16 research outputs found
Extraction of fruit juices by microwave hydrodiffusion : tests and nutritional juice quality
Le procĂ©dĂ© innovant dâhydrodiffusion par micro-onde a Ă©tĂ© testĂ© et validĂ© pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procĂ©dĂ© prĂ©sente des avantages au niveau technique : rapiditĂ© dâextraction, pas de prĂ©paration de lâĂ©chantillon, aucun auxiliaire de fabrication. Il permet lâobtention de jus Ă partir de fruits difficiles Ă presser, avec une pasteurisation « in line » et des produits se diffĂ©renciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsĂ© du fruit sous lâeffet de la vapeur produite in situ. A partir du fruit congelĂ©, la dĂ©structuration liĂ©e Ă la croissance des cristaux de glace facilite lâextraction. Les rendements le plus Ă©levĂ©s sont obtenus Ă partir de fruits congelĂ©s, et Ă basse puissance. Une partie de lâeau des fruits est convertie en vapeur, mais peut ĂȘtre rĂ©cupĂ©rĂ©e en utilisant un rĂ©frigĂ©rant, ce qui permet dâatteindre des rendements proches des rendements de jus obtenus avec un prĂ©traitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus prĂ©sent dans le fruit ou obtenus par pressurage. La composition du jus expulsĂ© des fruits change au cours de lâextraction. La concentration des composĂ©s prĂ©sents dans la chair et hydrosolubles (sucres, acides, acides phĂ©noliques) baisse nettement en fin dâextraction, tandis que les anthocyanes, prĂ©sentes dans lâĂ©piderme des raisins ou des prunes, montrent un pic de concentration lors de la phase dâexpulsion rapide des jus. La teneur en procyanidines est nettement plus Ă©levĂ©e que pour des jus obtenus par pressurageThe hydrodiffusion process was tested and validated for production of juices from grapes, apricots and plums. Its major advantages are speed, no sample preparation, no processing aid. It allows production of juices from hard-to-press fruits with an in line pasteurisation. The juices present original characteristics notable bright colours, texture, and a fresh fruit aroma.The juice is expulsed from the fruit by the pressure due to in situ vapour generation. The destructuration occuring in frozen fruits due to growth of ice crystals facilitate the juice expulsion. The highest yields are obtained from frozen fruits and at low power densities. Part of the water from the fruits is vaporised, and can be collected by use of a cooler, allowing to reach yields comparable to those obtained by pressing after an enzymatic pre-treatment. Juice composition is close to that of juice extracted by pressing, though with slightly lower concentrations of most soluble solids. The composition of juice changes along the extraction. The highly soluble compounds present in the fruit flesh mostly show a clear exhaustion at the end ofextraction. Anthocyans, present exclusively in the peel of the test fruits, present a maximum during the fast juice extraction phase. Procyanidin concentrations is much higher in juices obtained by hydrodiffusion than in conventional juice
Procédé novateur d'extraction de jus de fruits par micro-onde : viabilité de fabrication et qualité nutritionnelle des jus
The hydrodiffusion process was tested and validated for production of juices from grapes, apricots and plums. Its major advantages are speed, no sample preparation, no processing aid. It allows production of juices from hard-to-press fruits with an in line pasteurisation. The juices present original characteristics notable bright colours, texture, and a fresh fruit aroma.The juice is expulsed from the fruit by the pressure due to in situ vapour generation. The destructuration occuring in frozen fruits due to growth of ice crystals facilitate the juice expulsion. The highest yields are obtained from frozen fruits and at low power densities. Part of the water from the fruits is vaporised, and can be collected by use of a cooler, allowing to reach yields comparable to those obtained by pressing after an enzymatic pre-treatment. Juice composition is close to that of juice extracted by pressing, though with slightly lower concentrations of most soluble solids. The composition of juice changes along the extraction. The highly soluble compounds present in the fruit flesh mostly show a clear exhaustion at the end ofextraction. Anthocyans, present exclusively in the peel of the test fruits, present a maximum during the fast juice extraction phase. Procyanidin concentrations is much higher in juices obtained by hydrodiffusion than in conventional juicesLe procĂ©dĂ© innovant dâhydrodiffusion par micro-onde a Ă©tĂ© testĂ© et validĂ© pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procĂ©dĂ© prĂ©sente des avantages au niveau technique : rapiditĂ© dâextraction, pas de prĂ©paration de lâĂ©chantillon, aucun auxiliaire de fabrication. Il permet lâobtention de jus Ă partir de fruits difficiles Ă presser, avec une pasteurisation « in line » et des produits se diffĂ©renciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsĂ© du fruit sous lâeffet de la vapeur produite in situ. A partir du fruit congelĂ©, la dĂ©structuration liĂ©e Ă la croissance des cristaux de glace facilite lâextraction. Les rendements le plus Ă©levĂ©s sont obtenus Ă partir de fruits congelĂ©s, et Ă basse puissance. Une partie de lâeau des fruits est convertie en vapeur, mais peut ĂȘtre rĂ©cupĂ©rĂ©e en utilisant un rĂ©frigĂ©rant, ce qui permet dâatteindre des rendements proches des rendements de jus obtenus avec un prĂ©traitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus prĂ©sent dans le fruit ou obtenus par pressurage. La composition du jus expulsĂ© des fruits change au cours de lâextraction. La concentration des composĂ©s prĂ©sents dans la chair et hydrosolubles (sucres, acides, acides phĂ©noliques) baisse nettement en fin dâextraction, tandis que les anthocyanes, prĂ©sentes dans lâĂ©piderme des raisins ou des prunes, montrent un pic de concentration lors de la phase dâexpulsion rapide des jus. La teneur en procyanidines est nettement plus Ă©levĂ©e que pour des jus obtenus par pressurag
Procédé novateur d'extraction de jus de fruits par micro-onde (viabilité de fabrication et qualité nutritionnelle des jus)
Le procĂ©dĂ© innovant d hydrodiffusion par micro-onde a Ă©tĂ© testĂ© et validĂ© pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procĂ©dĂ© prĂ©sente des avantages au niveau technique : rapiditĂ© d extraction, pas de prĂ©paration de l Ă©chantillon, aucun auxiliaire de fabrication. Il permet l obtention de jus Ă partir de fruits difficiles Ă presser, avec une pasteurisation in line et des produits se diffĂ©renciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsĂ© du fruit sous l effet de la vapeur produite in situ. A partir du fruit congelĂ©, la dĂ©structuration liĂ©e Ă la croissance des cristaux de glace facilite l extraction. Les rendements le plus Ă©levĂ©s sont obtenus Ă partir de fruits congelĂ©s, et Ă basse puissance. Une partie de l eau des fruits est convertie en vapeur, mais peut ĂȘtre rĂ©cupĂ©rĂ©e en utilisant un rĂ©frigĂ©rant, ce qui permet d atteindre des rendements proches des rendements de jus obtenus avec un prĂ©traitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus prĂ©sent dans le fruit ou obtenus par pressurage. La composition du jus expulsĂ© des fruits change au cours de l extraction. La concentration des composĂ©s prĂ©sents dans la chair et hydrosolubles (sucres, acides, acides phĂ©noliques) baisse nettement en fin d extraction, tandis que les anthocyanes, prĂ©sentes dans l Ă©piderme des raisins ou des prunes, montrent un pic de concentration lors de la phase d expulsion rapide des jus. La teneur en procyanidines est nettement plus Ă©levĂ©e que pour des jus obtenus par pressurageThe hydrodiffusion process was tested and validated for production of juices from grapes, apricots and plums. Its major advantages are speed, no sample preparation, no processing aid. It allows production of juices from hard-to-press fruits with an in line pasteurisation. The juices present original characteristics notable bright colours, texture, and a fresh fruit aroma.The juice is expulsed from the fruit by the pressure due to in situ vapour generation. The destructuration occuring in frozen fruits due to growth of ice crystals facilitate the juice expulsion. The highest yields are obtained from frozen fruits and at low power densities. Part of the water from the fruits is vaporised, and can be collected by use of a cooler, allowing to reach yields comparable to those obtained by pressing after an enzymatic pre-treatment. Juice composition is close to that of juice extracted by pressing, though with slightly lower concentrations of most soluble solids. The composition of juice changes along the extraction. The highly soluble compounds present in the fruit flesh mostly show a clear exhaustion at the end ofextraction. Anthocyans, present exclusively in the peel of the test fruits, present a maximum during the fast juice extraction phase. Procyanidin concentrations is much higher in juices obtained by hydrodiffusion than in conventional juicesAVIGNON-Bib. numĂ©rique (840079901) / SudocSudocFranceF
Procédé novateur d'extraction de jus de fruits par micro-onde : viabilité de fabrication et qualité nutritionnelle des jus
The hydrodiffusion process was tested and validated for production of juices from grapes, apricots and plums. Its major advantages are speed, no sample preparation, no processing aid. It allows production of juices from hard-to-press fruits with an in line pasteurisation. The juices present original characteristics notable bright colours, texture, and a fresh fruit aroma.The juice is expulsed from the fruit by the pressure due to in situ vapour generation. The destructuration occuring in frozen fruits due to growth of ice crystals facilitate the juice expulsion. The highest yields are obtained from frozen fruits and at low power densities. Part of the water from the fruits is vaporised, and can be collected by use of a cooler, allowing to reach yields comparable to those obtained by pressing after an enzymatic pre-treatment. Juice composition is close to that of juice extracted by pressing, though with slightly lower concentrations of most soluble solids. The composition of juice changes along the extraction. The highly soluble compounds present in the fruit flesh mostly show a clear exhaustion at the end ofextraction. Anthocyans, present exclusively in the peel of the test fruits, present a maximum during the fast juice extraction phase. Procyanidin concentrations is much higher in juices obtained by hydrodiffusion than in conventional juicesLe procĂ©dĂ© innovant dâhydrodiffusion par micro-onde a Ă©tĂ© testĂ© et validĂ© pour la fabrication de jus de fruit sur des raisins, abricots et prunes. Ce procĂ©dĂ© prĂ©sente des avantages au niveau technique : rapiditĂ© dâextraction, pas de prĂ©paration de lâĂ©chantillon, aucun auxiliaire de fabrication. Il permet lâobtention de jus Ă partir de fruits difficiles Ă presser, avec une pasteurisation « in line » et des produits se diffĂ©renciant nettement des jus commerciaux par leur couleur et texture.Le jus est expulsĂ© du fruit sous lâeffet de la vapeur produite in situ. A partir du fruit congelĂ©, la dĂ©structuration liĂ©e Ă la croissance des cristaux de glace facilite lâextraction. Les rendements le plus Ă©levĂ©s sont obtenus Ă partir de fruits congelĂ©s, et Ă basse puissance. Une partie de lâeau des fruits est convertie en vapeur, mais peut ĂȘtre rĂ©cupĂ©rĂ©e en utilisant un rĂ©frigĂ©rant, ce qui permet dâatteindre des rendements proches des rendements de jus obtenus avec un prĂ©traitement enzymatique et pressurage. Globalement, le jus a une composition proche de celle du jus prĂ©sent dans le fruit ou obtenus par pressurage. La composition du jus expulsĂ© des fruits change au cours de lâextraction. La concentration des composĂ©s prĂ©sents dans la chair et hydrosolubles (sucres, acides, acides phĂ©noliques) baisse nettement en fin dâextraction, tandis que les anthocyanes, prĂ©sentes dans lâĂ©piderme des raisins ou des prunes, montrent un pic de concentration lors de la phase dâexpulsion rapide des jus. La teneur en procyanidines est nettement plus Ă©levĂ©e que pour des jus obtenus par pressurag
Different compounds are extracted with different time courses from fruits during microwave hydrodiffusion: examples and possible causes
International audienceWe set out to determine how nutrients diffuse during extraction, using fractional collection. The highest concentrations of sugars (195.5, 64.8 and 60.8 g/L, respectively for grape, 'Najbolia' plum and apricot) were found for the earliest stages of extraction, with a decrease in concentration (to 41.4 g/L, 48.2 g/L and 1.7 g/L, respectively) at the end of extraction process. Total polyphenols showed the same trends for plum and apricot (from 4.1 g/L to 2.9 g/L for 'Najbolia' plum, from 2.2 to 0.2 g/L for apricot) but highest concentrations of total polyphenols (for grape and cherry) were obtained at fraction 5 or 6 (out of 7). Carotenoids from cherry tomato also had highest concentrations (at circa 25 mg/L) almost at the end of extraction. For volatile molecules from sweet cherry, hexanal, 2-hexenal and linalool had their highest concentrations at fractions 3-4 (out of 7). Diffusion of nutrients depended on fruit destructuring, molecule solubility and localization of the compounds. Fruit size seemed unimportant
An innovative process for extraction of fruit juice using microwave heating
The objectives of this study were to evaluate the possibility of extracting juice from selected fruits (plum, apricot, grape) using microwaves and gravity, and to characterize this process. The process uses microwaves for hydrodiffusion of juice from the inside to the exterior of fruit material and earth gravity to collect the fruit juice outside the microwave cavity. The extraction kinetics were fitted by a descriptive model and the corresponding parameters were correlated to the operating conditions. Best yields were obtained at optimized microwave power and from frozen fruits respectively 480 ml kgâ1 for plums, 620 ml kgâ1 for grapes, and 550 ml kgâ1 for apricots. The obtained juices were brightly colored, as this method allows inactivation of endogenous enzymes such as polyphenol oxidase prior to fruit grinding. They were perceived as fairly acidic and for plum and grape presented detectable astringency. The present apparatus permitted fast and efficient extraction even from "hard to press" fruits such as plums and apricots, yielding an original, brightly coloured produc
Alternative process for strawberry juice processing: Microwave hydrodiffusion and gravity
MPTP animal model of Parkinsonism: dopamine cell death or only tyrosine hydroxylase impairment? - A study using PET imaging, autoradiography and immunohistochemistry in the cat.
International audienceAIMS: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin widely used to produce experimental models of Parkinson's disease in laboratory animals. It is believed to cause a selective destruction of substantia nigra dopamine neurons, mainly based on a large reduction of tyrosine hydroxylase (TH), the catecholamine's synthesizing enzyme. Unlike Parkinson's disease in humans, however, all animal models are able to recover more or less rapidly from the MPTP induced Parkinsonian syndrome. This raises the question as whether MPTP causes a cell death with a decrease in dopamine transporter or a simple impairment of TH. METHODS: To respond to this question, we quantified in a cat model of Parkinson's disease (MPTP 5 mg/kg i.p. during 5 days) the dopamine transporter using positron emission tomography (PET) imaging and autoradiography of [(11) C]PE2I and compared the data with the TH-immunoreactivity. RESULTS: We found no changes in [(11) C]PE2I PET binding either 5 or 26 days after MPTP treatment when compared to baseline levels. Similarly, there were no significant changes in [(11) C]PE2I autoradiographic binding in the cat brain one week after MPTP treatment. In sharp contrast, MPTP treated cats exhibited severe Parkinson-like motor syndrome during the acute period with a marked decrease in TH-immunoreactivity in the striatum. CONCLUSION: These data suggest that MPTP toxicity impairs efficiently TH and that such an effect is not necessarily accompanied by significant reduction of dopamine transporter seen with in vitro or in vivo [(11) C]PE2I binding