La flash-detente est un nouveau procede de transformation des fruits et legumes permettant l'... more La flash-detente est un nouveau procede de transformation des fruits et legumes permettant l'obtention de jus et de purees ayant des caracteristiques rheologiques et physico-chimiques differentes des produits traditionnels. Le procede peut etre scinde en deux etapes specifiques. Les fruits entiers sont dans un premier temps etuves de 60 a 90°C en fonction du materiel vegetal, puis subitement introduits dans une chambre sous vide (2-5 kPa). L'evaporation instantanee d'une partie de l'eau de constitution des fruits provoque un broyage fin du fruit par la creation de micro-canaux intercellulaires. L'etape d'etuvage permet d'inhiber l'activite enzymatique endogene tandis que l'etape de detente sous vide permet d'eviter les phenomenes d'oxydation et le brunissement qui en decoule. Le materiel vegetal ainsi traite presente une viscosite ainsi qu'une intensite colorante superieures a celles des produits traditionnels. Ce procede est deja industriellement applique pour le pre-traitement de la vendange avant fermentation ou pour la production de purees de tomate plus colorees et plus visqueuses. Trois fruits tropicaux (fruit de la passion, goyave et mangue) ont ete traites par le procede de flash-detente puis raffines. Nous avons etudie les polysaccharides et le comportement rheologique de ces produits en les comparant a des purees traditionnelles. Enfin, ce procede a aussi ete applique a l'extraction des huiles essentielles d'ecorces d'agrumes. (Resume d'auteur)
Toute technologie de transformation des fruits en produits derives peut favoriser la reduction de... more Toute technologie de transformation des fruits en produits derives peut favoriser la reduction des pertes apres recolte de fruits physiologiquement sains, voire de varietes ne repondant pas aux criteres imposes par les cahiers des charges et donc non commercialisables en frais. Ce chapitre traite des themes suivants : 1- produits de transformation (types de produits, importance de la transformation), 2- technologies d'elaboration des concentres : jus concentrables (agrumes, fruits de la passion, ananas), technologies de concentration (par evaporation, par couplage ultrafiltration (UF) / osmose inverse (OI)), techniques a l'etude), 3- technologies d'elaboration des purees : structure et composition des fruits concernes, etapes de transformation (classique, broyage par flash-detente), produits obtenus (purees, purees concentrees), 4- produits alimentaires intermediaires (PAI) : a partir des coproduits d'agrumes (huiles essentielles, pectines), papaine et bromelaine, PAI de type enzymatique (activites proteolytiques, nouvelles utilisations)
International Journal of Food Science and Technology, Oct 1, 2009
Physicochemical and morphological properties of ac¸ai powder produced with different carrier agen... more Physicochemical and morphological properties of ac¸ai powder produced with different carrier agents were evaluated in this work. Powders were produced by spray drying, using maltodextrin 10DE, maltodextrin 20DE, gum arabic and tapioca starch as carrier agents. Powder characterisation included analysis of moisture content, water activity, solubility, hygroscopicity, particle size distribution, morphology, total polyphenolics and antioxidant activity. Results showed that the samples produced with maltodextrin 20DE and gum arabic presented the smallest size and highest hygroscopicity. The powder produced with tapioca starch exhibited the lowest hygroscopity and solubility, and the highest mean diameter. With regard to morphology, all particles exhibited spherical and shrivelled surfaces, except those produced with tapioca starch, which exhibited rounded and smooth surfaces. Powders produced with maltodextrins and gum arabic showed high polyphenolic retention and antioxidant activity preservation after storage at 40 _C for 15 days, while for the particles produced with tapioca starch, this protective effect was less pronounced. (Résumé d'auteur
Pineapple fruit is a major horticultural crop in Rwanda. About 27 small scale pineapple processor... more Pineapple fruit is a major horticultural crop in Rwanda. About 27 small scale pineapple processors have entered into small business of processing different pineapple products such as juice, jam, jellies and dried pineapple slices. The aim of the present study is to assess the processing techniques used by small scale pineapple processors and to determine the microbial population present at raw pineapple surface and pineapple juice before and after sanitization. Small and medium enterprises were visited in July 2011. The results showed that pineapple processors use a number of preservatives in processed products to increase shelflife. Polyethylenterephtalate (PET) containers were used to package pineapple juice, jam and jelly. The PET containers were filled with products at 40°C. This resulted in products being microbiologically unstable. It is therefore advisable to fill the containers with products at 90°C to ensure microbial stability. Further, weighing of preservatives used may n...
The roots of Ulmus macrocarpa Hance (Ulmaceae) have been used as an oriental traditional medicine... more The roots of Ulmus macrocarpa Hance (Ulmaceae) have been used as an oriental traditional medicine for the treatment of inflammation, ulcers, cancers, and parasites. Activity guided isolation from the roots of U. macrocarpa yielded three flavonoids [catechin 7-O-β-D-apiofuranoside (1), (+)-catechin (2), taxifolin 6-C-glucopyranoside (3)], and one coumarin [fraxin (4)]. To investigate the antioxidative and anti-inflammatory effects of these compounds, DPPH radical scavenging activity and inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells were examined and the expression of inducible NO synthase (iNOS) and cyclooxidase-2 (COX-2) were measured by RT-PCR and Western Blotting in HaCaT cells. Compounds 1, 2, and 3 showed moderate antioxidative activities compared with L-ascorbic acid as a positive control. NO production was reduced and the expressions of iNOS and COX-2 and their mRNA were inhibited by the addition of samples (1-4). These results suggest that the phenolic compounds from the roots of U. macrocarpa might be developed as antioxidant and anti-inflammatory agents.
La flash-detente est un nouveau procede de transformation des fruits et legumes permettant l'... more La flash-detente est un nouveau procede de transformation des fruits et legumes permettant l'obtention de jus et de purees ayant des caracteristiques rheologiques et physico-chimiques differentes des produits traditionnels. Le procede peut etre scinde en deux etapes specifiques. Les fruits entiers sont dans un premier temps etuves de 60 a 90°C en fonction du materiel vegetal, puis subitement introduits dans une chambre sous vide (2-5 kPa). L'evaporation instantanee d'une partie de l'eau de constitution des fruits provoque un broyage fin du fruit par la creation de micro-canaux intercellulaires. L'etape d'etuvage permet d'inhiber l'activite enzymatique endogene tandis que l'etape de detente sous vide permet d'eviter les phenomenes d'oxydation et le brunissement qui en decoule. Le materiel vegetal ainsi traite presente une viscosite ainsi qu'une intensite colorante superieures a celles des produits traditionnels. Ce procede est deja industriellement applique pour le pre-traitement de la vendange avant fermentation ou pour la production de purees de tomate plus colorees et plus visqueuses. Trois fruits tropicaux (fruit de la passion, goyave et mangue) ont ete traites par le procede de flash-detente puis raffines. Nous avons etudie les polysaccharides et le comportement rheologique de ces produits en les comparant a des purees traditionnelles. Enfin, ce procede a aussi ete applique a l'extraction des huiles essentielles d'ecorces d'agrumes. (Resume d'auteur)
Toute technologie de transformation des fruits en produits derives peut favoriser la reduction de... more Toute technologie de transformation des fruits en produits derives peut favoriser la reduction des pertes apres recolte de fruits physiologiquement sains, voire de varietes ne repondant pas aux criteres imposes par les cahiers des charges et donc non commercialisables en frais. Ce chapitre traite des themes suivants : 1- produits de transformation (types de produits, importance de la transformation), 2- technologies d'elaboration des concentres : jus concentrables (agrumes, fruits de la passion, ananas), technologies de concentration (par evaporation, par couplage ultrafiltration (UF) / osmose inverse (OI)), techniques a l'etude), 3- technologies d'elaboration des purees : structure et composition des fruits concernes, etapes de transformation (classique, broyage par flash-detente), produits obtenus (purees, purees concentrees), 4- produits alimentaires intermediaires (PAI) : a partir des coproduits d'agrumes (huiles essentielles, pectines), papaine et bromelaine, PAI de type enzymatique (activites proteolytiques, nouvelles utilisations)
International Journal of Food Science and Technology, Oct 1, 2009
Physicochemical and morphological properties of ac¸ai powder produced with different carrier agen... more Physicochemical and morphological properties of ac¸ai powder produced with different carrier agents were evaluated in this work. Powders were produced by spray drying, using maltodextrin 10DE, maltodextrin 20DE, gum arabic and tapioca starch as carrier agents. Powder characterisation included analysis of moisture content, water activity, solubility, hygroscopicity, particle size distribution, morphology, total polyphenolics and antioxidant activity. Results showed that the samples produced with maltodextrin 20DE and gum arabic presented the smallest size and highest hygroscopicity. The powder produced with tapioca starch exhibited the lowest hygroscopity and solubility, and the highest mean diameter. With regard to morphology, all particles exhibited spherical and shrivelled surfaces, except those produced with tapioca starch, which exhibited rounded and smooth surfaces. Powders produced with maltodextrins and gum arabic showed high polyphenolic retention and antioxidant activity preservation after storage at 40 _C for 15 days, while for the particles produced with tapioca starch, this protective effect was less pronounced. (Résumé d'auteur
Pineapple fruit is a major horticultural crop in Rwanda. About 27 small scale pineapple processor... more Pineapple fruit is a major horticultural crop in Rwanda. About 27 small scale pineapple processors have entered into small business of processing different pineapple products such as juice, jam, jellies and dried pineapple slices. The aim of the present study is to assess the processing techniques used by small scale pineapple processors and to determine the microbial population present at raw pineapple surface and pineapple juice before and after sanitization. Small and medium enterprises were visited in July 2011. The results showed that pineapple processors use a number of preservatives in processed products to increase shelflife. Polyethylenterephtalate (PET) containers were used to package pineapple juice, jam and jelly. The PET containers were filled with products at 40°C. This resulted in products being microbiologically unstable. It is therefore advisable to fill the containers with products at 90°C to ensure microbial stability. Further, weighing of preservatives used may n...
The roots of Ulmus macrocarpa Hance (Ulmaceae) have been used as an oriental traditional medicine... more The roots of Ulmus macrocarpa Hance (Ulmaceae) have been used as an oriental traditional medicine for the treatment of inflammation, ulcers, cancers, and parasites. Activity guided isolation from the roots of U. macrocarpa yielded three flavonoids [catechin 7-O-β-D-apiofuranoside (1), (+)-catechin (2), taxifolin 6-C-glucopyranoside (3)], and one coumarin [fraxin (4)]. To investigate the antioxidative and anti-inflammatory effects of these compounds, DPPH radical scavenging activity and inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells were examined and the expression of inducible NO synthase (iNOS) and cyclooxidase-2 (COX-2) were measured by RT-PCR and Western Blotting in HaCaT cells. Compounds 1, 2, and 3 showed moderate antioxidative activities compared with L-ascorbic acid as a positive control. NO production was reduced and the expressions of iNOS and COX-2 and their mRNA were inhibited by the addition of samples (1-4). These results suggest that the phenolic compounds from the roots of U. macrocarpa might be developed as antioxidant and anti-inflammatory agents.
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