1. Product (pH, water activity, viscosity, specific gravity) 2. Microbial profile (number, type, heat
resistance) 3. Equipment design 4. Package
TEMBRETURE
Product must be pumpable. 2. Flow rate of product must be controlled and verified. 3. Process time
and temperature must sterilize the product. 4. Product must be held at temperatures to achieve
sterilization. 5. Product must be cooled before the aseptic fill. 6. System must be pre-sterilized and
must maintain sterility throughout production. 7. System must be engineered to keep non-sterile
product from entering the filler.
LTHT
STHT
f 72°C for 15
HEAT KILL GERMS
AND BACTERIA(salmonila and listeria)
Bacillus licheniformis is the most common spore isolated in raw milk and Bacillus subtilis is the most
common spore isolated in sterilized milk. Poor quality raw milk contains gram negative organisms, which
can produce heat resistant enzymes
Bacilus can live in UHT milk ??!!
HESTORY
SAID EFFECT ON MILK
Refrigeration can extend product quality throughout shelf life. Temperature abuse throughout storage and
distribution can result in discoloration, separation, and gelation
OTHER PRODUCTS CAN BE A UHT (SUNQWICK)
SAME AMOUNT OF CL+ IN UHT AND PASTURIZATION
UHT processing reduces B vitamins by 10%, folic acid by 15%, and vitamin C by 25%. The nutritional value of
proteins, minerals, and fats are affected minimally by UHT processing
V B12 AND OTHER SAME IN BOTH
UHT processing reduces B vitamins by 10%, folic acid by 15%, and vitamin C by 25%. The nutritional value of
proteins, minerals, and fats are affected minimally by UHT processing
Some nutritional loss can occur in UHT milk
WHAT DO FACTORY NEED TO UHT PRODUCTS
WHY THIS TIME AND TEMPRATURE
Fennema's Food Chemistry, 2008
HOW DOSE WHY PROTIENS EFFECT BY OVER 80C*
used for other products such as fruit juices, cream, yogurt, wine, and soups
1.The sterile product, sterile package, and sterile zone prevent post-processing contamination. 2. The food
contact surfaces of the package are sterile. 3. Product is filled aseptically into the package. 4. Packages are
sealed hermetically. 5. Automation exists in monitoring and controlling the critical points.
Post Process Contamination Concerns
Type 1 failure results from raw ingredient, handling, storage, or batching issues. - Type 2 failure results
from processor and filler CIP, sanitation, preventive maintenance, and pre-sterilization issues. - Type 3
failure results from the thermal process heating cycle including regeneration. - Type 4 failure results from
the cooling cycle including surge tanks. - Type 5 failure results from sterilization issues with the package. -
Type 6 failure results from sterility loss in the aseptic zone or from environmental load. - Type 7 failure
results from loss of package integrity.
Raw Material Quality and Microbiology
1. milkfat (3.2 to 4.0%) 2. pH (6.40 to 6.80) 3. protein content (3.0 to 3.5%) 4. standard plate counts (<
100,000 cfu/g for single producers and <300,000 cfu/g for commingled loads) 5. titratable acidity (0.13 to
0.15%) 6. total solids (11.5 to 12.0%)
odor and milk change
A study conducted by Korel and Balaban (2002) suggested that odor changes in milk samples inoculated
with Pseudomonas fluorescens or Bacillus coagulans could be detected by an electronic nose
Chemical Changes
changes in milk depend on raw ingredient quality, the processor, and the scheduled process. Direct heat
processing imparts less adverse chemical changes
Physical Changes
The color of UHT milk products is affected by milk composition, homogenization pressure, heat
treatment, and storage conditions. Dairy foods with greater quantities of reducing sugars have more
issues with browning
Commercial Sterility Testing
The genera Bacillus and Clostridium are the primary sporeforming spoilage microbes