Which mixing tools are suitable for incorporating oils and fats into instant soup powder?
Suitable mixing tools for introducing oils and fats into instant soup powder
For introducing oils and fats into instant soup powder, internal mixing blades, cutting rotors, cutting heads, helical ribbons and paddle tools are suitable above all. What is decisive is that the mixing tool concerned moves the powder particles sufficiently and at the same time enables finely distributed, lump-free wetting with the fat phase.
Internal mixing blades
Internal mixing blades produce intensive product circulation and are well suited where the fat phase is to be worked uniformly into the bulk material. They support good distribution without loading the product unnecessarily heavily.
Cutting rotors
Cutting rotors are particularly useful where fat agglomerates have to be broken up or viscous constituents finely dispersed. They help to avoid lump formation and to introduce the fat phase quickly into the active mixing zone.
Cutting heads
Cutting heads are used above all where strong mechanical size reduction or the breaking up of build-up is required. They are helpful with formulations involving a higher fat addition or with products that tend to form agglomerates.
Helical ribbons
Helical ribbons convey the product in a controlled manner and ensure uniform blending with comparatively gentle treatment. They are particularly suitable where the fat is to be distributed with low mechanical loading.
Paddle tools
Paddle tools combine good circulation with comparatively gentle mixing behaviour. They are suitable where the fat phase is to be distributed but sensitive formulation constituents may be loaded as little as possible.
Important process engineering aspects
- Spray application: oils and fats should be introduced into the active mixing zone atomised as finely as possible via suitable nozzles.
- Temperature control: solid fats must be brought to processing temperature before dosing.
- Choice of tool: depending on the fat content, viscosity, particle size and product sensitivity, the mixing tool must be selected accordingly.
- Order of addition: the powder is usually charged first and the fat phase then added while mixing is running.
- Product sensitivity: with fragile constituents such as vegetable flakes, herbs or croutons, the tool should be chosen so that the fat is distributed first and sensitive components are introduced gently only later.
The optimum choice of mixing tool depends on the fat content, viscosity, particle size, batch size and desired mixing quality and should be validated in preliminary trials.
How amixon® introduces oils, fats and liquid flavourings into powders without lumps
The liquid is introduced at the point of highest mixing activity
The main cause of lump formation is local over-wetting. amixon® therefore doses oils, fats and liquid flavourings via an addition lance or two-fluid nozzle directly into the active area of the cutting rotor. There the rotor distributes the viscous phase microfinely, while the SinConcave®/SinConvex® helical mixing tool continuously conveys fresh, unwetted powder into the wetting zone. This produces a microfine addition of liquid in which the mixing chamber remains largely free of build-up. The two-fluid nozzle produces the finest atomisation and is also suitable for very small addition quantities, for instance with flavourings or oil-vitamin solutions.
Mastering viscosity in a targeted manner
The lower the viscosity of oils and fats, the more uniformly they wet. amixon® mixers can therefore be equipped with a temperature-controlled double jacket on request. Solid fats are thereby reliably kept above their melting point, without cold wall zones arising in which the product could solidify or stick. amixon® has many years of experience in wetting powders, particularly where the powders are left in a cold state. Large specific surfaces, capillary structures and heterogeneous particle surfaces determine the wetting rate. The dosing rate, the choice of nozzle and the mixing intensity therefore have to be matched to one another precisely.
A reproducible dosing strategy
A continuous, finely dosed addition can be stored as a mixing programme in the PLC. The mixing intensity is infinitely adjustable – from gentle moistening with low energy input through to intensive incorporation with rapid and complete distribution. The fill level can vary from approximately 10 to 100 % depending on the task, without substantially impairing the mixing quality.
Tool configuration and verification
Depending on the application, vertical mixers (VM, HM), SpherHelics® mixers, cone mixers (AM, with liquid addition optionally via a two-fluid nozzle) or continuously operating systems such as the AMK are used. The wetting behaviour, the oil binding capacity and the dosing profile are verified in advance by amixon® in the pilot plant with the original product.
For instant food, amixon® systems are proven in practice: these include twin-shaft mixers with automatic wet cleaning when changing between savoury and sweet products, the KoneSlid® KS specially for fragile, spray-dried and agglomerated goods, and the RMG for low-dust, rapidly soluble granules.
Hygienic design as the constructional basis
All the properties described rest on the amixon® hygienic design. The mixing chamber and mixing tool are welded free of crevices and ground smooth, and the mixing tool is mounted at the top only, so that the contamination-critical lower shaft passage is eliminated. Large Clever-Cut® inspection doors with a permanently dead-space-free OmgaSeal® seal provide ergonomic access to all product-contact surfaces. Dead-space-free discharge devices and integrated washing lances – on request with fully automatic wet cleaning – permit validatable dry and wet cleaning in accordance with the EHEDG guidelines, the FDA hygiene guidelines and the 3-A Sanitary Standards.