Ohmic heating as a promising technique for extraction of herbal essential oils: Understanding mechanisms, recent findings, and associated challenges

Gavahian, Mohsen; Sastry, Sudhir K.; Farhoosh, Reza; Farahnaky, Asgar

doi:10.1016/bs.afnr.2019.09.001

Cited by 40 publications

(14 citation statements)

References 114 publications

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“…Both the thermal and non‐thermal effects of ohmic treatment could contribute to the increased oleoresin extraction yield obtained in the present study. Gavahian et al (2020) pointed out that the main thermal effect of ohmic treatment in the extraction process is the release of the constituents of the tissue and cells due to biomass structure disruption by heat. Although this phenomenon seems to be analogous to that of the conventional heating extraction, the concept of internal heat generation when using ohmic heating can generate heat instantly everywhere inside the sample, leading to a more uniform and quicker heat distribution within the mixture compared to conventional heating that relies on heat convection and conduction mechanisms (Goullieux & Pain, 2014; Knirsch et al, 2010).…”

Section: Resultsmentioning

confidence: 99%

“…The permeability of the cell membrane is directly correlated with the mass transfer rate of substances between inside and outside of cells (Granot & Rubinsky, 2008) leading to the oleoresin extraction yield improvement. Gavahian et al (2020) claimed that the amplitude of non‐thermal effects on the extraction process depends on several parameters including the biomass characteristics and the conditions of the extraction process such as the electric field strength and temperature. Thus, the rapid heat generation inside the black pepper cell structure together with the electroporation effect were speculated to cause more ruptures in the ohmically heated sample.…”

Section: Resultsmentioning

confidence: 99%

“…The cell membrane of agricultural material has a specific dielectric strength, so whenever the electric field exceeds a certain level, electroporation occurs resulting in the breakdown of cell membranes (Knirsch et al, 2010). Electroporation is an aspect of ohmic heating that is interesting for extraction applications, since it might be able to raise the extraction efficiency compared to conventional heating (Gavahian et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Application of ohmic heating for black pepper ( Piper nigrum L.) oleoresin extraction compared with conventional heating

Chaminda

Jittanit

Lorjaroenphon

2022

Food Processing Preservation

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The aims of this research were to investigate the possibility of applying ohmic heating for assisting in solvent extraction of black pepper oleoresin and to compare the yield and quality of oleoresin with that obtained from the conventional heating method. The electrical conductivities were measured of black pepper powder mixed with different solvents and the residues from each extraction stage. The extraction was conducted in two stages using a black pepper powder‐to‐solvent ratio of 1:10. The electrical conductivities of the black pepper powder and residue mixtures ranged from 0.01 to 0.17 S/m depending on the ethanol‐to‐distilled water ratio and extraction stage. Ohmic heating extraction significantly improved the oleoresin yield and piperine content compared to conventional heating. The microstructures of the powder and residues obtained after extraction indicated that ohmic heating caused pores and fractures in the cell walls of black pepper cells that facilitated solvent and oleoresin transfer. Novelty impact statement This study revealed that the electrical conductivity is an indicator of the oleoresin content in the black pepper powder and raffinate. Moreover, ohmic heating has potential for the commercial extraction of black pepper oleoresin and provided scientific evidence of yield and quality improvement. The application of ohmic heating‐assisted extraction could broaden the technology for extracting spice oleoresins in the food industry.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of ohmic heating for black pepper ( Piper nigrum L.) oleoresin extraction compared with conventional heating

Chaminda

Jittanit

Lorjaroenphon

2022

Food Processing Preservation

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“…Ohmic heating, which employs joule heating, generates heat directly within the foodstuff by passing an electric current through it as an electrical conductor, raising the temperature of the food (Gavahian et al, 2020;Makroo et al, 2020). Many liquid food products and liquid-solid mixes can be cured quickly using Ohmic heating (Lee et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Electrical Conductivity Application in Ohmic Pasteurization of Orange Juice

Ahmed¹,

Sedeeq²,

Alhaji³

2022

MJA

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The conversion of electrical energy into heat energy, which results in internal energy generation, is the underlying premise of Ohmic heating. An experimental batch Ohmic heating unit was built and manufactured for this study. The effect of voltage gradient of alternating current during batch Ohmic heating on orange juice was investigated. Parameters such as temperature, electrical current, time consumption, system performance coefficient, and heating rate of orange juice under Ohmic heating process were studied. The time consumption such as (23.02, 11.25, and 2.19 minutes) to reach the Ohmic pasteurization temperature (95 °C) was decreased as the voltage gradients (9.20 V/cm, 12.64 V/cm, and 25.28 V/cm) increased respectively. The electrical current was rapidly increased (4.46 Amp.) in accordance with the higher voltage gradient (25.28 V/cm) to attain the pasteurization temperature. With rising voltage gradients, Ohmic heating resulted in greater system performance coefficient values. The heating rate appears to have grown dramatically as the voltage gradients increased.

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“…Some ohmic heating applications were done successfully including blanching (Allali et al, 2010), evaporation (Cokgezme et al, 2017), dehydration (Moreno et al, 2017), fermentation (Gavahian & Tiwari, 2020), extraction (Aamir & Jittanit, 2017; Saberian et al, 2017), sterilization (Choi et al, 2015; Mesías et al, 2016), pasteurization (Achir et al, 2016; Cho et al, 2017) and thawing (Icier et al, 2017; Liu et al, 2017). OAHD, combination of ohmic heating and hydrodistillation, is also an area researchers are interested in (Gavahian et al, 2020; Gavahian & Farahnaky, 2018; Hashemi et al, 2019; Taban et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Optimization of ohmic heating assisted hydrodistillation of cinnamon and bay leaf essential oil

Tunç

Koca

2020

J Food Process Engineering

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In this work, optimum ohmic heating assisted hydrodistillation (OAHD) conditions for extraction of cinnamon (CEO) and bay leaf (BEO) essential oil were determined by response surface methodology (RSM). OAHD were compared with conventional hydrodistillation (HD). Hydrodistillation time (30–120 min), mass of sample (20–40 g) and voltage gradient (7.5–12.5 V/cm), were varied to maximize essential oil (EO) yield and minimize energy consumption. Optimized OAHD conditions were determined as 119.90 min, 8.83 V/cm and 40 g, and 120 min, 8.53 V/cm and 40 g for CEO and BEO, respectively. EO yields of cinnamon and bay leaves at optimum conditions were found 3.98 ± 0.25% and 1.36 ± 0.14%, respectively. Energy consumptions were found 0.42 ± 0.02 and 0.86 ± 0.09 kWh/g EO for CEO and BEO, respectively. EO yield of OAHD was found to be higher when compared with HD methods for both plant materials. Energy consumptions and emitted CO2 values of OAHD method were significantly (p < 0.05) lower than HD methods. Cinnamaldehyde (CEO) and eucalyptol (BEO) contents of essential oils extracted with OAHD were higher when compared with HD methods. Antioxidant activities of essential oils extracted with different methods were not significantly different. CEO and BEO formed inhibition zones against all tested microorganism strains. Practical Applications Essential oils of cinnamon bark and bay leaf are commonly used for food and pharmaceutical industries and, have important economic value. Conventional hydrodistillation method to extraction essential oils is time consuming, requires more energy and has more CO2 emission rates. Ohmic heating assisted hydrodistillation as a novel technology, is a promising method to extraction of essential oils from different plant materials with lower process times and energy consumption when compared with conventional hydrodistillation. Ohmic heating assisted hydrodistillation method can developed with regard to scale up as a green technology to essential oil production. This work provides a knowledge about the effects of different OAHD process variables on essential oil yield and energy consumption for cinnamon bark and bay leaf essential oils. It is expected that the outcomes of this study will be useful for the designing of large scale ohmic heating assisted hydrodistillation units.

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Ohmic heating as a promising technique for extraction of herbal essential oils: Understanding mechanisms, recent findings, and associated challenges

Cited by 40 publications

References 114 publications

Application of ohmic heating for black pepper ( Piper nigrum L.) oleoresin extraction compared with conventional heating

Application of ohmic heating for black pepper ( Piper nigrum L.) oleoresin extraction compared with conventional heating

Electrical Conductivity Application in Ohmic Pasteurization of Orange Juice

Optimization of ohmic heating assisted hydrodistillation of cinnamon and bay leaf essential oil

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