Deodorisation of fats and oils is necessary to remove the undesirable flavour and odours that are naturally present or that are created during their processing.
In the application of vegetable oils, deodorisation is commonly the final processing step in their production. These oils are often subject to either chemical or physical refining and have gone through various processing steps that may include: degumming, neutralizing, dewaxing, decolouring, washing and filtration steps prior to deodorisation.
Deodorisation involves processing the edible oils and/or fats in such a way as to remove the components that impart the undesirable odour. The components removed include free fatty acids; compounds such as aldehydes, ketones, alcohols and hydrocarbons; and various compounds formed by the heat decomposition of peroxides and pigments. In cases where an earth filtration system has been a processing step the unwanted earthy flavours can also be removed.
In the application of deodorising fish oils, more and more companies are using fish oils as dietary supplements and adding them to create functional foods that are high in nutritional value. However, no one wants to eat bread or drink milk that has a fishy flavour. Food manufacturers are therefore concerned about the organoleptic qualities of their fish oils in order to avoid consumer complaints and possible rejection of the product. Deodorisation of fish oils is therefore becoming a growing concern as use of fish oils as a supplement in other foods is increasing.
FT Technologies offers its high vacuum short path distillation system for the deodorisation of oil. This system is based on its unique RM series Centritherm® evaporator that gives a number of advantages over traditional short path or steam stripping units.
These include:
Very thin film - The Centritherm evaporator uses centrifugal force to create a thin film. The film developed is much thinner and more evenly distributed than traditional wiped film evaporator units.
Short residence time - The use of centrifugal force to evenly distribute a thin film results in residence times on the heating surface of typically less than one second.
Low thermal impact - Due to the very short contact time with the heating surface the thermal impact on heat sensitive products is minimal.
Suitable for "short path" and "molecular" distillation - The unique design of these units makes them suitable for short path operation. The internal condenser is designed to reduce the distance that the evaporated molecules travel before contacting the condensing surface to a few centimetres. Product surfaces are easily inspected and validated (GMP).
Compact, modular, flexible unit - The RM series Centritherm thin film evaporation units are constructed as compact modular systems, complete with supporting pumps, pipe work, electrical and control systems. The modular design allows for easy installation of the units in parallel or in series to suite specific applications, particularly where multiple separation steps are required to isolate a particular compound.
The high heat transfer coefficients developed in the Centritherm evaporator lead to greater evaporation rates per unit area than for other types of units. They offer substantial advantages over other thin film evaporation systems, such as wiped film, in terms of size.
The short path RM series Centritherm evaporator is an ideal system to refine and deodorise vegetable and fish oils. The system as shown in Fig 1 uses two stages.
Stage 1: Usually referred to as the degassing stage. It very efficiently heats the oil from the feed temperature to the operating temperature by way of the thin turbulent film. At the same time any moisture, dissolved gasses and some short chain free fatty acids are removed to allow the second stage to operate at high vacuums.
Stage 2: Is a short path unit that operates at high vacuum. It evaporates the free fatty acids and other molecules that contribute to the odour of the oil leaving a bland refined oil.
FT Technologies can supply suitable processing equipment to suite a range of production requirements from a simple batch operation to a fully integrated, continuous processing line.
The RM series Centritherm evaporator can also be used for:
- Refining and degassing of oils.
- Removal of pesticides from oils
- Removal of excess ethanol and FFA’s in Omega-3 processing.
Click here to find out more about the Centritherm evaporator RM series technology.
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