This document summarizes a student's seminar on dense phase carbon dioxide (DPCD) technology. DPCD treatment involves pressurizing liquid foods with carbon dioxide to inactivate microorganisms without thermal effects. It describes the DPCD process, different treatment system types (batch, semi-continuous, continuous), mechanisms of microbial inactivation, advantages like freshness retention and environmental friendliness, disadvantages like cost, and applications in liquid and solid foods. The conclusion states that DPCD is a promising non-thermal pasteurization technology that can improve food quality and safety while avoiding thermal damage.

1. QUEENS COLLEGE OF FOOD TECHNOLOGY AND
RESEARCH FOUNDATION, AURANGABAD.
Student Name :- Aljilani Habib Mohammad
Reg. No :- 2016QCFT07B
Semester :- VI
Seminar Topic :- Dense Phase CO2 Technology
Seminar Guide :- Prof. Aziz Ansari

2. CONTENTS:
1. Introduction
2. What is DPCD Process?
3. Types of DPCD Treatment Systems
4. Mechanism of Microbial and Enzymatic Inactivation
5. Advantages
6. Disadvantages
7. Applications
8. Conclusion
9. Reference

3. INTRODUCTION:
 The need for a food preservation method is to make safe,
inexpensive foods with preservation of heat-sensitive
compounds.
 CO2 is used because of its safety, low cost, and high purity.
 Dense-phase carbon dioxide (DPCD) treatment is a non-
thermal treatment of liquid foods which inactivates micro-
organisms without the loss of nutrients or quality changes that
may occur due to thermal effects.
 It is also called as “cold pasteurization”

4. WHAT IS DPCD PROCESS:
 In this process, food is contacted with pressurized sub- or
supercritical CO2 for a period of time in a batch, semi-batch
or continuous manner.
 Pressure varies from 7 to 40 Mpa
 Temperature varies from 20 to 60 C
 Time taken during the batch processing 120 to 140 minutes,
and in semi and continuous it is 3 to 5 minutes

5. TYPES OF DPCD TREATMENT SYSTEMS:
3 Types of Treatment Systems Are Used:
 Batch type:- Both CO2 and treatment solution are stationary
in a container during treatment.
 Semi-continuous type:- continuous flow of CO2 through the
chamber while liquid food is stationary.
 Continuous type:- Flow of both CO2 and the liquid food.

6. BATCH TREATMENT SYSTEM:

7. CONTINUOUS TREATMENT SYSTEM :

8. MECHANISM OF MICROBIAL & ENZYMATIC
INACTIVATION:
Step 1 : Lowering of pH
Step 2 : Cell Membrane Modification
Step 3 : Intercellular pH Decrease
Step 4 : Enzyme Inactivation
Step 5 : Inhibition of Metabolism
Step 6 : Removal of Cell Constituents

9. ADVANTAGES:
 Gives fresh like food also after the treatment with minimum
energy consumption.
 Reduction of heat damage to food.
 Improve overall quality of food material.
 Waste free, environmental friendly and efficient technology.
 Low pressure and temperature is required as compared to
HPP.

10. DISADVANTAGES:
 False image of Co2
 Not possible at atmospheric pressure.
 Does not give complete inactivation of spoiled food.
 Low flow rate.
 High operation and capital cost.

11. APPLICATIONS IN LIQUID FOODS:

12. APPLICATIONS IN SOLID FOODS:

13. CONCLUSION:
 DPCD is a non-thermal technology that can inactivate certain
microorganisms and enzymes at temperatures low enough to
avoid the thermal effects of traditional pasteurization.
 DPCD treatment does not only improve food quality, but also
promote shelf life and (long-term) safety by inactivating
spoilage and pathogenic microorganisms.
 An emerging technology among all other technologies of
future generation.

14. REFERENCE:
 Arreola AG, Balaban MO, Marshall MR, Peplow AJ, Wei CI,
Cornell JA. 1991a. Supercritical CO2 effects on some quality
attributes of single strength orange juice. J Food Sci
56(4):1030–3.
 Chen JS, Balaban MO, Wei CI, Gleeson RA, Marshall MR.
1993. Effect of CO2 on the inactivation of Florida spiny
lobster polyphenol oxidase. J Sci Food Agric 61:253–9.
 Folkes G. 2004. Pasteurization of beer by a continuous dense-
phase CO2 Gainesville,Univ. of Florida, Aug 10, 2005.
 Fraser D. 1951. Bursting bacteria by release of gas pressure.
Nature 167:33–4.