Methods of Microbiological Quality Control
Beverage pests such as Alicyclobacillus, fermentable yeasts and other juice spoilers can cause considerable economic damage. Modern quality control must ensure that these germs can be detected quickly, specifically and reliably. Nevertheless, methods that are over 100 years old and have serious disadvantages are still regarded and used as the gold standard.
| The cultural detection of microorganisms based on culture media is simple and inexpensive, but often unspecific and time-consuming. In addition, up to 99 % of all bacteria cannot be cultivated at all. | Quality control with VIT® gene probe technology: With VIT®, beverage spoilage organisms can be detected quickly, specifically and independently of their cultivability. Inhibitors in the sample material do not play a role. The bacterial cells remain intact during the analysis, which enables clear assignment of the signals and reliable quantification of the cells. | ||
| Molecular biological methods are fast, but the presence of inhibitors in the sample material and the detection of dead cells often leads to false-negative or false-positive results. |
The Advantages at a Glance
For over 20 years, companies worldwide have relied on our expertise and VIT® gene probe technology. Our customers include beverage producers, raw material suppliers, product testing groups and quality assurance institutes, who have been able to achieve premium product quality as well as numerous financial and competitive advantages thanks to the fast and robust detection process.
specific: accurate identification of bacteria regardless of their morphology or cultivability
fast: short detection time and easy handling
sensitive: low detection limit
only living bacteria: dead bacteria are not detected
robust : no use of enzymes that are susceptible to interference
universal: can be used throughout the entire production chain (raw materials, in-process control and end product control)
Quality Assurance at the Highest Level
Would you like to test fruit juices, concentrates, sweet drinks or raw materials for harmful bacteria? We offer a comprehensive service portfolio and a wide range of test kits for fast and specific in-situ quality assurance of the entire production chain - from the raw material to the end product.
Recommended VIT® Test Kits
VIT® Alicyclobacillus
Aseptic taste? This test kit quickly analyzes the bacteria of the genus Alicyclobacillus and Alicyclobacillus acidoterrestris.
VIT® Lactic Acid Bacteria
Do you suspect beverage spoilage? This test kit quickly analyzes the genera Lactobacillus, Pediococcus and Leuconostoc in beverage samples.
VIT® Spoilage Yeasts
Test kit for the rapid analysis of live obligate and potentially fermentable yeasts in still and carbonated beverages.
VIT® Leuconostoc/Lactococcus lactis
Test kit for rapid analysis of live Leuconostoc spp. and especially Lactococcus lactis. Suitable for hygiene and product samples.
Recommended Flow VIT® Test Kits
Flow VIT® Alicyclobacillus
Alicyclobacillus even faster and easier to detect - with the Flow VIT® Alicyclobacillus test kit. Simple operation and automatic evaluation of results.
CyFlow™ BrettCount
Test kit for the rapid and automated analysis of Brettanomyces bruxellensis (Dekkera bruxellensis) in wine production samples. Identification and quantification of vital Brettanomyces bruxellensis cells is available in a few minutes.
Flow VIT® Dekkera anomala
The CyFlow™ BrettCount test kit enables fast and reliable quality control at all stages of wine production.
Beverage Pests: Sensory Defects and Identification
The beverage industry is struggling with increasingly complex requirements for the production and quality assurance of fruit juices, concentrates and sweet drinks. Competitive pressure and growing consumer demands for product quality and diversity require an acceleration of the production chain and therefore flexible and efficient quality assurance.
Although germs that are harmful to beverages are not usually pathogens, they are particularly feared by juice producers. The reason: the sensory defects they cause can result in customer dissatisfaction and thus considerable damage to the company's image.
Alicyclobacillus
Alicyclobacilli are common thermophilic and acidophilic beverage spoilers that are able to form endospores. They cause sensory defects such as aseptic odor and taste. The most feared member of the genus is Alicyclobacillus acidoterrestris. Contamination usually occurs directly via fruit contaminated by the soil and thus via raw materials such as fruit juice concentrates or sugar syrup.
Acetic Acid Bacteria
Acetic acid bacteria only appear in non-carbonated beverages. As the name suggests, they cause an unpleasant vinegar tinge due to the formation of acetic acid, acetic acid ethyl ester and gluconic acid and a visible brownish discoloration in light-colored beverages (e.g. orange or lemon juice). Contamination with acetic acid bacteria is mainly secondary due to impurities in the production chain.
Lactic Acid Bacteria
Juice spoilers such as Leuconostoc mesenteroides, Lactobacilus paracasei, L. casei and L. perolens form diacetyl in carbonated beverages, cause a cheesy smell and increase the viscosity. In addition, lactic acid bacteria also form gas, which, as with fermentable yeasts, causes dangerous bombages to develop. The contamination often goes unnoticed at first. The sudden mass proliferation of bacteria usually only occurs when the batches have already been delivered.
Yeasts
Depending on their degree of fermentability, they are divided into strong fermenting, fermentable, weak fermenting and non-fermentable (respiratory yeast). The first two groups are particularly harmful and can even cause fermentable odours in carbonated beverages, undesirable off-flavours, clouding and sediment in clear beverages or clarification in naturally cloudy beverages. In addition, dangerous bombages can develop in already bottled beverages, destroying the container.
Mold
Molds grow in thin, slime-like coatings on the surface of the juice (biofilms). In addition to sensory defects such as mouldy and musty notes, they lead to clarification and/or color changes in the end product. Some molds also produce mycotoxins, which are toxic to humans to varying degrees. The product is contaminated by infected raw goods. The mycotoxin pulin, for example, can be found in the rotting areas of apples, pears, quinces, apricots, etc. It is considered a neurotoxin and can lead to vomiting and indigestion. Grapes infested by molds produce the mycotoxin trichothecin, which has a cell-damaging effect on humans.
Pathogenic Germs
The occurrence of pathogenic germs is mostly limited to products from the mineral water industry. This is mainly due to the low pH values of most fruit juices and carbonated or non-carbonated sweet drinks. Even if they are present to a small extent in the end product, most pathogens cannot multiply in this environment.
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