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

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

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

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 - 300 GHz Interaction with water molecules University of Foggia, Department of the Science of Agriculture, Food and Environment

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

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

Continuous microwaves system STALAM s.p.a. Nove (VI) BREVETTO DI INVENZIONE INDUSTRIALE n. 0001390391 del 9 aprile 2008, Metodo ed impianto per l’estrazione d’olio vegetale. EMitech s.r.l. Corato (BA) BREVETTO DI INVENZIONE INDUSTRIALE n. 1396571 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

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

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

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

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

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

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

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

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

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

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

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

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