The effect of pulsed electric fields pre-treatment on the volatile and phenolic profiles of Merlot grape musts at different winemaking stages and the sensory characteristics of the finished wines

The influence of pulsed electric fields (PEF) treatment on freeze-drying for potato and strawberry tissues was investigated. Samples were pre-treated by PEF ( 400 V cm-1) for different treatment times. Freeze-drying was carried out at -17°C and 18.4 Pa or 30 Pa for potato and strawberry tissues, respectively. The effects of PEF pre-treatment was compared with intact samples. The drying time was reduced by 35% for potato and 30% for strawberry. The sample rehydration capacity and the electrolytes released during the rehydration were higher for pre-treated samples. Strawberries texture was characterized by the hardness, the cohesiveness and the springiness.Keywords: Pulsed Electric fields; Freeze-drying; Potato; Strawberry; Textural Properties.

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Extraction of Antioxidant Compounds and Pigments from Spirulina (Arthrospira platensis) Assisted by Pulsed Electric Fields and the Binary Mixture of Organic Solvents and Water

Applied Sciences ◽

10.3390/app11167629 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7629

Author(s):

Francisco J. Martí-Quijal ◽

Francesc Ramon-Mascarell ◽

Noelia Pallarés ◽

Emilia Ferrer ◽

Houda Berrada ◽

...

Keyword(s):

Phenolic Compounds ◽

Binary Mixture ◽

Electric Fields ◽

Pulsed Electric Fields ◽

Extraction Yield ◽

Total Phenolic ◽

Antioxidant Compounds ◽

Total Phenolic Compounds ◽

Extraction Technology ◽

Pre Treatment

The application of pulsed electric fields (PEF) is an innovative extraction technology promoting cell membrane electroporation, thus allowing for an efficient recovery, from an energy point of view, of antioxidant compounds (chlorophylls, carotenoids, total phenolic compounds, etc.) from microalgae. Due to its selectivity and high extraction yield, the effects of PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction at different times (5–180 min) and with different solvents (ethanol (EtOH)/H2O, 50:50, v/v; dimethyl sulfoxide (DMSO)/H2O, 50:50, v/v) were evaluated in order to obtain the optimal conditions for the extraction of different antioxidant compounds and pigments. In addition, the results obtained were compared with those of a conventional treatment (without PEF pre-treatment but with constant shaking). After carrying out the different experiments, the best extraction conditions to recover the different compounds were obtained after applying PEF pre-treatment combined with the binary mixture EtOH/H2O, 50:50, v/v, for 60–120 min. PEF extraction was more efficient throughout the study, especially at short extraction times (5–15 min). In this sense, recovery of 55–60%, 85–90%, and 60–70% was obtained for chlorophylls, carotenoids, and total phenolic compounds, respectively, compared to the maximum total extracted amount. These results show that PEF improves the extraction yield of antioxidant bioactive compounds from microalgae and is a promising technology due to its profitability and environmental sustainability.

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Sludge pre-treatment with pulsed electric fields

Water Science & Technology ◽

10.2166/wst.2004.0625 ◽

2004 ◽

Vol 49 (10) ◽

pp. 123-129 ◽

Cited By ~ 25

Author(s):

O. Kopplow ◽

M. Barjenbruch ◽

V. Heinz

Keyword(s):

Electric Fields ◽

Anaerobic Degradation ◽

Energy Input ◽

Degradation Rate ◽

Pulsed Electric Fields ◽

Cell Content ◽

Specific Energy Input ◽

Sludge Treatment ◽

Pre Treatment ◽

Micro Organisms

The anaerobic stabilization process depends - among other things - on the bio-availability of organic carbon. Through pre-treatment of the sludge which leads to the destruction of micro-organisms and to the setting-free of cell content substances (disintegration), the carbon can be microbially converted better and faster. Moreover, effects on the digestion are likely. However, only little experience is available in sludge treatment with pulsed electric fields. Laboratory-scale digestion tests have been run to analyse the influence of pulsed electric fields on the properties of sludge, anaerobic degradation, sludge water reload and foaming of digesters. The results will be compared with those of other disintegration methods (high pressure homogeniser, thermal treatment). The effect of pre-treatment on the sludge is shown by the COD release. Degrees of disintegration have been achieved up to 20%. The specific energy input was high. The energy consumption has been decreased by initial improvements (pre-heating to 55¡C). The filament bacteria were partially destroyed. The foam reduction in the digesters was marginal. The anaerobic degradation performance has been improved in every case. The degradation rate of organic matter increased about 9%. Due to the increase of degradation, there is a higher reload of the sludge-water with COD and nitrogen compounds.

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Effect of pulsed electric fields pre-treatment on mass transport during the osmotic dehydration of organic kiwifruit

Innovative Food Science & Emerging Technologies ◽

10.1016/j.ifset.2016.10.011 ◽

2016 ◽

Vol 38 ◽

pp. 243-251 ◽

Cited By ~ 20

Author(s):

M.V. Traffano-Schiffo ◽

U. Tylewicz ◽

M. Castro-Giraldez ◽

P.J. Fito ◽

L. Ragni ◽

...

Keyword(s):

Mass Transport ◽

Electric Fields ◽

Osmotic Dehydration ◽

Pulsed Electric Fields ◽

Pre Treatment

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Pulsed electric fields (PEF) as hot air drying pre-treatment: Effect on quality and functional properties of saffron (Crocus sativus L.)

Innovative Food Science & Emerging Technologies ◽

10.1016/j.ifset.2020.102592 ◽

2021 ◽

Vol 67 ◽

pp. 102592

Author(s):

Lilia Neri ◽

Marianna Giancaterino ◽

Rachele Rocchi ◽

Urszula Tylewicz ◽

Luca Valbonetti ◽

...

Keyword(s):

Electric Fields ◽

Functional Properties ◽

Treatment Effect ◽

Pulsed Electric Fields ◽

Crocus Sativus ◽

Hot Air Drying ◽

Air Drying ◽

Hot Air ◽

Pre Treatment ◽

Crocus Sativus L

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Evolution of Volatile and Phenolic Compounds during Bottle Storage of Merlot Wines Vinified Using Pulsed Electric Fields-Treated Grapes

Foods ◽

10.3390/foods9040443 ◽

2020 ◽

Vol 9 (4) ◽

pp. 443 ◽

Cited By ~ 1

Author(s):

Mylene Ross Arcena ◽

Sze Ying Leong ◽

Martin Hochberg ◽

Martin Sack ◽

Georg Mueller ◽

...

Keyword(s):

Electric Fields ◽

Storage Temperature ◽

Temperature Stability ◽

Pulsed Electric Fields ◽

Prolonged Storage ◽

Processing Conditions ◽

Storage Study ◽

Energy Inputs ◽

Study Results ◽

Pre Treatment

This study aimed to elucidate changes in volatile, phenolic, and oenological profiles of wines vinified from Pulsed Electric Fields (PEF)-treated and untreated Merlot grapes during bottle storage of up to 150, 90, and 56 days at 4 °C, 25 °C, and 45 °C, respectively, through chemometrics technique. Wines produced from untreated grapes and those PEF-treated at four different processing conditions (electric field strength 33.1 and 41.5 kV/cm and energy inputs between 16.5 and 49.4 kJ/kg) were used for the bottle storage study. Results showed that hydroxycinnamic and hydroxybenzoic acids in all stored wines, regardless vinified from untreated and PEF-treated grapes, increased as a function of time and temperature, while anthocyanins and selected esters (e.g., ethyl butanoate) decreased. Extreme storage temperature, at 45 °C particularly, resulted in a higher amount of linalool-3, 7-oxide in all stored wines. After prolonged storage, all wines produced from grapes PEF-treated with four different processing conditions were shown to favor high retention of phenolics after storage but induced faster reduction of anthocyanins when compared to wines produced from untreated grapes. Moreover, some volatiles in wines vinified using PEF-treated grapes, such as citronellol and 2-phenylethyl acetate, were found to be less susceptible towards degradation during prolonged storage. Production of furans was generally lower in most stored wines, particularly those produced from PEF-treated grapes at higher energy inputs (>47 kJ/kg). Overall, PEF pre-treatment on grapes may improve storage and temperature stability of the obtained wines.

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Modelling of Carotenoids Content in Red Clover Sprouts Using Light of Different Wavelength and Pulsed Electric Field

Applied Sciences ◽

10.3390/app10124143 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4143

Author(s):

Ilona Gałązka-Czarnecka ◽

Ewa Korzeniewska ◽

Andrzej Czarnecki ◽

Paweł Kiełbasa ◽

Tomasz Dróżdż

Keyword(s):

Electric Field ◽

Blue Light ◽

Electric Fields ◽

White Light ◽

Light Exposure ◽

Red Clover ◽

Pulsed Electric Fields ◽

Pulsed Electric Field ◽

Pre Treatment ◽

Β Carotene

The paper presents the results of influence the light of different wavelengths and pulsed electric fields on the content of carotenoids. Seeds germination was carried out in a climatic chamber with phytotron system. The experiment was carried out under seven growing conditions differing in light-emitting diode (LED) wavelengths and using pulsed electric fields (PEFs) with different strength applied before sowing. Cultivation of the sprouts was carried out for seven days at relative humidity 80% and 20 ± 1 °C. Different light wavelengths were used during cultivation: white light (380–780 nm), UVA (340 nm), blue (440 nm), and red (630 nm). In addition, the pulsed electric field (PEF) with three values of strength equal to 1, 2.5 and 5 kV/cm, respectively, was applied to three series of sprouts before sowing. Sprouts treated with the PEF were grown under white light (380–780 nm). The light exposure time for all experimental series of sprouts was 12/12 h (12 h light, 12 h dark for seven days). Lutein is the dominant carotenoid in germinating red clover seeds, the content of which varies from 743 mg/kg in sprouts grown in red light, 862 mg/kg in sprouts grown in UVA, to 888 mg/kg in sprouts grown in blue light. Blue light in the cultivation of red clover sprouts had the most beneficial effect on the increase of carotenoids content and amounted to 42% in β-carotene, 19% in lutein, and 14% in zeaxanthin. It confirms that modelling the content of carotenoids is possible using UVA and blue light (440 nm) during seed cultivation. An increase in the content of β-carotene and lutein in red clover sprouts was obtained in comparison to the test with white light without PEF pre-treatment, respectively by 8.5% and 6%. At the same time a 3.3% decrease in the content of zeaxanthin was observed. Therefore, it can be concluded that PEF pre-treatment may increase mainly the content of β-carotene.

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