HOW DO I KEEP MY SOFT DRINK PRODUCTS SAFE?
Bacteria, yeasts, molds and other organisms can be found everywhere, even in soft drinks. They can find their way into the process through raw materials, sweeteners, the facility environment, even on packaging materials.
Even though soft drinks might seem like a nutrient rich environment attractive to microorganisms, low pH drinks with high carbonation levels will kill most bacteria that get into the final package. A few bacteria may survive, but are usually inhibited from growing because of the harsh environment.
Soft drinks that are not carbonated and have less acidic pH levels, such as sports drinks or flavored waters, lack protection against spoilage organisms. Therefore, barriers such as filters should be installed to block contamination of the drinks by bacteria and other organisms.
Organisms of Concern
Yeasts are the most common organism found in carbonated beverages, because they can tolerate low pH and carbonation. Molds cannot grow in carbonated beverages, but may be found in sports drinks and other non-carbonated drinks. Bacteria can also contaminate soft drinks, especially those having some natural fruit juice as an ingredient. In particular, lactic acid bacteria (LAB) can be carried by the fruit juice into the process. Even non-carbonated drinks that are pasteurized can have thermo-acidophilic bacteria (TAB) remain in the product and cause spoilage.
The most critical filters in figure above are the final, “Sterilizing” filters (housings marked 4). These filters remove the target organisms. The goal is to remove whatever might create flavor, aroma or safety issues while also preserving the flavor and aroma of the final product.
The filters used to capture microorganisms are almost always membrane filters with pore size ratings of 0.45 microns or 0.22 microns. Processors may choose the smaller pore size to assure capture of all bacteria, including the vegetative forms of some species, but there is a risk that some flavor or aesthetic elements of the product will also be captured by membranes with 0.22 micron pores. For that reason, 0.45 micron membranes are used by many bottlers.
Read more about bacteria control in soft drink production in the Application Summary - "Bacteria Control in Soft Drink Production".