Analysis Request – Concentrates

Concentrates, described as fruit juices from which the water is extracted, are mostly used in the beverage industry to produce fruit juices and nectars, as natural sweeteners and to manufacture natural food colours. Even though most concentrates are filtered, evaporated, pasteurized, sometimes include additives, the high sugar content present may encourage microbiological growth.


Common spoilage bacteria in concentrates include Acetic Acid Bacteria strains, Lactic Acid Bacteria strains and Thermo-Acidophilic Bacteria. Vinlab Micro, therefore, offers Lactic Acid Bacteria Cultures specific for Lactobacillus and Leuconostoc, Alicyclobacillus Bacteria Cultures for Thermo-Acidophilic Bacteria, and Bacteria Cultures for broad spectrum quantification of bacterial species. Due to high sugar concentrations Osmophilic Yeast Cultures are performed. Grape concentrates, a common carrier of Zygosaccharomyces, can be identified by the Scorpion Yeast Panel.


The primary reason to test concentrates, as with most products when it comes to Microbiological analyses, would be quality control. When these micro-organisms survive and proliferate in concentrate products spoilage may occur. The chemical composition may be altered through fermentation, oxidation of ethanol, ethanol production and an increase in both acetic acid and acidity. Physical changes include finished products with a higher turbidity or a gummy-slime appearance. On the nose or palate a sour or off-taste, a butter milk off-flavour or strong butyric odour may be perceived. Quality control goes hand in hand with brand identity, ensuring only microbiologically stable products make their way into markets.

How often and when?

It is good practice to test products throughout the entire production process, particularly after treatments, proving efficacy. Vinlab Micro recommends testing products after filtration, evaporation, pasteurization and the addition of additives allowing swift action should target micro-organisms be detected. Testing products before distribution is beneficial when wanting to verify authenticity of products


Whether you’re making 100% fruit concentrates, concentrated fruit cocktails, beverages or punches, or powdered fruit concentrates ensuring the microbiological stability of your concentrate is essential.