Pulsed Electric Fields (PEF) as pre-treatment for freeze-drying of plant tissues

[EN] 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.Al-Sayed, L.; Boy, V.; Madieta, E.; Mehinagic, E.; Lanoisellé, J. (2018). Pulsed Electric Fields (PEF) as pre-treatment for freeze-drying of plant tissues. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1575-1582. https://doi.org/10.4995/IDS2018.2018.7484OCS1575158

Pulsed Electric Fields (PEF) as pre-treatment for freeze-drying of plant tissues

[EN] 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.Al-Sayed, L.; Boy, V.; Madieta, E.; Mehinagic, E.; Lanoisellé, J. (2018). Pulsed Electric Fields (PEF) as pre-treatment for freeze-drying of plant tissues. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1575-1582. https://doi.org/10.4995/IDS2018.2018.7484OCS1575158

Récents progrès en Génie frigorifique alimentaire : le point sur quelques communications marquantes du congrès ICR 2011 de Prague

International audienc

Extraction of oil from oleaginous/high-protein seeds, useful as animal fodder, comprises grinding and cold pressing of seeds to obtain fatty oil cake, washing the cake to recuperate residue, fractionating, and treating the residues

Extraction of oil from oleaginous or high-protein seeds (I) comprising:grinding and cold pressing of the seeds to obtain a fatty oil cake (II); washing (II) to recuperate a first solid residue (A);first fractionation of to separate a water with mucilage concentration and a second solid residue (B); second fractionation of to separate an emulsion concentrated in proteins and a third solid residue (C);and treatment of (C), is new. Extraction of oil from oleaginous or high-protein seeds (I) comprises: grinding and cold pressing of (I) to obtain a fatty oil cake (II); washing (II) to recuperate a first solid residue (A); fractionation of (A) to separate water with mucilage concentration and a second solid residue (B); fractionation of (B) to separate an emulsion concentrated in proteins and a third solid residue (C); and treatment of (C) (where the first and second fractionation comprises a treatment phase by high voltage electrical discharge).L'invention a pour objet un procédé d'extraction d'huile à partir de graines oléagineuses ou protéagineuses, comprenant une étape de broyage et une étape de pressage à froid à l'issue desquelles on obtient un tourteau gras, caractérisé en ce qu'il comprend :une étape de broyage suivie d'une étape de lavage dudit tourteau gras en vue de récupérer un premier résidu solide ;une première étape de fractionnement dudit premier résidu solide en vue de séparer une eau concentrée en mucilage et un deuxième résidu solide ;une deuxième étape de fractionnement dudit deuxième résidu solide en vue de séparer une émulsion concentrée en protéines et un troisième résidu solide ;une étape de traitement dudit troisième résidu solide en vue d'en extraire de l'huile,lesdites première et deuxième étapes de fractionnement incluant une phase de traitement par décharges électriques de haute tension

Conventional and Innovative Hygienization of Feedstock for Biogas Production: Resistance of Indicator Bacteria to Thermal Pasteurization, Pulsed Electric Field Treatment, and Anaerobic Digestion

International audienceAnimal by-products (ABP) can be valorized via anaerobic digestion (AD) for biogas energy generation. The digestate issued from AD process is usually used to fertilize farming land for agricultural activities, which may cause potential sanitary risk to the environment. The European Union (EU) requires that certain ABP be thermally pasteurized in order to minimize this sanitary risk. This process is called hygienization, which can be replaced by alternative nonthermal technologies like pulsed electric field (PEF). In the present study, Enterococcus faecalis ATCC 19433 and Escherichia coli ATCC 25922 were used as indicator bacteria. Their resistance to thermal pasteurization and PEF treatment were characterized. Results show that Ent. faecalis and E. coli are reduced by 5 log10 in less than 1 min during thermal pasteurization at 70 °C. The critical electric field strength was estimated at 18 kV∙cm−1 for Ent. faecalis and 1 kV∙cm−1 for E. coli. “G+” bacteria Ent. faecalis are generally more resistant than “G−” bacteria E. coli. AD process also plays an important role in pathogens inactivation, whose performance depends on the microorganisms considered, digestion temperature, residence time, and type of feedstock. Thermophilic digestion is usually more efficient in pathogens removal than mesophilic digestion

Mechanical Continuous Oil Expression from Oilseeds: A Review

International audienc

Overview of hygienization pretreatment for pasteurization and methane potential enhancement of biowaste: Challenges, state of the art and alternative technologies

International audienceHygienization reduces the public health risks involved in the application of biowaste to agricultural land. Recent advances in the hygienization of treated biowaste have not been reviewed to date. In many countries, the process involves using low temperature thermal pasteurization. Thermal hygienization accounts for between 6% and 25% of primary energy production in European biogas plants. Hygienization pretreatment can also influence the production of biogas by the treated substrates (from a slight negative effect to a biogas yield surplus of 50% in most cases). Alternative athermal pasteurization technologies (including electro-technology, microwave, pressurization, ultrasound and chemical treatment) have been shown to be capable of considerably reducing the number of bacteria and increasing the methane yield. The performance of these alternatives varies greatly and depends on the type of biowaste, the operational parameters studied, energy input and the method of interpreting the experimental results. Analyses of energy and exergy efficiency, of environmental impacts and of economic feasibility show that thermal hygienization may be the most energy efficient and economical approach when it exploits the wasted heat recovered from other processes. The present study also revealed that the research focus has been confined to the sewage sludge. Studies on the other biowaste, including animal by-products, are needed

Comparative study of ultrasound-assisted and conventional stirred dead-end microfiltration of grape pomace extracts

International audienc

Dead-End microfiltration behavior of disrupted yeast cell suspensions with stirring

FPS2010 - European Conference on Fluid-Particle Separation, Lyon, France, 5-7 October 2010, 157-158