Fruit juices are very safe food because of their high acidity, it is not possible for bacteria to shelter and multiply. However, there are still some bacteria that develop under the pH value 4,5 in fruit juices. These are heat-resistant, high acid-loving vesporous bacteria. These bacteria of the genus Alicyclobacillus lead to degradation of acidic juices protected by pasteurization, especially fruit juices.

With the years of 1980, such bacteria have caused significant material losses in the world fruit juice trade. Alicyclobacillus group bacteria are three species in itself:

• Alicyclobacillus acidocaldarius bacteria can grow at 60.
• Alicyclobacillus acidoterrestris bacteria can grow at 50.
• Alicyclobacillus acidocaldarius bacteria can grow at 40.

The most important of these are alicyclobacillus acidocaldarius bacteria.

Alicyclobacillus acidoterrestris bacteria cause the deterioration of smell and flavor in fruit juices such as oranges and apples and fruit drinks. The deterioration of odor and turbidity in alicyclobacillus acidoterrestris bacteria was first observed in the apple juices produced in Germany for the first time in 1982 and deteriorated during long storage in a hot period.

In standard analyzes, fruit juice is first pasteurized and then stored in a medium at high temperature and low pH. The presence of bacteria is detected by this method, but different analyzes are required in advanced laboratories to determine the bacterial species.

In the authorized laboratories, microbiological analyzes are carried out for the determination of alicyclobacillus acidoterrestris bacteria in fruit juices. In these studies, no heat treatment is applied to the sample, self-enrichment is made, after centrifugation, 24 is kept for hours and color change is observed in carbon dioxide detector and alicyclobacillus bacteria species are detected. During these studies, the relevant legal regulations and the standards issued by domestic and foreign organizations are complied with.