Case Study III: A dairy client experienced a batch incident of package swelling in yogurt products.

It can be determined that this accident must have been caused by one or more variables. The main problems with spoiled yogurt packages is gas production and alcohol smell. The following issues were identified after an on-site investigation by Klean technicians:

1. Leakage was detected in the plate heat exchanger of the yogurt sterilization unit.

2. The direct inoculation method of yogurt starter cultures presents potential risks and other associated issues.

Morphological characteristics of intestinal gas-producing bacteria：The cells exhibit a slender rod-shaped morphology, occasionally approximating a spherical form.

No fixed aggregation pattern exists.

Primary sources of contamination by intestinal gas-producing bacteria: personnel, water sources, equipment cleaning (CIP), and recontamination.

Microbial DNA tracing and swab analysis revealed that the yeast and Escherichia coli present in the product shared genetic homology with the microorganisms identified on the plate swabs.

The quality accident was conclusively attributed to the leakage points in the plate sheets.