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The aim of this work was to investigate the effects of Ohmic heating-assisted hydrodistillation (OAHD), applied at different voltages (100, 150, and 200) V, on the qualitative and quantitative characteristics of extracted essential oil from oregano herb ( Origanum vulgare subsp. viride ), compared to a conventional hydrodistillation (HD) procedure. The compositions of the extracted essential oils (using OAHD and HD) were assessed using gas chromatography - mass spectrometry (GC–MS). A 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) method was applied in order to evaluate antioxidant activity. The antimicrobial activity as well as the minimum inhibitory concentration (MIC) values of the samples against Bacillus cereus, Escherichia coli O157:H7, Salmonella Typhimurium, Pseudomonas aeruginosa , and Staphylococcus aureus were determined. Among 50 identified compounds; thymol and 4-terpineol were the most abundant components independently of the technique used (OAHD or HD). No significant differences were observed between HD and OAHD (all voltages) methods in terms of extraction yields, and between HD and OAHD (at 100 V) in terms of antioxidant activity (the half inhibition concentration values (IC 50 ) were 33.4 μg/mL and 31.2 μg/mL, respectively). However, the extraction time was significantly reduced when OAHD extraction was used compared to HD. For the antimicrobial activity, the MIC values indicated higher inhibitory activities against S. aureus and B. cereus (with similar MIC values of 6.25 μg/mL) than P. aeruginosa (25 μg/mL). However, no significant influence was observed between the different applied voltages and the two extraction methods. OAHD could thus be used as “green” extraction method compared to HD. Industrial relevance The production of essential oils at industrial scale is mainly performed using conventional hydrodistillation method. However, the increasing need in applying more efficient and sustainable extraction processes has led researchers to evaluate new alternative non-conventional methods in order to replace the existing ones. Among non-conventional technologies applied to extract essential oils from plant materials, Ohmic-assisted hydrodistillation is of great potential. It allows reducing the extraction time compared to conventional hydrodistillation, which reduces significantly the energy consumption. The implementation of Ohmic-assisted hydrodistillation technology in essential oil producing industries is therefore of great importance.

The aim of this work was to evaluate the potential of the non-conventional pre-treatments; pulsed electric fields (PEFs) and ultrasounds (USNs), to enhance the extraction of red colorants from red prickly pear ( Opuntia stricta Haw.) peels and pulps. The overall goal was to valorize the thick part of the fruit, being discarded for fruit's consumption. PEF and USN treatments were first optimized using fruit slices, followed by a supplementary aqueous extraction (+ SAE) up to 1 h. The optimal conditions were then applied for peels and pulps, separately. Results showed that PEF + SAE and USN + SAE enhanced significantly the extraction of red colorants (betanin/isobetanin), compared to untreated tissues. Promising results for colorants recovery were obtained from fruit peels, using both pre-treatments, compared to that obtained from pulps, and without pre-treatment. Scanning electron microscopy revealed cell denaturation after PEF and USN pre-treatments, which can provide better recovery of the intracellular compounds with less impurity. Industrial relevance Wastes and by-products generated during fruit processing constitute a great source of high-added value compounds, which have the potential to be used as food additives and/or as nutraceuticals. Opuntia fruits constitute a great source of bioactive compounds. In particular, Opuntia fruit processing by-products are interesting as they contain a great amount of potential food additives, including food colorants (i.e. betanin/isobetanin), thus constituting an important alternative to replace synthetic colorants that have been restricted by governmental organizations. In this line, pulsed electric field and ultrasounds are proposed in this work as promising technologies for the enhancement of the extraction of colorants from red prickly pear peels and pulps.

Inulin constitutes an important food ingredient, widely used for its fiber content, and its ability to substitute fat and sugar ingredients. Traditionally, industrial inulin production from chicory roots requires high extraction temperature (70–80 °C) and long extraction time (1–2 h). This conventional extraction is generally accompanied with the presence of a large amount of impurities in the extracted juice, mainly due to the application of high temperature, requiring thus further purification steps. To overcome these issues, developing novel extraction technologies, consuming less energy, faster, and providing high yield and purity, is of paramount importance to meet the requirements of a green extraction concept. In this review, the feasibility of using conventional and new promising technologies (enzyme assisted extraction, ultrasounds, microwaves, supercritical fluid extraction, and pulsed electric fields) to recover inulin from plant food materials and by-products from an environmental and economical point of view will be discussed. Industrial relevance Inulin is widely used in food industries mainly due to its ability to substitute fat and sugar ingredients. However, the current industrial recovery process of this molecule is mainly carried out by diffusion in hot water (70–80 °C), followed by a relatively complex purification process, due to the presence of a large amount of impurities generated by the application of high temperatures. The need for obtaining greener, sustainable, and viable processes has led food scientists to develop new processes in full correspondence with the green extraction concept based on the use of non-conventional technologies (i.e. pulsed electric fields, ultrasounds, microwaves, etc). The submitted review discusses the potential of some of these new promising technologies to allow the industrial sustainability and green recovery of inulin, which have as benefits: energy- and time-saving along with higher yields and milder temperatures, reducing thus the subsequent purification steps.

The aim of this work was to investigate the potential of gas assisted mechanical expression (GAME) process as an innovative technology for oil extraction and polyphenol recovery from tiger nuts. GAME process was first studied by varying the supercritical carbon dioxide (SC-CO2) and the mechanical expression (ME) pressures (10–30 MPa), then was compared to separate processes applied alone, using either SC-CO2 or ME. The results showed that the better conditions for GAME were found using 20 MPa for SC-CO2 and 30 MPa for ME. Under these conditions, 50% of oil was released from tiger nuts after 10 min extraction, compared to only 10% and 20% when using SC-CO2 and ME separately at 20 and 30 MPa pressures, respectively. In addition to the faster extraction of oil using GAME process, the obtained results showed that this oil contains higher amount of polyphenols than that obtained using either SC-CO2 or ME. These molecules were extracted and identified using ultra performance liquid chromatography–high resolution mass spectrometry (UPLC–HRMS). Polyphenol profiles showed that GAME process led to the maximum polyphenol's recovery with 57 compounds, followed by SC-CO2 with 48 compounds, and ME process with only 27 compounds, concurring with the trends observed for total phenolic compounds. Although non-significant differences were observed in oil recovery after applying GAME or SC-CO2 alone, scanning electron microscopy (SEM) images revealed that GAME had a higher impact on cell structure, which can facilitate the release of important valuable compounds. All of these results pave the way towards the industrialization of GAME process as an innovative and alternative technology for enhanced oil extraction, thus replacing the conventional processes. Industrial relevance The increasing need in application of more efficient extraction processes in full correspondence with green extraction concept has led to deeper interest in new non-conventional methods that can reduce the extraction time, process temperature and consumption of toxic solvents (i.e. hexane). For instance, gas assisted mechanical expression (GAME) technology may constitute a useful tool for food industry as it allows to improve oil recovery and the amount of bioactive compounds (polyphenols) from tiger nuts, compared to supercritical fluid extraction and conventional methodologies (mechanical expression and hexane extraction) thus avoiding the use of toxic solvents.

The effect of moderate pulsed electric fields (PEF) on Hanseniaspora sp. fermentations in apple juice was examined. The treatments were applied prior to or during the fermentation using a field strength of 285 V/cm. A significant increase (p