber that can be hermetically sealed. Depending on the product, residence times during steam treatment range from 39 seconds to 15 minutes, at temperatures of up to 140 °C.

The right combination of temperature, steam and time achieves the desired microbial reduction. This ensures product safety and at the same time extends storage life.

A macerate, also known as an infused oil, is produced by maceration: fresh or dried plant parts (botanical raw materials) are steeped in a carrier oil such as olive, sesame or sunflower oil. Extraction usually takes place over several weeks at temperatures of 25 to 40 °C.

Depending on the raw material, dried or fresh plant parts are used. Calendula and arnica flowers, for example, are processed dried, while St John’s wort can be macerated as a fresh herb.

Mainly lipophilic, i.e. fat-soluble, constituents pass into the oil – such as essential oils, fat-soluble vitamins, phytosterols, carotenoids and other secondary plant compounds.

Our range includes:

• Calendula macerate
• Arnica macerate
• St John’s wort macerate
• Carrot macerate
• Amla and ashwagandha root macerates
• Aloe vera oil macerate

The macerates are gently filtered to ensure good product quality and suitable processing properties. Details of the exact composition, the carrier oil used and the INCI can be found on the respective product page.

Extracting protein from starch crops such as peas or rice requires – as the name suggests – water. Soaking the raw materials makes the proteins soluble so that they can be separated or washed out in several further steps. In this wet process, the protein content is increased through natural separation processes and, above all, without the use of additives.

Protein isolates are more highly purified than protein concentrates. During their production, many other components are removed in addition to oil or starch. The end product therefore consists very largely of protein – usually more than 80% of dry matter.

Typical process (wet fractionation)

1. Preparing the raw material: The seeds or pulses are cleaned and milled. For oilseeds, the oil is removed first.
2. Dissolving the protein in water: The flour is mixed with water. At a suitable pH, a large proportion of the protein dissolves in the liquid.
3. Separating insoluble components: Starch, fibre and other insoluble components are removed.
4. Precipitating the protein: The pH is adjusted so that the protein is barely soluble. It precipitates out of the liquid and can be separated off.
5. Washing and drying: The protein fraction is washed and then usually spray-dried. This produces a fine isolate powder.

The exact process depends on the plant. For soya, alkaline extraction followed by precipitation is widespread; for peas and other pulses, comparable principles are applied.

Protein concentrates are produced by removing non-protein components, which increases the relative protein content. For pulses, dry fractionation by air classification is usually the main method; for oilseeds, de-oiling the raw material is the decisive process step.

Oilseeds: de-oiling as the central step

Sunflower kernels (Heliaflor®) and soya contain a high proportion of oil in addition to protein. To produce a protein concentrate, the oil is therefore first removed by mechanical pressing, by extraction (e.g. with CO₂ or ethanol) or by a combination of both methods. This yields press cakes or de-oiled flours in which the protein is relatively enriched.

The protein content and quality of the concentrate depend, among other things, on how completely the oil is removed, how much hull material remains in the product and the heat and other process conditions to which the material is exposed.

Pulses: fractionation by air classification

Peas and faba beans are cleaned and milled into flour. This flour is then usually separated by particle size and density using air classification. The finer particles are typically richer in protein and are separated off as the protein fraction, while the coarser particles contain mainly starch.

Dry fractionation requires little water and largely preserves the properties of the proteins. However, the achievable protein content is limited and depends on factors such as the composition of the raw material, the degree of milling and the process conditions.

Quality characteristics

Protein content alone does not fully describe the quality of a concentrate. Amino acid composition, digestibility, solubility and functional properties are equally important. In the dry fractionation of pulses, the proteins often remain comparatively unchanged; in oilseeds, de-oiling and further processing can influence the functional properties.

Protein hydrolysates are proteins that have been deliberately broken down into smaller components. In the process, the long protein chains are partially or extensively split into shorter peptides and free amino acids.

How are they produced?

1. A protein raw material is mixed with water.
2. Enzymes split the proteins at specific points. Less commonly, the splitting is carried out with acid or alkali.
3. The reaction is stopped as soon as the desired degree of hydrolysis is reached.
4. Depending on the product, unsplit components are separated off and the hydrolysate is then dried.

Soya, peas, wheat or other plant proteins, for example, can serve as raw materials. Protein isolates can also be further processed into hydrolysates.

What changes as a result?

As a result of hydrolysis, the protein components are smaller and can dissolve and behave differently from the original protein. The properties depend heavily on the extent of hydrolysis and the enzymes used. Hydrolysates are used, for example, in beverages, soups or special foods. However, hydrolysis does not automatically guarantee better digestibility or a health benefit. It can also produce a bitter taste, which manufacturers can limit through the choice of process and further processing steps.

Distinction: Concentrates and isolates are produced mainly by removing other components. In a hydrolysate, by contrast, the protein itself is broken down into smaller peptides and amino acids.

Refined oil is virtually odourless and tasteless, making it highly suitable for formulations in organic and natural cosmetics. Refined organic oils are produced by mechanical pressing followed by physical refining. Only processing aids approved under the EU organic regulation are used.

For all unprocessed and further processed oils, there is another purely physical process: winterisation. The oil is cooled to 5–15 °C over a certain period. In this temperature range, wax crystals form, which are then filtered off.

The advantage: the oil stays clear even at low temperatures, e.g. in the refrigerator.