1. Olive paste conditioning by an industrial continuous microwave system
University of Foggia - Italy
Department of the Science of Agriculture, Food and Environment
Olive paste conditioning by an industrial continuous microwave system
Dr. Roberto ROMANIELLO

2. The malaxer
University of Foggia, Department of the Science of Agriculture, Food and Environment

3. The malaxer Discontinuous machine Time-temperature profile:
variable on the basis of malaxer filling level;
not uniform for all olive pastes’ particles.
Discontinuous output than discontinuous feeding of the centrifugal extractor.
Big area required by malaxer machines.
High incidence of malaxation time on the total processing time
(> 50%).
Regulates the proper relationship between extraction yield and oil quality
It helps the destruction of cells and vacuoles
breaks the oil / water emulsion
reduces paste viscosity
chemical and biochemical reactions
University of Foggia, Department of the Science of Agriculture, Food and Environment

4. Aim of experiment
To evaluate the possibility to use a microwaves machine to heat the olive paste in an industrial olive oil mill
Frequency: 300 MHz GHz
Interaction with water molecules
University of Foggia, Department of the Science of Agriculture, Food and Environment

5. It break the oil/water emulsion and facilitate coalescence
Aim of experiment
MICROWAVES
Thermal effect
Non-thermal effect
The cavitation phenomenon leading to the implosion of the cell and vacuolar membranes
It break the oil/water emulsion and facilitate coalescence
University of Foggia, Department of the Science of Agriculture, Food and Environment

6. Experiment conduced in an industrial mill
Designing, dimensioning and developing of the continuous microwave system
Installing the continuous microwaves system in an industrial mill
Conducting experimental test
Evaluation of experimental results
University of Foggia, Department of the Science of Agriculture, Food and Environment

7. Continuous microwaves system
STALAM s.p.a. Nove (VI)
BREVETTO DI INVENZIONE INDUSTRIALE n del 9 aprile 2008, Metodo ed impianto per l’estrazione d’olio vegetale.
EMitech s.r.l. Corato (BA)
BREVETTO DI INVENZIONE INDUSTRIALE n
registrato il data 14/12/2012
Polyethilene pype: 65.4 mm Ø; length 4000 mm
4 magnetron x 6 kW (variable)
Frequency: 2.45 GHz
PLC controlled
Maximum mass flow rate: 3000 kg*h-1
ΔT=7,5 °C
University of Foggia, Department of the Science of Agriculture, Food and Environment

8. Modular unit of microwave machine
University of Foggia, Department of the Science of Agriculture, Food and Environment

9. Continuous microwaves system
1. Input; 2. PP tube; 3. Reverberant chamber; 4. Output; 5. Magnetron; 6. Power supply; 7. PLC; 8. Termocopule; 9. Water cooler; 10. Circulator.
DECANTER
CRUSHER
University of Foggia, Department of the Science of Agriculture, Food and Environment

10. Microwaves machine implementation in the industrial mill
University of Foggia, Department of the Science of Agriculture, Food and Environment

11. Experimental plan Acquired parameters:
Test
Cultivar
“T” MW
“T” Malaxer
Electrical power MW
“t” nalaxation
Mass flow rate M
Ogliarola G. -
28 °C
40 min
3000 kg*h-1
24 kW
17 sec
MW + M
20 min
Acquired parameters:
quantitative(Extraction efficiency)
qualitative (acidity, peroxide index, total polyphenols, volatile compounds)
Energy consumed by the two technologies used (MW; Malaxers)
University of Foggia, Department of the Science of Agriculture, Food and Environment

12. Quantitative results
Test
Oil content of pomaces
(% w.m.)
(% d.m.)
Extraction
efficiency (%) M
5.5 ± 0.2 a
12.5 ± 0.3 a
80.3 ± 0.5 a MW
5.6 ± 0.2 a
12.3 ± 0.3 a
80.9 ± 0.5 a
MW + M
12.1 ± 0.3 a
81.2 ± 0.4 a
University of Foggia, Department of the Science of Agriculture, Food and Environment

13. Qualitative results1/2
Test
Free acidity
(%)
Peroxide index
(meqO2 * kg-1)
Total phenols content
(mg * kg-1) M
0,57 ± 0,02 a
8,1 ± 0,4 a
407 ± 10 b MW
0,58 ± 0,03 a
6,9 ± 0,1 c
374 ± 9 c
MW + M
0,62 ± 0,06 a
7,3 ± 0,2 b
447 ± 14 a
Retention time
(min)
Phenols M MW
MW + M
6,6
p-HPEA
0,964 ± 0,040 b
0,154 ± 0,008 c
1,094 ± 0,017 a
36,8
3,4-DHPEA-EDA
6,160 ± 0,250 b
5,280 ± 0,010 c
7,480 ± 0,070 a
37,8
p-HPEA-EDA
2,430 ± 0,090 a
2,040 ± 0,050 b
2,500 ± 0,050 a
39,3
(+)-Pinoresinol
0,840 ± 0,019 b
0,959 ± 0,069 a
0,695 ± 0,008 c
42,8
3,4-DHPEA-EA
4,030 ± 0,250 b
3,820 ± 0,070 b
5,390 ± 0,140 a
45,2
p-HPEA-EA
0,680 ± 0,029 b
0,462 ± 0,015 c
0,995 ± 0,016 a
University of Foggia, Department of the Science of Agriculture, Food and Environment

14. Qualitative results 2/2 - Volatile compounds
MW + M M MW
University of Foggia, Department of the Science of Agriculture, Food and Environment

15. Evaluation of thermal energy consumed
36 kWh Thermal energy
Thermal energy (kWh)
Malxation time (min)
University of Foggia, Department of the Science of Agriculture, Food and Environment

16. Energy balance - mass flow rate = 3000 kg/h
Thermal energy = 36 kWh
Electrical energy = 12 kWh
Thermal energy = 0 kWh
Electrical energy = 38 kWh
University of Foggia, Department of the Science of Agriculture, Food and Environment

17. Conclusions Mechanical aspects Technological aspects
Simple implementation in an existing industrial plant
modularity
Easy adjustment of temperature and mass flow rate
Continuous conditioning of olive paste
Rapid and uniform heating of olive paste
Easy machine washing
Reduction of water volume for machine washing
Little installation space required
Thermal power plant not needed
Technological aspects
t-T profile uniform for all olive’s particles
Reduction of oil’s oxydation
Reduction of processing time
University of Foggia, Department of the Science of Agriculture, Food and Environment

18. References
University of Foggia, Department of the Science of Agriculture, Food and Environment

19. Thanks for your attention
University of Foggia - Italy
Department of the Science of Agriculture, Food and Environment
Thanks for your attention
Dr. Roberto ROMANIELLO