APPLICATIONS OF RADIOFREQUENCY TREATMENT FOR FOOD SAFETY AND PRESERVATION
Georgiana-Aurora ŞTEFÃNOIU*, Elisabeta Elena TÃNASE*, Paul Alexandru POPESCU*, Amalia Carmen MITELUŢ*, Mona Elena POPA*, Radu CRAMARIUC**, Ana Maria BALAUREA- CHIRILOV***, Gabriela
MOHAN****
*University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 MărăştiBlvd, District 1, 011464, Bucharest, Romania**Competence Center of Electrostatic and Electrotechnologies***S.C. Vel Pitar S.A.****Institute of Food Bioresources Bucharest (INCDBA-IBA)
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
TABLE OF CONTENTS
1.INTRODUCTION
2.MECHANISM OF RF HEATING
3.INACTIVATION MECHANISM OF MICROORGANISMS BY
RF
4.APPLICATIONS OF RADIOFREQUENCY TREATMENT IN
FOOD INDUSTRY
5.CONCLUSIONS
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
OBJECTIVE
This paper presents further the mechanism of action and the
applications of radiofrequency treatment with special emphasis on
the effect on the microorganisms involved in food spoilage.
INTRODUCTION
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
Research in novel heating of foods, for applications such as cooking,
pasteurisation/sterilisation, defrosting, thawing and drying, often focuses on
areas such as the assessment of processing time, the evaluation of heating
uniformity, the appraisal of the impact on quality attributes of the final product
as well as the prediction of the energy efficiency of these heating processes.
Research on electroheating accounts for a considerable portion of both the
scientific literature and commercial novel heating applications (Marra et al.,
2008).
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
INTRODUCTION
RF
13.56 MHz (+/- 0.05%)
27.12 MHz (+/- 0.06%)
40.68 MHz (+/- 0.05%)
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
INTRODUCTION
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
Radiofrequency
heating
offers alternatives to produce safe and wholesome foods
uses electromagnetic energy of a longer wavelength than
microwaves (MWs), which is of greater industrial
interest.
targets the product, not the air surrounding it.
many applications using RF heating as supplemental heat
have been developed successfully in the food-drying
industry for pasta, crackers, and snacks
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
MECHANISM OF RF HEATING
A schematic sketch of
the 2-kW, 27.12 MHz
radio frequency unit
(Awuah, 2005)
Radio frequency heating is
accomplished through a combination of
dipole heating and electric resistance
heating resulting from the movement of
dissolved ions present in the food.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
For RF heating, penetration depth is generally greater than 1 m, and can be
determined from a relationship that embodies the dielectric constant, the
loss factor, the speed of wave propagation in vacuum and, operating
frequency (Awuah et al., 2005).
Temperature, frequency, concentration and their interactions had different
levels of significance on the dielectric properties of starch solutions
(Piyasena et al., 2003).
MECHANISM OF RF HEATING
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
ELECTROPORATION
When a cell is exposed to an external electric field, charge is accumulated on the
cell membrane resulting in an artificial increase of the transmembrane potential
(TMP).
If such TMP increase is large enough, and sustained for long enough, cell
membrane permeability to ions and macromolecules will increase very
significantly. The increase in permeability is, presumably, related to the
formation of nano-scale defects or pores in the cell membrane; from which the
term electro- “poration” stems. If the induced permeabilization is moderate, cell
membranes will reseal and the cell will be fully viable in few minutes after field
delivery.
On the other hand, if the permeabilization is made excessive by delivering very
high or prolonged fields, cells will end up dying.
INACTIVATION MECHANISM OF
MICROOGANISMS BY RF
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
INACTIVATION MECHANISM OF
MICROORGANISMS BY RF
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
RADIOFREQUENCY
TREATMENT
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
Microbial and pest reduction by dielectric heating has been studied in many
experiments, including meat and meat products; poultry; eggs and egg
products; fish and shellfish; fruit and vegetable products such as canned fruit,
fruit juice, and jam; soy milk; sugar beet molasses; pea protein concentrates;
ready-cooked meals; milk and its products; puddings; cereals; breads; cakes;
pasta; starch; and spices (Mitelut and colab., 2011; Orsat and Raghavan,
2014).
Exposure of liposomes to frequencies of 27 and 100 MHz resulted in
increased lysis of vesicles (Trujillo and Geveke, 2014).
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
Radio frequency dielectric heating is now widely used in industrial
applications such as drying textile products (spools, rovings, and skeins), final
drying of paper, final dehydration of biscuits at outlets of baking ovens, and
melting honey.
Bottled juices including peach, quince and orange moving through an RF
applicator offered better bacteriological and organoleptic qualities than juices
treated by conventional thermal processing methods (Wang et al., 2003) .
RF heating can be applied to control pathogens in peanut butter products
without affecting quality (Guo et al., 2006).
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
RF heating for 50 s resulted in 2.80 to 4.29 log CFU/g reductions of S.
typhimurium and E. coli O157:H7 in black peppers and RF heating of red
peppers for 40 s reduced pathogens by 3.38 log CFU/g to more than 5 log
CFU/g (below the detection limit) without affecting the color quality change
(Kim et al., 2011).
Tofu was produced experimentally using RF-FH processed soybean milk
and conventionally heated soybean milk. Comparative studies revealed that
the tofu made by RF-FH processing had higher gel strength than the tofu
made by conventional heating (Uemura et al., 2010) .
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
Radio-frequency heating, coupled with appropriate packaging, can improve
the storability of repacked hams by reducing the bacterial load, reducing
moisture loss and maintaining an overall greater product sensory quality
and acceptance (Orsat et al., 2004).
RF treatment was also investigated in naturally infected fruit where the
Monilinia spp. development was completely inhibited in both ‘Summer
Rich’ and ‘Placido’ peaches. No brown rot control was observed in
nectarine fruit artificially inoculated or with natural inoculum (Casals et al.,
2010).
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
The non-thermal process of radio frequency electric fields (RFEF) has been
shown to inactivate bacteria in apple juice at moderately low temperatures,
but has yet to be extended to inactivate bacteria in orange juice. No loss in
ascorbic acid or enzymatic browning was observed due to RFEF processing
(Geveke et al., 2007).
Heating bread to 58°C or higher resulted in 4-log reduction of P. citrinum
spores isolated from moldy bread. The storage life at room temperature
(23°C) was extended by 28 ± 2 days for the treated white bread (Liu et al,.
2010).
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
It was determined the number of germs accoring to the standard SR ISO
4833-94.
It has been observed a
decrease of CFU with 2-3
log, which is directly
proportional with the increase
of temperature during the RF
treatment.
Grafic representation of CFU values
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
1 day after the RF treatment
2 days after the RF treatment
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
APPLICATIONS OF RADIOFREQUENCY TREATMENT
IN FOOD INDUSTRY
7 days after the RF treatment
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
The advantages of RF compared to another volumetric technologies are:
there is no need for electrodes contacting the food (in contrast with ohmic
heating), the RF treatment can be easily applied to both solid and liquid foods;
due to the longer wavelength of RF, its power will penetrate more deeply in the
foods as compared to microwave power;
the construction of large RF heating systems is simpler than their microwave
counterparts, and their application to continuous processes is straightforward;
it is a technology particularly suited to large industrial applications.
CONCLUSIONS
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
CONCLUSIONS
The reality today is that these novel processing technologies are being
tested for use in the food industry to improve the foods we eat, as they are
capable of inactivating microorganisms, changing cell permeability,
promoting chemical reactions, and even inactivating enzymes.
In fact, RF heating has been successfully applied in the food industry for
drying, baking and thawing, but controversial data are present on the effect
of RF on biological systems
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
Awuah G.B., Ramaswamy H.S., Economides A., Mallikarjunan K., (2005). Inactivation of Escherichia coli K-12 and
Listeria innocua in milk using radio frequency (RF) heating. Innovative Food Science and Emerging Technologies,
6, 396 – 402.
Casals C., Viñas I., Landl A., Picouet P., Torresa R., Usalla J., (2010). Application of radio frequency heating to control
brown rot on peaches and nectarines. Postharvest Biology and Technology, 58, 218–224.
Geveke D. J., Kozempela M., Scullena O. J., Brunkhorst C., (2002). Radio frequency energy effects on
microorganisms in foods. Innovative Food Science and Emerging Technologies, 3 (2), 133–138.
Liu Y., Tang J., Mao Z., Mah J.H., Jiao S., Wang S., (2010). Quality and mold control of enriched white bread by
combined radio frequency and hot air treatment. Journal of Food Engineering, 104, 492–498.
Marra F., Zhang L., Lyng J.G., 2008. Radio frequency treatment of foods: Review of recent advances. Journal of Food
Engineering 91, 497–508.
Mitelut A., Popa M., Geicu M., Niculita P., Vatuiu D., Vatuiu I., Gilea B., Balint R., Cramariuc R., (2011). Ohmic
treatment for microbial inhibition in meat and meat products. Romanian Biotechnological Letters, 16 (1), 149-152.
Orsat V., Raghavan G.S.V., (2014). Radio-Frequency Processing. Emerging Technologies for Food Processing (Second
Edition), 385–398.
Trujillo F. J., Geveke D. J., (2014). Nonthermal Processing By Radio Frequency Electric Fields. Emerging
Technologies for Food Processing (Second Edition), 259–269.
Uemura K., Takahashi C., Kobayashi I., (2010). Inactivation of Bacillus subtilis spores in soybean milk by radio-
frequency flash heating. Journal of Food Engineering, 100, 622–626.
SELECTIVE REFERENCES
This paper was realised under the frame of Partnerships in priority areas Programme, PCCA Contract no. 164 / 2014, RAFSIG.
WE: Bioeconomie: producție, procesare și consum sustenabile
26-28 aprilie 2016, Timisoara
THANK YOU FOR ATENTION!