Yoghurt is firm, creamy or liquid acidified milk products manufactured from pasteurized milk by use of thermophilic lactic acid bacteria. In order to increase the dry matter content of the yoghurt in line with the given local preferences (which vary around the world), the milk can be concentrated or powder can be added to obtain a fortification - or the milk can be concentrated by means of ultrafiltration (UF). Typical standard yoghurt is not heat treated subsequent to fermentation and does not contain binding agents.
The various types of yoghurt are characterized by their structural properties. In set yoghurt the gel is formed and cooled in the packaging itself. After filling into the package the yoghurt is moved to the incubation room – and once the yoghurt has obtained the right pH it is cooled rapidly in cooling tunnel prior to final cooling in cold storage. Subsequently, the yoghurt solidifies to a solid texture in its packaging.
The below processing parameters are general guidelines and should only be considered as such.
| Processing Sequence |
Process/Technology |
| 1. Processed Milk |
|
| 2. Dry matter standardization (SNF 11-13%) |
Fortification, evaporation or UF concentration |
| 3. Deaeration (0.7-0.8 barg at 70°C) |
PARAVAC module |
| 4. Homogenizing (220 barg at 70°C) |
Homogenizer module, Niro Soavi, NANOVALVE |
| 5. Heat treatment (95°C for 5 min.) |
Heat treatment, PHE Systems/VARITHERM |
| 6. Inoculation of starter culture (<20°C) |
Inoculation module |
| 7. Heating to fermentation temp. (35-45°C) |
Yoghurt heating module |
| 8. Fruit/flavor dosing |
Aseptic fruit mixing module |
| 9. Filling Cup filler/crating/palletizing |
|
| 10. Incubation/fermentation room (35-45°C) |
|
| 11. Cooling tunnel (rapid cooling to <20°C) |
|
| 12. Cold storage (cooling to 5°C) |
|