Topic from Unit 3 - OBT554 - Principles of Food Preservation - Anna University R2017

1. OBT554
Unit 3

2.  There are two main temperature categories
employed in thermal processing:
Pasteurization and Sterilization
 Basic Purpose:
 to reduce or destroy microbial activity,
 reduce or destroy enzyme activity and
 to produce physical or chemical changes to make
the food meet a certain quality standard

3.  Mild processes: Blanching
 More severe processes: Canning, Baking,
Roasting, Frying

4.  Processes such as Pasteurisation and Sterilisation can
be done batchwise or continuously.
 Batch processing involves filling the vessel, heating,
holding, cooling, emptying the vessel, filling into
containers and cleaning the vessel.
 Holding times may be up to 30 min.
 Batch processes: easy to operate, flexible, able to deal
with different size batches and different products

8.  Foods can be heated and cooled more rapidly
compared to in-container processes.
 There are none of the pressure constraints which apply
to heating products in sealed containers. This allows
the use of higher temperatures and shorter times.
 Continuous processes provide scope for energy
savings, whereby the hot fluid is used to heat the
incoming fluid.

9. 1. Better protection of medium value
2. Ease of scale-up
3. Easier automatic control
4.The decrease of flow ability for steam
5.The reduction of sterilization cycle time
6. Under certain conditions, the decrease in
corrosion of fermentor

10. 1. Lesser assets apparatus expenditure
2. Less chance of contamination
3. Easier manual control
4. Easier to use with media having a high
amount of solid material

11. THANKYOU