Spray-Drying Microencapsulation of Bauhinia ungulata L. var. obtusifolia Aqueous Extract Containing Phenolic Compounds: A Comparative Study Using Different Wall Materials.

Species belonging to the Bauhinia genus, usually known as "pata-de-vaca", are popularly used to treat diabetes. Bauhinia ungulata var. obtusifolia (Ducke) Vaz is among them, of which the leaves are used as a tea for medicinal purposes in the Amazon region. A microencapsulation study of lyophilized aqueous extract from Bauhinia ungulata leaves, which contain phenolic compounds, using five different wall materials (maltodextrin DE 4-7, maltodextrin DE 11-14; ß-cyclodextrin; pectin and sodium carboxymethylcellulose) is described in this paper. The microstructure, particle size distribution, thermal behavior, yield, and encapsulation efficiency were investigated and compared using different techniques. Using high-performance liquid chromatography, phenolics, and flavonoids were detected and quantified in the microparticles. The microparticles obtained with a yield and phenolics encapsulation efficiency ranging within 60-83% and 35-57%, respectively, showed a particle size distribution between 1.15 and 5.54 µm, spherical morphology, and a wrinkled surface. Among them, those prepared with sodium carboxymethylcellulose or pectin proved to be the most thermally stable. They had the highest flavonoid content (23.07 and 21.73 mg RUTE/g Extract) and total antioxidant activity by both the DPPH (376.55 and 367.86 µM TEq/g Extract) and ABTS (1085.72 and 1062.32 µM TEq/g Extract) assays. The chromatographic analyses allowed for quantification of the following substances retained by the microparticles, chlorogenic acid (1.74-1.98 mg/g Extract), p-coumaric acid (0.06-0.08 mg/g Extract), rutin (11.2-12.9 mg/g Extract), and isoquercitrin (0.49-0.53 mg/g Extract), compounds which considered to responsible for the antidiabetic property attributed to the species.

Microencapsulation by Spray Drying and Antioxidant Activity of Phenolic Compounds from Tucuma Coproduct (Astrocaryum vulgare Mart.) Almonds.

The industrial processing of fruits in the Amazon region, such as tucuma, generates a large amount of coproducts with great nutritional potential. In this work, phenolic compounds from tucuma coproduct almonds were extracted and microencapsulated by spray drying using maltodextrin as the encapsulating agent and verified its antioxidant activity. Phenolic compounds were determined by UV spectroscopy and identified by Ultraefficiency Liquid Chromatography. Antioxidant activity was measured by ABTS and DPPH assay. Thermogravimetric techniques, infrared spectroscopy, scanning electron microscopy, moisture content and water activity were applied to characterize the microparticle. The crude extract and microparticle had total polyphenols of 135.1 mg/g ± 0.078 and 130.5 mg/g ± 0.024, respectively. Caffeic and gallic acids were identified. The crude extract and the microparticle showed good antioxidant activity by ABTS and DPPH assay, justified by the presence of the phenolic compounds found. The microparticle showed spherical and heterogeneous structures and good encapsulation efficiency from the spray drying process using maltodextrin. The results show that the extract of the tucuma almond coproduct can be used as a phenolic compound-rich source and microencapsulated with possible application for functional food production.