Glossary

Guidelines for food processing systems

Consumers should be able to expect that strict hygienic standards regulate how their food is processed. Contaminated foods may be harmful.

3-A Sanitary Standards (3-A SSI) establish standards and guidelines for systems used to process foods. These standards are prepared in collaboration with health authorities and industry experts. The 3-A Sanitary Standards organisation was founded in the USA to create standards for dairy equipment and systems, and for production, processing, and packaging dairy products.

The hygiene guidelines require foods to be protected against contamination with germs or other contaminants. To do so, all contact surfaces must be able to be cleaned and/or sterilised. In addition, some components must be able to be removed easily for manual cleaning.

3-A SSI assesses the hygienic design of a system or of a company as a whole. If a company or a device passes the test, it will receive a certificate with a test mark. The guidelines used in the 3-A Sanitary Standards are recognised in many countries and by many food manufacturers.

The term agglomerate comes from the Latin word "agglomerare" and means "to connect firmly". An agglomerate is the accumulation of previously loose components to form a solid compound. In certain applications, agglomerates are intentional, for example in the case of tablets. They are produced by so-called press agglomeration, i.e. the powder (or granulate) is pressed into a defined shape by applying pressure. Build-up agglomeration is also a technical process in which granulate is specifically produced. An agglomerate is held together by weak forces such as Van der Waals forces or simple physical entanglements.

However, agglomerates are undesirable in many applications. They can lead to undesired results in mixing processes. Therefore it must be ensured that they are dissolved. If agglomerates are dispersed, they are crushed into primary grains.

By the way, you can already witness agglomerates in your own household. If the cocoa powder ends up in the milk, lumps are formed which do not dissolve even after long stirring.

Systems used to process foods, drinks, or pharmaceutical products must fulfil high hygienic standards, and therefore must be cleaned regularly and thoroughly. However, disassembling the production systems to clean the surfaces that come into contact with final products would be too complex and time-consuming. Therefore, such technical process systems are cleaned at their locations. This is called Cleaning in Place (CIP). To ensure that cleaning achieves the same results every time, CIP is a stipulated and reproducible process. Cleaning agents, pressure, temperature and application time are all clearly defined for each system. The individual steps used in the cleaning process may vary by product, however, cleaning always includes rinsing steps during which product and cleaning agent residue are flushed out of the system using clean media.

The cleaning process is controlled automatically in most cases. CIP is commonly carried out after a production run or before converting production to other products.

CIP has multiple advantages: It effectively avoids cross-contamination and product contamination. CIP reduces cleaning time and costs, and energy costs for CIP are relatively low. All industries benefit from having a cleaning process that is easy to control, so CIP ensures high hygiene standards can be maintained. Overall, CIP is a process that is easy to integrate with all operational procedures.

ystral machines and systems can be designed to work with CIP processes. Riboflavin tests, also called fluorescence tests, can be carried out to verify cleaning effectivity .

The word "homogeneous" means "of the same or a similar kind or nature". It has a wide range of application, it is used in natural sciences as well as in social sciences. In natural sciences, for example, one speaks of a homogeneous mixture when the components contained in the mixture are evenly distributed. In  natural sciences, the equality of a property over the entire extent of a system or the similarity of elements, objects and phenomena of a system is essential. The opposite of "homogeneous" is "heterogeneous". Here, too, the approach can be decisive: milk is heterogeneous at the microscopic level, where one can distinguish between fat and water, whereas at the macroscopic level milk is homogeneous. However, if the milk is left standing for a longer period of time, it can again become a heterogeneous mixture, because then fat (cream) and water separate. If you want to prevent this, you have to "homogenize" the milk. The process by which a substance or system is made homogeneous is therefore homogenisation.

Rheology is the study of the deformation and flow behaviour of matter. Of importance are viscosity, structural viscosity, dilatancy, thixotropy and rheopecty. A subarea of rheology is rheometry, in which rheological properties are determined by means of a measuring method. Among other things, the viscosity can be determined or how a fluid flows under shear.

Viscosity describes the resistance of a fluid or a gas to shear, under expansion or at uniform pressure. Solids also have a viscosity, but this is difficult to determine. Honey has a high viscosity, water a low one.

A distinction is made between Newtonian fluids with a linear flow behaviour and non-Newtonian fluids. Non-Newtonian fluids have a time or shear rate dependent flow behaviour, i.e. the viscosity changes under the influence of shear.

Knowledge of viscosity and flow behaviour helps to choose the right machine and its settings.