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27 results on '"Khelfa, Anissa"'

1. Isolation and Structural Characterization of Natural Deep Eutectic Solvent Lignin from Brewer's Spent Grains.

Author

Antoun, Karina, Tabib, Malak, Salameh, Sarah Joe, Koubaa, Mohamed, Ziegler-Devin, Isabelle, Brosse, Nicolas, and Khelfa, Anissa

Subjects
BREWER'S spent grain, LIGNOCELLULOSE, NUCLEAR magnetic resonance, QUANTUM coherence, INDUSTRIAL capacity, BIOPOLYMERS
Abstract

Brewer's spent grains (BSG) offer valuable opportunities for valorization beyond its conventional use as animal feed. Among its components, lignin—a natural polymer with inherent antioxidant properties—holds significant industrial potential. This work investigates the use of microwave-assisted extraction combined with acidic natural deep eutectic solvents (NaDESs) for efficient lignin recovery, evaluating three different NaDES formulations. The results indicate that choline chloride–lactic acid (ChCl-LA), a NaDES with superior thermal stability as confirmed via thermogravimetric analysis (TGA), is an ideal solvent for lignin extraction at 150 °C and 15 min, achieving a balance of high yield and quality. ChCl-LA also demonstrated good solubility and cell disruption capabilities, while microwaves significantly reduced processing time and severity. Under optimal conditions, i.e., 150 °C, 15 min, in the presence of ChCl-LA NaDES, the extracted lignin achieved a purity of up to 79% and demonstrated an IC50 (inhibitory concentration 50%) of approximately 0.022 mg/L, indicating a relatively strong antioxidant activity. Fourier transform infrared (FTIR) and 2D-HSQC NMR (heteronuclear single quantum coherence nuclear magnetic resonance) spectroscopy confirmed the successful isolation and preservation of its structural integrity. This study highlights the potential of BSG as a valuable lignocellulosic resource and underscores the effectiveness of acidic NaDESs combined with microwave extraction for lignin recovery. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Advancements in Non-Thermal Processing Technologies for Enhancing Safety and Quality of Infant and Baby Food Products: A Review.

Author

Pasdar, Nasim, Mostashari, Parisa, Greiner, Ralf, Khelfa, Anissa, Rashidinejad, Ali, Eshpari, Hadi, Vale, Jim M., Gharibzahedi, Seyed Mohammad Taghi, and Roohinejad, Shahin

Subjects
FOOD safety, ESSENTIAL nutrients, INFANT formulas, FUNCTIONAL foods, FOOD industry, BABY foods, BREAST milk
Abstract

Breast milk is the main source of nutrition during early life, but both infant formulas (Ifs; up to 12 months) and baby foods (BFs; up to 3 years) are also important for providing essential nutrients. The infant food industry rigorously controls for potential physical, biological, and chemical hazards. Although thermal treatments are commonly used to ensure food safety in IFs and BFs, they can negatively affect sensory qualities, reduce thermosensitive nutrients, and lead to chemical contaminant formation. To address these challenges, non-thermal processing technologies such as high-pressure processing, pulsed electric fields, radio frequency, and ultrasound offer efficient pathogen destruction similar to traditional thermal methods, while reducing the production of key process-induced toxicants such as furan and 5-hydroxymethyl-2-furfural (HMF). These alternative thermal processes aim to overcome the drawbacks of traditional methods while retaining their advantages. This review paper highlights the growing global demand for healthy, sustainable foods, driving food manufacturers to adopt innovative and efficient processing techniques for both IFs and BFs. Based on various studies reviewed for this work, the application of these novel technologies appears to reduce thermal processing intensity, resulting in products with enhanced sensory properties, comparable shelf life, and improved visual appeal compared to conventionally processed products. [ABSTRACT FROM AUTHOR]

Published
2024
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4. List of contributors

Author

Altuğ, Cevher, primary, Caggiano, Gianvito, additional, Castro-Muñoz, Roberto, additional, Ciotta, Simone Rocha, additional, Cosola, Carmela, additional, Costa, Silvio Cláudio, additional, Czinkóczky, Réka, additional, Dacome, Antonio Sérgio, additional, Díaz-Montes, Elsa, additional, Formigoni, Maysa, additional, García-Depraect, Octavio, additional, Gesualdo, Loreto, additional, Hajihashemi, Shokoofeh, additional, Karp, Sabina, additional, Khelfa, Anissa, additional, Koubaa, Mohamed, additional, Kurek, Marcin Andrzej, additional, Milani, Paula Gimenez, additional, Modi, Arpan, additional, Morlock, Gertrud, additional, Németh, Áron, additional, Palieri, Rita, additional, Raspe, Djéssica Tatiane, additional, Wasik, Andrzej, additional, Yücesan, Buhara, additional, Zimmermann, Benno F., additional, and Zorzenon, Maria Rosa Trentin, additional

Published
2021
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7. Strategies for increasing lipid accumulation and recovery from Y. lipolytica: A review☆

Author

El Kantar Sally, Khelfa Anissa, Vorobiev Eugène, and Koubaa Mohamed

Subjects
y. lipolytica, microbial oils, lipid accumulation, lipid extraction, biodiesel, Oils, fats, and waxes, TP670-699
Abstract

Microbial-based biodiesel is produced by transesterification of lipids extracted from microbial cells, and is considered as a potential replacement of fossil fuel due to its advantages in reducing greenhouse gas emissions. Yarrowia lipolytica is one of the most studied oleaginous yeasts able to produce lipids under some fermentation conditions and is considered as a potential industrial host for biodiesel production. Several approaches have been evaluated to increase the economical attraction of biodiesel production from Y. lipolytica lipids. In this review, we highlighted the different strategies reported in the literature, allowing this yeast to achieve high lipid accumulation. These include metabolic engineering strategies, the use of low-cost effective substrates, and the optimization of the cultivation conditions for higher lipid productivity and less operating cost. We also summarized the most effective cell disruption technologies that improve the extraction efficiencies of lipids from Y. lipolytica.

Published
2021
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21. Bioavailability of glucosinolates and their breakdown products:impact of processing

Author

Barba Orellana, Francisco Jose, Nikmaram, Nooshin, Roohinejad, Shahin, Khelfa, Anissa, Zhu, Zhenzhou, Koubaa, Mohamed, Barba Orellana, Francisco Jose, Nikmaram, Nooshin, Roohinejad, Shahin, Khelfa, Anissa, Zhu, Zhenzhou, and Koubaa, Mohamed

Abstract

Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability.

Published
2016

23. Etude des étapes primaires de la dégradation thermique de la biomasse lignocellulosique

Author

Khelfa, Anissa and UL, Thèses

Subjects
Mécanismes primaires, [CHIM.OTHE] Chemical Sciences/Other, Biomasse, Pyrolyse, Py-SM, ATG
Abstract

Biomass is a renewable energy source, which collect and stock CO2. The objectives of this work were to study the thermal behavior of natural biomass and its components (cellulose, hemicellulose and lignin). We were particularly interested in the thermal degradation mechanisms of natural polymers arising, first, during heat treatments (primary mechanisms). This work was carried out with in the framework of the ACI "Biomasters" with the support of Credit Mutuel. The thermal behaviors of biomass and its components were studied by using thermogravimetry (TGA), pyrolysis coupled with mass spectrometry(Py-MS) and pyrolysis coupled with gas chromatography with detection by mass spectrometry (Py-GC/MS). The thermal behaviors of biomass components were shown, by TGA, to be appreciably different and their roles were specified in thermal degradation. We also showed the impossibility of proposing estimated laws of biomass thermalbehavior on the basis of the main component TGA results. With Py-MS, we developed a method allowing to highlight the most representative molecular fragments evolved during biomass thermal degradation. This enabled us to specify the most sensitive components towards metallic catalystaction. The Py-CG/SM analysis of the mixtures showed that vapor compositions in the mixtures are close to simple laws of addition. We complete our work by an application of pyrolysis/gasification of Miscanthus for the of a sas with value, La biomasse est une source d'énergie renouvelable qui capte et stock le CO2. Les objectifs de ce travail ont été d'étudier les comportements thermiques de la biomasse et de ses constituants (cellulose, hémicellulose et lignine). Nous nous sommes plus particulièrement intéressés aux mécanismes de dégradation thermique des polymères naturels survenant en premier dans les traitements thermiques(les mécanismes primaires). Ce travail a été réalisé dans le cadre de l'ACI "Biomasters" avec le soutien du crédit mutuel. Les comportements thermiques de différentes biomasses et de ses constituants ont été étudiés en utilisant la thermogravimétrie (ATG), la pyrolyse couplée à la spectrométrie de masse (Py-SM) et la pyrolyse couplée à la chromatographie gazeuse avec détection par spectrométrie de masse(Py-CG/SM). Nous avons montré, par ATG, que les comportements thermiques des constituants sont sensiblement différents et précisé leurs rôles dans la dégradation thermique. Nous avons aussi montré l'impossibilité de proposer des lois prévisionnelles du comportement thermique d'une biomasse sur la base des résultats obtenus pour ses constituants. En Py-SM nous avons développé une méthode permettant de mettre en évidence les fragments moléculaires les plus représentatifs de la dégradation thermique. Ceci nous a permis de préciser les constituants les plus sensibles à l'action de catalyseurs métalliques. L'analyse Py-CG/SM des mélanges a montré que les compositions des vapeurs dans les mélanges sont proches de lois d'addition simples. Nous terminons notre travail par une application de la pyrolyse / gazéification du Miscanthus pour la production d'un gaz à bonne valeur énergétique

Published
2009

24. Primary stages study for lignocellulosic biomass thermal degradation

Author

Khelfa, Anissa and UL, Thèses

Subjects
Mécanismes primaires, [CHIM.OTHE] Chemical Sciences/Other, Biomasse, Pyrolyse, Py-SM, ATG
Abstract

Biomass is a renewable energy source, which collect and stock CO2. The objectives of this work were to study the thermal behavior of natural biomass and its components (cellulose, hemicellulose and lignin). We were particularly interested in the thermal degradation mechanisms of natural polymers arising, first, during heat treatments (primary mechanisms). This work was carried out with in the framework of the ACI "Biomasters" with the support of Credit Mutuel. The thermal behaviors of biomass and its components were studied by using thermogravimetry (TGA), pyrolysis coupled with mass spectrometry(Py-MS) and pyrolysis coupled with gas chromatography with detection by mass spectrometry (Py-GC/MS). The thermal behaviors of biomass components were shown, by TGA, to be appreciably different and their roles were specified in thermal degradation. We also showed the impossibility of proposing estimated laws of biomass thermalbehavior on the basis of the main component TGA results. With Py-MS, we developed a method allowing to highlight the most representative molecular fragments evolved during biomass thermal degradation. This enabled us to specify the most sensitive components towards metallic catalystaction. The Py-CG/SM analysis of the mixtures showed that vapor compositions in the mixtures are close to simple laws of addition. We complete our work by an application of pyrolysis/gasification of Miscanthus for the of a sas with value, La biomasse est une source d'énergie renouvelable qui capte et stock le CO2. Les objectifs de ce travail ont été d'étudier les comportements thermiques de la biomasse et de ses constituants (cellulose, hémicellulose et lignine). Nous nous sommes plus particulièrement intéressés aux mécanismes de dégradation thermique des polymères naturels survenant en premier dans les traitements thermiques(les mécanismes primaires). Ce travail a été réalisé dans le cadre de l'ACI "Biomasters" avec le soutien du crédit mutuel. Les comportements thermiques de différentes biomasses et de ses constituants ont été étudiés en utilisant la thermogravimétrie (ATG), la pyrolyse couplée à la spectrométrie de masse (Py-SM) et la pyrolyse couplée à la chromatographie gazeuse avec détection par spectrométrie de masse(Py-CG/SM). Nous avons montré, par ATG, que les comportements thermiques des constituants sont sensiblement différents et précisé leurs rôles dans la dégradation thermique. Nous avons aussi montré l'impossibilité de proposer des lois prévisionnelles du comportement thermique d'une biomasse sur la base des résultats obtenus pour ses constituants. En Py-SM nous avons développé une méthode permettant de mettre en évidence les fragments moléculaires les plus représentatifs de la dégradation thermique. Ceci nous a permis de préciser les constituants les plus sensibles à l'action de catalyseurs métalliques. L'analyse Py-CG/SM des mélanges a montré que les compositions des vapeurs dans les mélanges sont proches de lois d'addition simples. Nous terminons notre travail par une application de la pyrolyse / gazéification du Miscanthus pour la production d'un gaz à bonne valeur énergétique

Published
2009

26. Catalytic pyrolysis and gasification of Miscanthus Giganteus: Haematite (Fe2O3) a versatile catalyst

Author

Khelfa, Anissa, Sharypov, Victor, Finqueneisel, Gisèle, and Weber, Jean Victor

Subjects
*PYROLYSIS, *CHEMICAL reactions, *METALLIC oxides, *AROMATIC compounds
Abstract

Abstract: The present work describes the catalytic steam gasification and pyrolysis of Miscanthus×Giganteus pellets. Alone or in combination, pyrolysis and gasification catalytic processes lead nowadays to promising methods for the production of energy and chemicals from various biomass. In our best conditions, steam gasification at 850°C in the presence of 3wt.% haematite, leads to 94.8wt.% of gases and 5.2wt.% liquids in 20min. The gases composition (vol%) was: H2—45.7, CO—34.1, CO2—14.7, CH4—4.2 and others—1.3. In the presence of steam, haematite an iron oxide used as catalyst is active in the gasification and hydrogen production, is able to breakdown the tar produced during the thermal degradation of the biomass and leads to the partial oxidation of phenols. The influence of catalyst in pyrolysis is limited and only a decrease in liquids yields is observed. [Copyright &y& Elsevier]

Published
2009
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27. List of Contributors

Author

Abdelfatah, Rehab, Abdelmoez, Weal, Alonso, Jose L., Azuma, Jun-ichi, Bastos, Erick L., Bendicho, Carlos, Brahim, Marwa, Casas, María Parada, Conde Piñeiro, Enma, Domínguez González, Herminia, Díaz Reinoso, Beatriz, Flórez-Fernández, Noelia, Fujii, Satoshi, Gil, Marta, Gilbert-López, Bienvenida, Gómez, Belén, Gonçalves, Letícia C.P., González Muñoz, María Jesús, Goto, Motonobu, Greiner, Ralf, Herrero, Miguel, Hiraoka, Masanori, Ibáñez, Elena, Kanda, Hideki, Khelfa, Anissa, Koubaa, Mohamed, Lavilla, Isela, Machmudah, Siti, Mendiola, Jose A., Míguez, Beatriz, Mission, Elaine G., Nikmaram, Nooshin, Onda, Ayumu, Orsat, Valerie, Ozturk, Bulent, Plaza, Merichel, Quitain, Armando T., Rodríguez Seoane, Paula, Roohinejad, Shahin, Routray, Winny, Sasaki, Mitsuru, Soto-Maldonado, Carmen, Tsubaki, Shuntaro, Wada, Yuji, Wahyudiono, Wianowska, Dorota, Yáñez, Remedios, and Zúñiga-Hansen, María Elvira

Published
2017
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