Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
J AOAC Int ; 105(2): 333-345, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35040962

RESUMEN

The Codex Alimentarius Commission, a central part of the joint Food and Agricultural Organization/World Health Organizations Food Standards Program, adopts internationally recognized standards, guidelines, and code of practices that help ensure safety, quality, and fairness of food trade globally. Although Codex standards are not regulations per se, regulatory authorities around the world may benchmark against these standards or introduce them into regulations within their countries. Recently, the Codex Committee on Nutrition and Foods for Special Dietary Uses (CCNFSDU) initiated a draft revision to the Codex standard for follow-up formula (FUF), a drink/product (with added nutrients) for young children, to include requirements for limiting or measuring the amount of sweet taste contributed by carbohydrates in a product. Stakeholders from multiple food and beverage manufacturers expressed concern about the subjectivity of sweetness and challenges with objective measurement for verifying regulatory compliance. It is a requirement that Codex standards include a reference to a suitable method of analysis for verifying compliance with the standard. In response, AOAC INTERNATIONAL formed the Ad Hoc Expert Panel on Sweetness in November 2020 to review human perception of sweet taste, assess the landscape of internationally recognized analytical and sensory methods for measuring sweet taste in food ingredients and products, deliver recommendations to Codex regarding verification of sweet taste requirements for FUF, and develop a scientific opinion on measuring sweet taste in food and beverage products beyond FUF. Findings showed an abundance of official analytical methods for determining quantities of carbohydrates and other sweet-tasting molecules in food products and beverages, but no analytical methods capable of determining sweet taste. Furthermore, sweet taste can be determined by standard sensory analysis methods. However, it is impossible to define a sensory intensity reference value for sweetness, making them unfit to verify regulatory compliance for the purpose of international food trade. Based on these findings and recommendations, the Codex Committee on Methods of Analysis and Sampling agreed during its 41st session in May 2021 to inform CCNFSDU that there are no known validated methods to measure sweetness of carbohydrate sources; therefore, no way to determine compliance for such a requirement for FUF.


Asunto(s)
Ingredientes Alimentarios , Bebidas , Dieta , Alimentos Formulados , Humanos , Gusto
2.
Biomaterials ; 27(5): 745-51, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16102811

RESUMEN

Chemical stabilization resulting in increased resistance to proteolytic degradation is one of the approaches in prevention of post-implantational aneurysm development in decellularized natural vascular scaffolds. Recently, tannic acid (TA) and tannic acid mimicking dendrimers (TAMD) have been suggested as potential stabilization agents for collagen and elastin. The aim of this work was to determine the stabilizing effects of TAMD on decellularized natural scaffolds. Vascular scaffolds fabricated from small intestine submucosa (SIS) and SIS plane sheets (Cook Biotech Inc.) were used. The biomechanical properties of the SIS vascular graft segments treated with TA and TAMD were tested. The effect of TAMD treatment on resistance to proteolytic degradation was evaluated by measuring biomechanical properties of TAMD stabilized and non-stabilized SIS specimens after incubation in collagenase solution. It was shown that treatment with TA as well as with TAMD increased the strength of tubular SIS as well as their resistance to proteolytic biodegradation manifested by preservation of biomechanical properties after collagenase treatment. Transmission electron microscopy demonstrated that treatment with TAMD increased the periodical pattern typical of collagen fiber ultrastructure as a result of the "mordant" effect. The possible collagen cross-linking effect of TAMD on SIS was investigated by differential scanning calorimetry (DSC). The treatment with TAMD induced a small, but detectable cross-linking effect, suggesting that TAMD do not establish extensive covalent cross links within the extracellular matrix but rather interact with collagen, thus rendering SIS scaffolds more resistant to proteolytic degradation.


Asunto(s)
Dendrímeros/química , Dendrímeros/farmacología , Intestino Delgado/efectos de los fármacos , Nanoestructuras/química , Taninos/química , Taninos/farmacología , Aneurisma/prevención & control , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Rastreo Diferencial de Calorimetría , Colágeno/metabolismo , Colagenasas/metabolismo , Elasticidad , Elastina/metabolismo , Temperatura , Trasplantes/efectos adversos
3.
Org Biomol Chem ; 2(14): 2113-24, 2004 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-15254640

RESUMEN

Dendrimers based on the 3,5-di-(2-aminoethoxy)-benzoic acid branching unit were used to attach multiple copies of a GM1 mimic for inhibition of cholera toxin binding. Systems up to octavalent were synthesized along with relevant reference compounds that contained in one case the ligand in a monovalent format and in another case the scaffold but not the ligand. Using a surface plasmon resonance inhibition assay the prepared inhibitors showed good inhibition. While the monovalent GM1 mimic showed the expected inhibition in the 200 microM range the multivalent scaffolds led to increased binding. The tetravalent compound was shown to be 440-fold more potent than its monovalent counterpart. The octavalent analog, however, was the most potent compound as determined using an ELISA assay.


Asunto(s)
Toxina del Cólera/antagonistas & inhibidores , Gangliósido G(M1)/química , Gangliósido G(M1)/síntesis química , Imitación Molecular , Benzoatos/síntesis química , Benzoatos/química , Secuencia de Carbohidratos , Toxina del Cólera/química , Ensayo de Inmunoadsorción Enzimática , Ligandos , Datos de Secuencia Molecular , Estructura Molecular , Resonancia por Plasmón de Superficie/métodos
4.
Org Biomol Chem ; 1(5): 803-10, 2003 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-12929363

RESUMEN

New and rigid multivalent lactose molecules were prepared. The structures contain lactose-2-aminothiazoline units at the periphery that were formed from a cyclisation of the thiourea sulphur onto the triple bond of the spacer. The lactosides were evaluated as inhibitors against lectin binding in a solid phase inhibition assay. In this assay the glycoprotein asialofetuin was immobilized onto the surface of microtiter plate wells, mimicking cell surface presentation, while mammalian galectins-1, -3 or -5 were in solution. Between the three galectins, the folding pattern and sequence are closely related but the topology of presentation of the carbohydrate recognition domains differs. Strong multivalency effects were observed for the tetravalent lactoside in the inhibition of galectin-3 binding with enhancements of almost 4300-fold compared to lactose. Remarkable selectivity was obtained in the inhibition since relative potencies of the tetravalent lactoside with the proto type galectins-1 and -5 did not exceed a factor of 143 relative to lactose. The binding of the lactosides to galectin-3 was also studied by fluorescence spectroscopy with all components in solution. These studies showed no multivalency effects in the inherent binding affinities.


Asunto(s)
Galectinas/química , Lactosa/química , Animales , Secuencia de Carbohidratos , Mamíferos , Datos de Secuencia Molecular , Espectrometría de Fluorescencia , Espectrometría de Masa por Ionización de Electrospray
5.
Bioorg Med Chem Lett ; 12(12): 1567-70, 2002 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-12039563

RESUMEN

Inspired by the structure of tannic acid, first- to third-generation dendrimers containing two, four, and eight galloyl moieties were synthesized. Stability, antioxidant activity and collagen cross-linking activity of the natural product and its dendrimer analogues were compared. The experimental results indicate that polygalloyl dendrimers might be used as new lead compounds to improve the long-term healing characteristics of burn wounds.


Asunto(s)
Ácido Gálico/química , Taninos Hidrolizables/química , Imitación Molecular , Antioxidantes/química , Antioxidantes/farmacología , Taninos Hidrolizables/farmacología
6.
Org Lett ; 4(10): 1807-8, 2002 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-12000304

RESUMEN

[structure: see text] During the search for improved monovalent ligands for cholera toxin (CT), a new lactose-2-aminothiazoline conjugate was discovered. In a fluorescence binding assay the compound was found to be one of the strongest relatively simple CT ligands to date with a K(d) of 23 microM.


Asunto(s)
Toxina del Cólera/química , Disacáridos/química , Tiazoles/química , Secuencia de Carbohidratos , Ligandos , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA