This document discusses two techniques for pasteurizing foods - HTST and UHT. HTST involves heating foods to 72°C for 15 seconds, killing pathogens but providing a shorter shelf life of 2-3 weeks. UHT involves heating to a higher temperature of 140°C for only 2 seconds, sterilizing foods and allowing for an even longer shelf life of 2-3 months, though it can impact color, flavor and protein structure. The document provides tables comparing the key details of each technique.

1. Presented by
Md. Monirujjaman
Daffodil International University
Department of Nutrition and Food Engineering
presentation topic
HTST & UHT technique

2. Pasteurization
 Pasteurization is a process, that
applies heat to destroy pathogens in
foods. For the dairy industry. Apply
heat to specific temperature and
specific time to destroy pathogenic
bacteria in food product. mainly its
apply to milk and beverage sector

3. Some different type of pasteurization
and there temperature
Temperature Time Pasteurization Type
63ºC (145ºF)* 30 minutes Vat Pasteurization
72ºC (161ºF)* 15 seconds High temperature short
time Pasteurization
(HTST)
89ºC (191ºF) 1.0 second Higher-Heat Shorter
Time (HHST)
90ºC (194ºF) 0.5 seconds Higher-Heat Shorter
Time (HHST)
94ºC (201ºF) 0.1 seconds Higher-Heat Shorter
Time (HHST)
96ºC (204ºF) 0.05seconds Higher-Heat Shorter
Time (HHST)
100ºC (212ºF) 0.01seconds Higher-Heat Shorter
Time (HHST)
138ºC (280ºF) 2.0 seconds Ultra Pasteurization
(UP)

4. HTST Pasteurization Technique:
 HTST is the most common
pasteurization technique in the dairy
industry. HTST stands for High
Temperature, Short Time. It is also
known as flash pasteurization. It is a
method of pasteurizing perishable
beverages like fruit and vegetable juices,
beer, and wine. This was first introduced
in 1993 and observed 99.99% reduction
of harmful bacteria. subjected 72°C (161
°F) for about 15 seconds in order to kill
pathogenic bacteria like Salmonella,
E.coli Escherichia , and Listeria.

5. HTST method step

6. UHT Pasteurization
Technique
UHT Pasteurization is also known as
Ultra-High-Temperature (UHT)
Pasteurization. This typically involves
heating milk or cream to 140 °C (284
°F) for 2 seconds. UHT is commonly
used in milk pasteurization but is also
can be used for fruit juices, cream, soy
milk, yogurt, wine, soups, honey, and
stews.

7. Basic Steps of UHT
Pasteurization
 Spraying the milk or juice through the
nozzles into a chamber filled high-
temperature steam under pressure
 After temperature reaches to 140 °C,
the fluid is instantly cooled in a
vacuum chamber
 Packed in pre-sterilized containers

8. difference between HTST and UHT
Pasteurization Techniques
Category HTST UHT
Temperature much lower temperature. (71.7 °C) comparatively higher
temperature. (140°C)
Duration HTST pasteurization takes much longer
duration with compared to UHT
pasteurization.
UHT pasteurization takes
only seconds.
Shelf-Life provides lower shelf life period (2-
3 weeks)
provides longer shelf life
period (2-3months)
Technique basically a pasteurization
technique
pasteurization technique as
well as a sterilization
technique.
Color and flavor preserves the color and flavor of
the food
does not preserve the color
and flavor
Protein
denaturation
does not cause protein
denaturation
causes structural damages
to the protein structure