How to maintain consistent dough quality in baked goods production

09.03.2016
from LT Food Medien-Verlag | Lebenmitteltechnik

Kneading in a precision process

New components have been added to the CODOS® continuous kneading system. These include a shear stream mixer, which is ideal for processing jobs that require dry material to be thoroughly mixed with liquids and carefully homogenized.Typical applications include baking operations involving flour, water, oil, yeast, pre-ferments and sourdoughs.

The CODOS® system has been part of the varied portfolio of Zeppelin Systems in Rödermark for several years, ensuring continuous dough production and offering a whole host of benefits for the baking industry. The main advantage it offers is consistent dough quality coupled with relatively low energy consumption.Another feature to recommend the system is that it is easier to adjust and control process parameters compared with batch kneaders,

though ultimately the critical argument in support of continuous processing simply concerns better dough quality. In batch kneaders, batches are produced consecutively, which means small variations between batches can arise in the measuring of the raw materials. Furthermore, note that the dough fermentation process begins immediately after its removal from the kneader – all batches are generally not immediately processed in full, but gradually added to the dough preparation system, meaning that the various portions of dough to be processed are at different stages of maturity. This can be avoided by continuous kneading followed by the direct feeding of dough to the downstream processes.

A second advantage is energy efficiency: In batch kneaders, much more mechanical energy is added to the dough, with a large part of this converted into thermal energy. Compensating for this effect and maintaining a constant temperature requires a high level of energy input. In the CODOS® system the dough remains at a broadly constant temperature from start to finish, thanks to the cooled/heated double-jacket design. Solutions in advance would be the use of a flour cooling unit or the use of brine at sub-zero temperatures. Appropriate design can mean energy savings of 30% compared with conventional kneading processes. These are not least achieved by means of the process parameters that can be set with greater precision. The measured addition of decorative products such as currants, nuts, or chocolate flakes during the batch process is often difficult, as they have a tendency to split, crumble or melt during kneading. To counter this problem, the open workings of the CODOS® system facilitates the flexibility of adding loose ingredients at the end of kneading, and to incorporate them without crushing thanks to the gentle action of the kneader.

Continuous dough production is still a relatively recent production process, making it all the more vital that producers are aware of the general process parameters. For this reason, Zeppelin Systems has spent many years running continuous dough processing trials with the Institute for Cereal Processing (IGV) in Nuthetal near Potsdam, where the CODOS® mixing and kneading system is available for customer trials. Recently, new components have been developed to enhance the prospects of the successful system principle, including the ShearDos WIP shear stream mixer with optimized cleaning process.WIP stands for wash-in-place. The new DymoMix has been designed primarily for the production of light doughs such as pasta and waffle doughs, or pre-ferments. Both mixers can be easily integrated into the CODOS® system. The new ShearDos WIP, which can be integrated into batch or continuous operation, is ideal for processing jobs that require dry material to be thoroughly mixed with liquids and carefully homogenized. Target users could include baking operations that mix flour with water, oil, yeast, and pre-ferment or sourdough cultures.

The great advantage of this mixing principle is that the raw material properties are not destroyed, but can also benefit the mixture. Less than two minutes of kneading is required to create an homogeneous product that is perfect for further processing .The powdered components are continuously fed into the shear stream mixer through a flanged stud in the lid. Measured liquids such as water and injected sourdough or yeast solution are simultaneously administered through connection studs on the side. The mixing tools, which operate according to the rotor-stator principle, thoroughly mix the liquid/solid mixtures by applying shear energy. DymoMix promises further improvements to dough quality, ensuring that flour and other dry materials are properly wetted before adding them to the dough production process. In contrast to conventional systems, wetting is not performed through high pressure but by centrifugal force.

This means that even the addition of very small amounts of moisture can create an outstanding product such as high-quality dry pasta dough (dough yield (TA) of 136 from 100 parts of flour), which can be processed immediately with no intermediate steps. The DymoMix handles all standard dough types with different moisture contents (dough yields (TA) of 110 to 250 from 100 parts of flour); dry materials used include flour as well as premixes. Water and free-flowing solutions are ideal for wetting, and the wetting level can be easily adjusted during operation. An homogeneous dough is produced in just seconds, with the dough then fed immediately to the CODOS® kneader.