Microencapsulation of Tecoma stans Extracts: Bioactive Properties Preservation and Physical Characterization Analysis.

Bioactive compounds from medicinal plants have applications in the development of functional foods. However, since they are unstable, encapsulation is used as a conservation alternative. This work aimed to assess the bioactive properties (antioxidant and hypoglycemic) of different extracts, including the infusion, as well as their spray-dried microencapsulates from Tecoma stans leaves. A factorial design was proposed to determine the best extraction conditions, based on ABTS and DPPH inhibition. Maltodextrin (MD), arabic gum (AG), and a 1:1 blend (MD:AG) were used as encapsulating agents. Moreover, characterization through physicochemical properties, gas chromatography/mass spectrometry (GC-MS) and scanning electron microscopy (SEM) of the best two powders based on the bioactive properties were analyzed. The results showed that the combination of stirring, water, and 5 min provided the highest inhibition to ABTS and DPPH (35.64 ± 1.25 mg Trolox/g d.s. and 2.77 ± 0.01 g Trolox/g d.s., respectively). Spray drying decreased the antioxidant activity of the extract while preserving it in the infusion. The encapsulated infusion with MD:AG had the highest hypoglycemic activity as it presented the lowest glycemic index (GI = 47). According to the results, the microencapsulates could potentially be added in foods to enhance nutritional quality and prevent/treat ailments.

Total phenolics and antioxidant activity of Piper auritum and Porophyllum ruderale.

Extracts from fresh and dried samples of Mexican pepperleaf (Piper auritum Kunth) and "papalo" (Porophyllum ruderale) were obtained using a stirring or an ultrasound extraction system with five types of solvents (water, 50:50% v/v ethanol:water, 70:30% v/v ethanol:water, 85:15% v/v ethanol:1.5N HCl, and ethanol). Total phenolic compounds and antioxidant activity were evaluated with the phenol Folin Ciocalteu reagent and the ABTS method, respectively. Total phenolic compounds (PC), trolox (T), and ascorbic acid (AA), in the two herbs, were in the range of 6.79-68.03mg of galic acid (GA)/g dry solids (d.s.), 4.88-64.99mg of T/gd.s., and 5.31-49.84mgAA/gd.s., respectively. Extracts from fresh "papalo", using ultrasound as the extraction system, had the highest amount of total phenolic compounds. The fresh pepperleaf extract, obtained using ultrasound as the extraction method contained the highest amount of antioxidant activity.