Pectin-based aerogel particles for drug delivery: Effect of pectin composition on aerogel structure and release properties.

In this work, nanostructured pectin aerogels were prepared via a sol-gel process and subsequent drying under supercritical conditions. To this end, three commercially available citrus pectins and an in-house produced and enzymatically modified watermelon rind pectin (WRP) were compared. Then, the effect of pectin's structure and composition on the aerogel properties were analysed and its potential application as a delivery system was explored by impregnating them with vanillin. Results showed that the molecular weight, degree of esterification and branching degree of the pectin samples played a main role in the production of hydrogels and subsequent aerogels. The developed aerogel particles showed high specific surface areas (468-584 m2/g) and low bulk density (0.025-0.10 g/cm3). The shrinkage effect during aerogel formation was significantly affected by the pectin concentration and structure, while vanillin loading in aerogels and its release profile was also seen to be influenced by the affinity between pectin and vanillin. Furthermore, the results highlight the interest of WRP as a carrier of active compounds which might have potential application in food and biomedical areas, among others.

Asthma and rhinitis induced by exposure to raw green beans and chards.

BACKGROUND: Although the vast majority of IgE-mediated allergic reactions to foods occurs through ingestion, a few cases of unexpected allergic reactions to foods may occur through the exposure to airborne food allergen particles. METHODS: Case reports. Skin prick tests and serum-specific IgE (CAP-FEIA) were used to identify specific IgE antibodies. Bronchial provocation tests were performed to determine the clinical relevance of inhaled exposure to raw and cooked green beans and raw chards. After demonstrating specific reactivity to them, SDS-PAGE and immunoblotting of raw and cooked green beans were carried out to identify relevant antigens. RESULTS: Three women developed bronchial asthma and rhinitis after exposure to raw green beans, and one of them also when exposed to raw chards. All women tolerated ingestion of green beans. Patients reported multiple episodes while handling these vegetables for cooking activities. Allergy to green beans and chards was demonstrated by skin testing and serum-specific IgE. Bronchial challenge test with these allergens showed positive responses to raw, but not cooked, green beans and chards. Oral food challenges with green beans (raw and cooked) and chards were negative in all patients. In order to further characterize the allergenic components of these extracts, SDS-PAGE and electroblotting studies were also performed. Immunoblots of raw and cooked green beans extract showed two IgE-binding bands with apparent molecular weights of 41.1 and 70.6 kD. Interestingly, a 47-kD IgE-binding protein was detected only in raw green bean extracts. CONCLUSIONS: We report three patients who developed asthma and rhinitis caused by exposure to raw, but not to cooked, green beans and chards in a non-occupational environment. Only minor differences of IgE reactivity between nitrocellulose-blotted raw and boiled green bean extract were found.