Trimming the Fat
July 1, 2007
Trimming the Fat
Every bakery looks for ways to cut costs without sacrificing the quality of its products. For today’s bakers, the distribution of ready delivered fats is one expense that can be trimmed through on-site processing. Why pay for crystallized margarine or shortening when you can produce your own?
Food processing solutions such as these are Gerstenberg Schröder’s bread and butter, so to speak. The Brendby, Denmark-based company has more than 175 years of combined experience and is internationally recognized for its high-quality machinery and processing lines, including complete compact silo fat processing plants.
Gerstenberg Schröder promises a number of benefits to processing your own fat. For one, you have better control over the consistency of the shortening and, thus, can enhance your end product’s quality. For another, operators can increase production capacity by reducing the time it takes to blend shortening into your product. In addition, companies can create more space in their warehouses because there is no more need to store boxes of cubed shortening.
Gerstenberg Schröder divides fat processing into four main areas: receipt and storage, processing, tempering and delivery to mixer.
Receipt and Storage
In stage one, blends consisting of several fats and oils are delivered in bulk either by truck or by train. They then are transferred via centrifugal pump into heated storage tanks. The tanks should be kept at about 5°C above the melting point of the fat blend through the use of a hot water jacket or coils in the tanks.
A pump transfers the blends from the storage tanks to the gear pump aggregate, where the product flow rate is measured by a mass flowmeter. Gases such as nitrogen can be injected into the product stream, typically on the suction side of the gear pump. The product then passes through a scraped surface heat exchanger to cool and crystallize it quickly in a “shock cooling” process. Types of crystals formed depend on the types of fat used, as well as the cooling temperature and speed.
After crystallizing, the ingredient is processed in a pin rotor machine that breaks it into uniform crystals, which then are forced through a homogenizing arrangement for final texturizing of the product and distribution of the gassy bubbles.
Should production stop for any reason, the product is conveyed through a plate heat exchanger for re-melting and then is returned to the storage tanks.
Once the product reaches the recipe profile parameters for temperature, gas volume, pressure and speed, it can be transferred to silos, where is it is tempered for 2 to 4 hours for final maturation of the crystal structure. The silos are jacketed for tempering and pressurized with compressed air or nitrogen so that the product is pressed down into a pump.
Delivery to Mixer
Next, the shortening is fed by a lobe- or gear-type pump that generates low shearing against it. Next, it’s conveyed through a straight tube mass flowmeter to continuous or batch mixers throughout the plant.
In many cases, the required mixing time for fat/margarine into the dough can be reduced because silo fat can be produced as a much smoother product compared to boxed shortening. In addition, the properties of silo fat are much more controllable than those of bought-in, pumpable shortening.
The Control System
When it comes to processing your own fat, Gerstenberg Schröder’s Logic process control system can monitor, visualize and record all of production with even the most diverse recipes and parameters. The GS Logic process control system starts and stops silo fat production automatically based on the content level of the tank. This guarantees consistent product quality within a short period of time, as well as minimal investment and production costs.