Extraction of Polyphenolics from Plant Material for Functional Foods—Engineering and Technology
Notice bibliographique
Résumé
Polyphenolic substances or polyphenols include many classes of compounds ranging from phenolic acids, colored anthocyanins, simple flavonoids, and complex flavonoids. Polyphenolics contribute to the bitterness and astringency of fruits and fruit juices due to the interaction between polyphenolics, mainly procyanidins, and the glycoproteins in saliva. Polyphenols contribute largely to cellular processes within the body. In terms of pharmacological activity, they act against the oxidation of high-density lipoproteins (HDLs). Hence, they help the body retain important HDL while helping it get rid of problematic low-density lipoproteins (LDLs). In addition, polyphenols have also been found to have antiulcer, anticarcinogenic, and antimutagenic activities. The reason behind these activities is polyphenol's strong antioxidant power because they are able to quench free radicals. Green tea and grape seed extracts provide a superior source of monomers that are relatively inexpensive to extract. Comparatively, pine bark and other fruits extracts have low levels of monomers. Therefore, the nutraceutical industry has focused on optimizing extraction processes for green tea leaves and grape pomace, skins, and seeds. During extraction, a solvent is mixed with the plant material (grape seeds, grape skins, pine bark, or tea leaves). Extraction can be either completed by the addition of a solvent to the sample in a container and then removed by drying, or the solvent can be removed by concentration by ultrafiltration (UF). After any one of these processes, the extract must be dried to obtain a powder form. Alternatively, supercritical fluid extraction (SFE) can also be used, which produces the final product as a powder without any use of final drying. Organic solvent extraction is efficient and simple, yet costly. Large amounts of organic solvents are needed. This, in turn, is also detrimental to human use because traces of the organic solvent are present in the polyphenol extract. Polyphenol separation and concentration by membrane separation is even more efficient than organic solvent extraction. Organic solvents are still used but in lower quantities, and UF ensures the purity of the polyphenol extract. The drawback is membrane fouling, which can disrupt the process, and the time it takes to complete the process. The separation process has to be repeated several times. Supercritical fluid extraction is the extraction process of the future. CO2 is low cost, nontoxic, nonflammable, and noncorrosive, making it the perfect solvent for natural products. In the U.S. market, where $141 million was spent on grape seed products in 1999, it is imperative that safe and efficient extraction procedures are delivered that guarantee a pure polyphenol product.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».