Nowadays the processing technology of whey is being mastered for obtainment of high added value products, e.g. whey protein. During the processing of whey, as a side product accrues whey lactose. The utilization of this product, without polluting the environment, is problematic. Therefore this unresolved issue allows developing technology of whey processing with sufficient profitableness.

Latvian company BALTIC DAIRY BOARD in year 2015 launched factory of whey processing and department of lactose processing. The company along with biotechnologists of Latvia, developed bioprocess for various whey, as well as whey lactose processing, where used yeast strains could efficiently uptake lactose as a substrate. As a result, yeasts for food industry were obtained. The given technology is successfully introduced in practice, and as the experts of the field admits, it is unique and gives an opportunity to obtain high added value product.

For the run of production fermentation process, technological line is used. It consists of bioreactors with volume of 35, 350, 4000 liters and two bioreactors with volume of 15 000 l. In all bioreactors, a novel type magnetic mixer (even in 15 000 liter bioreactor!) was used. Above mentioned system is fully closed and automated, the connections between bioreactors are provided by pipeline system and 4 membrane valve group. The system with membrane valve group provides sterile nutrition media and product transport, as well as pipeline and reactor cleaning and sterilizing.

Each individual bioreactor is equipped with a technological stand, to ensure automatic fermentation, cleaning, sterilizing, heating and cooling process. Local control of each bioreactor occurs via color touch screen display (9.6”). In this bioreactor control system Siemens Simatic S7-300 (ET200) controllers are used. Thereby the local control of each individual bioreactor is provided, apart from rest of the bioreactors.

Central cascade control system (CCCS) ensures connection between different bioreactors and CIP/SIP systems, as well as with computerized software SCADA. For this purpose more powerful Siemens Simatic S7-300 (S7-317) was used. The CCCS controls certain groups of valves depending on the selected recipe and the condition of the respective sensors in the bioreactors, as well as in the system CIP/SIP and pipelines (medium presence sensors are installed in the vent groups).

The central cascade control system directly controls the following processes in the selected bioreactors or pipelines: CIP cleaning, SIP sterilization, nutrition media feed, biomass (e.g. inoculum) transfer from one bioreactor to another, and bioreactor emptying. Before starting the process, new recipe must be selected or prepared. In each recipe, the movement rout of substrate, product, CIP solution and SIP steam is detected.