Academic literature on the topic 'PEF-technology'

Dairy and plant-based proteins are widely utilized in various food applications. Several techniques have been employed to improve the techno-functional properties of these proteins. Among them, pulsed electric field (PEF) technology has recently attracted considerable attention as a green technology to enhance the functional properties of food proteins. In this review, we briefly explain the fundamentals of PEF devices, their components, and pulse generation and discuss the impacts of PEF treatment on the structure of dairy and plant proteins. In addition, we cover the PEF-induced changes in the techno-functional properties of proteins (including solubility, gelling, emulsifying, and foaming properties). In this work, we also discuss the main challenges and the possible future trends of PEF applications in the food proteins industry. PEF treatments at high strengths could change the structure of proteins. The PEF treatment conditions markedly affect the treatment results with respect to proteins’ structure and techno-functional properties. Moreover, increasing the electric field strength could enhance the emulsifying properties of proteins and protein-polysaccharide complexes. However, more research and academia–industry collaboration are recommended to build highly effective PEF devices with controlled processing conditions.

The aim of this study was to evaluate the ability of pulsed electric field (PEF) technology to improve the extractability and enhance the oil quality in an industrial olive oil extraction process. Using a PEF device on olive pastes significantly increased the extractability from 79.5% for the control, up to 85.5%. The PEF system did not modify the primary legal quality parameters or total concentrations of phenols, aldehydes, and esters. On the contrary, the non-thermal treatment slightly enhanced the dialdehydic forms of decarboxymethyl elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and tyrosol (p-HPEA-EDA), and decreased the total saturated and unsaturated C5 and C6 alcohols of the PEF EVOO (Extra Virgin Olive Oil) compared to the control test. This study confirmed that PEF technology can improve olive oil extraction and quality.

Pulsed electric field (PEF) processing is an emerging non-thermal technology that shows potential to improve food quality and to maintain stability. Glutinous rice is composed mainly of amylopectin and has low amylose content. This study investigated the effect of PEF treatment at 3 kV/cm field strength for 50 to 300 pulses on whole, water-soaked glutinous rice grains. Micro-pores were created at the surface of PEF treated rice grains, increasing grain porosity from 7.3% to 9.8%. Peak viscosity of PEF treated rice flour decreased, and breakdown, final and setback viscosities increased as the number of PEF treating pulses increased, indicating that the swelling degree of rice starch was promoted after PEF treatment. Lower values of gelatinization enthalpy and lower crystalline degree of PEF treated glutinous rice flour were also observed. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) studies confirmed the secondary structure changes in rice protein and partial gelatinization of rice starch after PEF treatment.

The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular content and transfer of genetic material across cell membrane. The lethal effects of PEF to microorganisms were studied in 1990s when laboratory and pilot plant equipment were developed to evaluate the effect of PEF as a nonthermal food process to provide consumers with microbiologically-safe and fresh-like quality foods. Application of high voltage electric field at a certain level for a very short time by PEF not only inactivates pathogenic and spoilage microorganisms, but also results in the retention of flavor, aroma, nutrients, and color of foods. The first commercial PEF pasteurization of apple cider products took place in 2005 in the United States. This paper provides current information about PEF food processing and identifies a list of research needs to further develop PEF technology for food processing and preservation.

The aim of this work was to investigate the effect of pulsed electric fields (PEF) on the growth and acidification kinetics of Lactobacillus delbrueckii subsp. bulgaricus CFL1 during fermentation. The PEF treatments were applied during the fermentation process using a recirculation pump and a PEF treatment chamber coupled with a PEF generator. The medium flow rate through the chamber was first optimized to obtain the same growth and acidification kinetics than the control fermentation without medium recirculation. Different PEF intensities (60–428 V cm−1) were then applied to the culture medium to study the impact of PEF on the cells’ behavior. The growth and acidification kinetics were recorded during the fermentation and the specific growth rates µ, pH, and acidification rate (dpH/dt) were assessed. The results obtained showed a biphasic growth by applying high PEF intensities (beyond 285 V cm−1) with the presence of two maximal specific growth rates and a decrease in the acidification activities. It was demonstrated that the cells were stressed during the PEF treatment, but presented an accelerated growth after stopping it, leading thereby to similar absorbance and pH at the end of the fermentation. These results show the great potential of PEF technology to be applied to generate low acidified products by performing PEF-assisted fermentations.

A pulsed electric field (PEF) is a technology used for microbial inactivation in food and beverages. This study aimed to examine the effect of PEF treatment on microbial inactivation and quality parameters in Thai orange juice (TOJ). The results showed that PEF and conventional thermal pasteurization (CTP) can be performed for inactivation of Staphylococcus aureus and Escherichia coli in TOJ. A 5-log reduction was obtained after 10 pulses of PEF treatment when using and electrical field strength of 30 kV cm−1, and the microbial inactivation by the PEF treatment resulted from the electroporation more than the temperature. Moreover, PEF treatment affects the quality parameters less than CTP. Moreover, PEF treatment did not affect the TOJ quality parameters such as pH, commission international de l’eclairage (CIE), viscosity, and total soluble solid (TSS), but saved vitamin C and all sugar and all mineral (sucrose, glucose, fructose, sodium, lithium, potassium, magnesium, and calcium) values more than CTP treatment.

Olive leaves (OLL) are reported as a source of valuable antioxidants and as an agricultural by-product/waste. Thus, a twofold objective with multi-level cost and environmental benefits arises for a “green” standalone extraction technology. This study evaluates the OLL waste valorization through maximizing OLL extracts polyphenol concentration utilizing an emerging “green” non-thermal technology, Pulsed Electric Field (PEF). It also provides further insight into the PEF assistance span for static solid-liquid extraction of OLL by choosing and fine-tuning important PEF parameters such as the extraction chamber geometry, electric field strength, pulse duration, pulse period (and frequency), and extraction duration. The produced extracts were evaluated via comparison amongst them and against extracts obtained without the application of PEF. The Folin-Ciocalteu method, high-performance liquid chromatography, and differential scanning calorimetry were used to determine the extraction efficiency. The optimal PEF contribution on the total polyphenols extractability (38% increase with a 117% increase for specific metabolites) was presented for rectangular extraction chamber, 25% v/v ethanol:water solvent, pulse duration (tpulse) 2 μs, electric field strength (E) 0.85 kV cm−1, 100 μs period (Τ), and 15 min extraction duration (textraction), ascertaining a significant dependence of PEF assisting extraction performance to the parameters chosen.

Development and adoption of more efficient and robust technologies for reuse of wastewater embedded resources, in particular materials and energy, is becoming an unavoidable necessity. Among many emerging technologies in the sector of wastewater treatment residuals valorization, Pulsed Electric Field (PEF) processes have shown interesting potential, although they have not yet entered the sector’s mainstream as a consolidated commercial technology, as in other industrial applications, such as the food, medical, and bio-based industries. PEF is a non-thermal technology suitable to biological applications, involving gentle cell disintegration and enhanced cell membrane permeability and as such applicable to disinfection, sterilization, and to those processes that benefit from an enhanced extraction of organic compounds from biological matter, such as anaerobic digestion, biological processes for recovery of nutrients, and biorefinery of cell-embedded compounds. PEF technology applications in wastewater/biomass residues management are reported and advantages, drawbacks, and barriers of the technology are discussed in this paper.

In recent years, Pulsed Electric Field (PEF) technology has been developing in laboratories and is starting to be established in the industry, mainly in the agri-food sector. So far all experimentations on the use of PEF in the wine industry was carried out at the laboratory scale on some kilograms of grapes, or liters of wines. Since 2015, we are studying the interest of the use of PEF on grape polyphenols extraction on a semi-industrial scale of 2 tons per hour. The first tests were carried out by comparing the PEF technology to a control, and a conventional thermovinification with liquid phase vinification and traditional vinification with different fermentation times. The first results obtained are encouraging. Vinified in the liquid phase, the grapes treated with PEF give wines with a color intensity of 20 to 30% higher than the control and a higher TPI of 7 to 17%. In the liquid phase, the treatment of the harvest by PEF does not make it possible to obtain the extraction level of the thermovinification. After a short maceration of 3 days, the polyphenols extraction level is similar to the thermovinification, and greater after 14 days, and so is the color (respectively +12 and +16%). No change in IBMP content was observed. The wines resulting from treatment of the harvest by PEF do not have the aromatic profile of thermovinification wines. The PEF has a fruity character comparable to the control and accentuates the aromatic characteristics of the grape variety. The wine are often judged less aggressive and astringent by reinforcing the perception of sweetness and full bodied. A few tests in white grape harvest by PEF, shows a significant gain of the thiols and terpenols.

This study’s aim is to evaluate Pulsed Electric Fields (PEF) technology as an alternative method for the processing of red grape juice. For this purpose, two PEF treatments were applied: first to grapes for polyphenol enrichment of the juice, and subsequently for microbial decontamination of the obtained juice. Juice obtained from PEF-treated grapes (5 kV/cm, 63.4 kJ/kg) had the polyphenol content 1.5-fold higher and colour intensity two times higher of control juices by spectrophotometric measurement (p ≤ 0.05). A subsequent decontamination treatment by PEF (17.5 kV/cm and 173.6 kJ/kg) achieved inactivation of the present microbiota (yeasts, moulds, and vegetative mesophilic bacteria) below detection level (<30 CFU/mL). Furthermore, PEF-treated juices were microbiologically stable up to 45 days, even at abusive refrigeration storage temperatures (10 °C). PEF juice quality and sensory characteristics were similar to a fresh juice; they were neither affected by the PEF decontamination treatment, nor by storage time and temperature. Results obtained in this study demonstrate the considerable potential of PEF for the production of a polyphenol-enriched and microbially stabilized red grape juice as a unique and sustainable alternative for the juice industry, while avoiding enzymatic and heat treatments.

In questo studio è stato valutato l'impatto dei campi elettrici pulsati applicati a diverse intensità (0.3, 0.9 e 1.5 kV/cm) su campioni di branzino fresco prima del processo di salamoiatura. Dopo 24, 96, 144 e 92 ore sono stati determinati il peso, il contenuto in acqua, la percentuale di NaCl, l'attività dell'acqua e il contenuto in TBARS nei campioni allo scopo di verificare la possibilità di accelerare il trasferimento di massa nella matrice, e in secondo luogo per valutare l'effetto dei campi elettrici pulsati sull'ossidazione lipidica.

One of the main polluting industries in the world with high environmental impact is the construction industry which also generates a huge amount of waste. To overcome the seburdens, we need to reduce the impacts through new solutions, technologies and by injecting circular economy concept into the industry. Construction and building material industry are responsible for nearly 11% of all GHG emissions and the usage of residential/commercial buildings is contributing to 28% of all GHG emissions globally. the construction industry is also responsible for 35% of the total wastes in the European Union. Both linear economy and emissions of the construction sector are becoming more important in recent years that led to the development of many standards, frameworks and innovations. Reporting environmental burdens of the construction elements, products and construction works or construction projects is one of the ways for emissions accounting. Therefore, a report on environmental impacts of goods or services is called environmental product claims which can be based on a single criterion (like CO2 emission or % of recycled content) or based on a complete LCA study with multiple impacts. These reports have been classified by ISO 14020 series in three types, Type I (third-party certified label), Type II (self-declared claims) and Type III (the third party verified declaration based on LCA study). The third type is known as Environmental Product Declaration (EPD). To make the LCA results in EPD:s comparable, Product Category Rules (PCR) are developed. The regulations for the construction materials are defined in EN 15804 so the declarations of the building materials and construction works according to these regulations are compliant with EN 15804. Another framework for environmental declarations called, Product Environmental Footprint (PEF) is developed in Europe. Besides Business to Business declarations that are the target group for EN 15804, PEF also includes environmental labelling (type I) with consumers as the target group. The PCR:s from the updated version of EN15804:2012+A2:2019 can be regarded as the parallel methodology specification for the construction materials in the PEF system. Other product groups' rules and specifications are based on the PEF guidance document. The overall aims of this study are to compare the EN 15804 and PEF formulas concentrating on credits at the end of life and after the end of life stage and to reduce the subjectivity of two variables, energy margin, and recycling rate in the assessment of recycling alternatives after the end-of-life stage. Calculated credits can be included differently in the environmental declarations depending on the methodological approach. PEF includes the End-of-Life (EoL) credits into the Life Cycle Assessment (LCA) study and adds them to the product's performance results, while EN 15804 mandates to report the credits from recycling/recovery separately as supplementary information to the products environmental performance. To compare the credits that are calculated according to PEF and EN 15804, a separate indicator is virtually defined for PEF in order to calculate all the credits separately and compare the results with EN 15804 Module Dresults to give the reader an overview of the most beneficial uses of the construction waste according to PEF and EN 15804. Reducing subjectivity of choosing recycling rate has been addressed by developing more transparent and less subjective tool by integrating and using DGNB (German Sustainable Building Council) and BRE (center for building research in the UK) methods. For energy margin, this has been done by integrating energy margin calculation tool by CDM (Clean Development Mechanism, United Nations) and find the contribution of different materials to the environmental benefits in and after the end of life stage of the building lifecycle. However, the DGNB and BRE methods require further development, since they are not originally developed for LCA studies and just used as the only current options available in order to make recyclability assessment methods compatible with LCA studies. Other methods, specifically for LCA, can also be developed in the future. Based on an inventory of the components and materials used in a real building, the most environmental benefits (credits) from downstream recycling/recovery considering all materials are generated for the wooden products when using the EN 15804 formula, while aluminium is in the second place. On the other hand, aluminium is in the first place and wood is second using the PEF formula. Aluminium has by far the most benefits (credits) considering the credits per kg of each material, due to the huge recycling potential that aluminium has and will replace primary aluminium in the future. Unlike PEF, EN 15804 reports all credits separately outside of the LCA system boundary. This is very beneficial since the correct verified LCA will not beaffected by the credits that are given based on current technologies when the end of life of the building components are between 40 to 120 years away from today.
En av de industrier i världen med högst miljöpåverkan är byggbranschen som också genererar en enorm mängd avfall. För att hantera detta måste vi minska effekterna genom nya lösningar, teknologier och genom att använda konceptet cirkulär ekonomi i byggbranschen. Bygg- och byggnadsmaterialindustrin är ansvarig för nästan 11% av alla växthusgasutsläpp och användningen av bostäder / kommersiella byggnader bidrar till 28% av allaväxthusgasutsläpp globalt. Byggbranschen ansvarar också för 35% av det totala avfallet i EU. Både linjär ekonomi och utsläpp från byggsektorn har blivit viktigare under de senaste åren vilket har lett till utveckling av många standarder, ramverk och innovationer. Att rapportera miljöbelastningar för byggelement, produkter och bygg- och anläggningsarbeten är ett av sätten för utsläppsredovisning. Därför kallas en rapport om miljöpåverkan av varor eller tjänster Miljömärkning som kan baseras på ett enda kriterium (som CO2-utsläpp eller procent av återvunnet innehåll) eller baserat på en fullständig LCAstudie med flera effekter. Dessa rapporter har klassificerats enligt ISO 14020-serien i tre typer, typ I (tredjepartscertifierad märkning), typ II (självdeklarerade påståenden) och typ III (tredjepart verifierad deklaration baserad på LCA-studie). Den tredje typen är känd som Miljövarudeklaration/Environmental Product Declaration (EPD). För att göra LCA-resultat i EPD:er jämförbara, utvecklas Product Category Rules (PCR) (Produktkategoriregler). Regler för byggnadsmaterialen definieras i EN 15804, så deklarationerna om byggnadsmaterial och byggnadsarbeten enligt dessa regler överensstämmer med EN 15804. Ett annat ramverk för miljödeklaration är ProductEnvironmental Footprint (PEF) som är utvecklad inom EU. Förutom Business to Businessdeklarationer som är målgruppen för EN 15804 inkluderar PEF också miljömärkning (typ I) med konsumenter som målgrupp. PCR:erna från den uppdaterade versionen av EN 15804:2012 + A2: 2019 kan betraktas som den parallella metodspecifikationen för byggmaterialen i PEF-systemet. Andra produktgruppers regler och specifikationer är baserade på PEFs vägledningsdokument. De övergripande syftena med denna studie är att jämföra formlerna EN 15804 och PEF som koncentrerar sig på krediter i slutet av livscykeln och att minska subjektiviteten för två variabler, energimarginal och återvinningsgrad vid bedömningen av återvinningsalternativ i slutet av livscykeln. Beräknade krediter kan inkluderas olika i miljödeklarationerna beroende på den valda metoden. PEF inkluderar slutet av livscykeln (EoL)-krediter i livscykelanalys (LCA) -studien och lägger dem till produktens resultat, medan EN 15804 kräver att krediterna från återvinning rapporteras separat som kompletterande information till produkternas miljöprestanda. För att jämföra krediter som beräknas enligt PEF och EN 15804, definieras en virtuell separat indikator för PEF för att beräkna alla krediter separat och jämföra resultaten med EN 15804 Modul D-resultat för att ge läsaren en översikt över de mest fördelaktiga användning av byggavfall enligt PEF och EN 15804. Olika sätt att minska subjektiviteten i valet av återvinningsgrad behandlas genom att utveckla mer transparenta och mindre subjektiva verktyg med hjälp av metoder från DGNB (German Sustainable Building Council) och BRE (Center for building research, UK). Energimarginal behandlas genom att integrera ett verktyg för energimarginaler från CDM (Clean Development Mechanism, FN) och hitta bidraget från olika material till miljöfördelarna i och efter livscykeln för byggnaden. DGNB och BRE metoderna kräver emellertid ytterligare utveckling, eftersom de inte ursprungligen är utvecklade för LCA-studier och bara används som de enda tillgängliga alternativen för att göra utvärderingsmetoder för återvinningsbarhet kompatibla med LCA-studier. Andra metoder, speciellt för LCA, kan också utvecklas i framtiden. Baserat på en inventering av komponenter och material som används i en riktig byggnad, genereras de största miljömässiga fördelarna (krediter) av nedströms återvinning av träprodukter när man använder EN 15804-formeln, medan aluminium ligger på andra plats. Å andra sidan är kommer aluminium i första hand och trä kommer på andra plats med PEFformeln. Aluminium har överlägset flest fördelar (krediter) per kg av varje material, på grundav den enorma återvinningspotentialen som aluminium har och kommer att ersätta primärt aluminium i framtiden. Till skillnad från PEF rapporterar EN 15804 alla krediter separat utanför LCA-systemgränsen. Detta är mycket fördelaktigt eftersom den korrekta verifierade LCAn inte kommer att påverkas av de krediter som ges baserat på nuvarande teknik när byggnadskomponenternas livslängd är mellan 40 och 120 år från idag.

Pulsed Electric Fields (PEF) is a non-thermal technique that causes electroporation of cell membranes by applying very short pulses (μs) of a high-intensity electric field (kV/cm). Irreversible electroporation leads to the formation of permanent conductive channels in the cytoplasmic membrane of cells, resulting in the loss of cell viability. This effect is achieved with low energy requirements and minimal deterioration of quality. This chapter reviews the studies hitherto conducted to evaluate the potential of PEF as a technology for microbial decontamination in the winemaking process for reducing or replacing the use of SO2, for guaranteeing reproducible fermentations or for wine stabilization.

Dairy products include carbohydrates, protein, fatty acids, and different micronutrients, such as minerals and vitamins. Thermal treatment is generally used in dairy products to provide product safety and increase shelf life. But it can also lead to undesirable effects on dairy products such as protein denaturation, maillard reaction, and loss of vitamins. Non-thermal technology is an alternative method in the preservation of food products due to improving product safety and shelf life without any negative effects on food nutritional content. High hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound, cold plasma (CP), and pulsed light (PL) are the main non-thermal techniques that are used in the food industry. This chapter gives general principles of the non-thermal techniques, current applications in the dairy products, and recent advances in the dairy industry.

Dairy products include carbohydrates, protein, fatty acids, and different micronutrients, such as minerals and vitamins. Thermal treatment is generally used in dairy products to provide product safety and increase shelf life. But it can also lead to undesirable effects on dairy products such as protein denaturation, maillard reaction, and loss of vitamins. Non-thermal technology is an alternative method in the preservation of food products due to improving product safety and shelf life without any negative effects on food nutritional content. High hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound, cold plasma (CP), and pulsed light (PL) are the main non-thermal techniques that are used in the food industry. This chapter gives general principles of the non-thermal techniques, current applications in the dairy products, and recent advances in the dairy industry.

Consumers demand healthier fresh tasting foods without chemical preservatives. To address the need, food industry is exploring alternative preservation methods such as high pressure processing (HPP) and pulsed electric field processing. During HPP, the food material is subjected to elevated pressures (up to 900 MPa) with or without the addition of heat to achieve microbial inactivation with minimal damage to the food. One of the unique advantages of the technology is the ability to increase the temperature of the food samples instantaneously; this is attributed to the heat of compression, resulting from the rapid pressurization of the sample. Pulsed electric field (PEF) processing uses short bursts of electricity for microbial inactivation and causes minimal or no detrimental effect on food quality attributes. The process involves treating foods placed between electrodes by high voltage pulses in the order of 20–80 kV (usually for a couple of microseconds). PEF processing offers high quality fresh-like liquid foods with excellent flavor, nutritional value, and shelf life. Pressure in combination with other antimicrobial agents, including CO2, has been investigated for juice processing. Both HPP and PEF are quite effective in inactivating harmful pathogens and vegetative bacteria at ambient temperatures. Both HPP and PEF do not present any unique issues for food processors concerning regulatory matters or labeling. The requirements are similar to traditional thermal pasteurization such as development of a Hazard Analysis Critical Control Point (HACCP) plan for juices and beverages. Examples of high pressure, pasteurized, value added products commercially available in the United States include smoothies, fruit juices, guacamole, ready meal components, oysters, ham, poultry products, and salsa. PEF technology is not yet widely utilized for commercial processing of food products in the United States. The presentation will provide a brief overview of HPP and PEF technology fundamentals, equipment choices for food processors, process economics, and commercialization status in the food industry, with emphasis on juice processing. Paper published with permission.

Abstract Pulsed electric field (PEF) technology is a promising non-thermal pasteurization method that can be utilized to inactivate microorganisms in liquid food with high-voltage PEF. The power switch which is an important component of the PEF systems. This paper presents a design and implementation of an insulated gate bipolar transistor (IGBT) module which includes connections of three series and four parallel IGBTs and its special gate driver for small liquid food treatment systems at home. In this approach, two important issues must be considered. The first is to provide a safe operating condition for each single IGBTs in transient intervals. The second is to design gate drive systems with the capability of driving a large number of discrete devices simultaneously and ensure the current and voltage of single IGBTs in the module to be approximations. To evaluate the operation of the proposed structure, a module of three series and four parallel switches with the voltage capability of 1.8 kV and 60A is tested experimentally.

A two-phase flow heat transfer experiment platform using alternative refrigerant R134a as working fluid was designed and built to investigate the characteristics of two-phase flow heat transfer. It was primarily made up of circle power, heating/cooling sources, parallel test sections, accumulator and data acquisition system. The working loop was designed for performance pressure of 1.6 MPa and temperature of 200°C, preheated section power of 24 V × 300 A and test section of 60 V × 500 A. The refrigeration chilling unit had a maximum output of 50 kW. The preheated and test section were designed as horizontal helically-coiled tubes, and a visual reservoir made of electric melting-quartz glass was designed to observe flow patterns intuitively. Technology and methods related to fluid and mechanics were discussed in this paper including the aspects of materials and welding, sealing and heat preservation, special machining and accessories installation etc. Pressure testing, heat balance testing, heat transfer characteristics experiments were performed under various conditions to analyze the usability and stability of this platform. Test results showed that the leak ratio was no more than 250 Pa/h at 2.0 MPa and the heat loss of the system wrapped with PEF materials was less than 5%. Under the conditions of pressures of 0.30–0.95 MPa, mass fluxes of 120–620 kg/m2s, inlet qualities of −0.08–0.38 and heated power of 0.45–1.30 kW, R134a two-phase flow boiling heat transfer characteristics were investigated and discussed in detail. This platform can be used for studying the characteristics of two-phase flow pressure drop, boiling heat transfer and fluid-to-fluid modeling technique etc.