RESUMO

In this work, polyphenols from Moringa oleifera (Mor) leaves were extracted by microwave-assisted extraction (MAE) and encapsulated by spray-drying (SD). Particularly, we explored the influence of tragacanth gum (TG), locust bean gum (LBG), and carboxymethyl-cellulose (CMC) as wall-materials on the physicochemical behavior of encapsulated Mor. Single or combined wall-material treatments (100:00 and 50:50 ratios, and total solid content 1%) were tested. The results showed the wall-material had a significant effect on the process yield (55.7-68.3%), encapsulation efficiency (24.28-35.74%), color (yellow or pale-yellow), total phenolic content (25.17-27.49 mg GAE g-1 of particles), total flavonoid content (23.20-26.87 mg QE g-1 of particles), antioxidant activity (DPPH• = 5.96-6.95 mg GAE g-1; ABTS•+ = 5.61-6.18 mg TE g-1 of particles), and particle size distribution (D50 = 112-1946 nm) of the encapsulated Mor. On the other hand, SEM analysis showed smooth and spherical particles, while TGA and DSC analyses confirmed the encapsulation of bioactive compounds based on the changes in thermal peaks. Finally, XRD analysis showed that the particles have an amorphous behavior. The encapsulated Mor produced with individual TG or CMC demonstrated better properties than those obtained from mixed gums. Thus, TG or CMC might be feasible wall materials for manufacturing encapsulated Mor that conserve the phenolic content and antioxidant activity.

Assuntos

RESUMO

Plant-based pigments are widely present in nature, they are classified depending on their chemical structure as tetrapyrroles, carotenoids, polyphenolic compounds, and alkaloids and are extensively used in medicine, food industry, clothes, and others. Recently they have been investigated due to their role in the areas of food processing, food safety and quality, packaging, and nutrition. Many studies indicate a relationship between bioactive pigments and Non-Communicable Diseases derived from oxidative stress. Their biological applications can help in preventing oxidative injuries in the cell caused by oxygen and nitrogen reactive species. Those pigments are easily degraded by light, oxygen, temperature, pH conditions, among others. Nanotechnology offers the possibility to protect bioactive ingredients and increase its bioavailability after oral administration. Safety to humans (mainly evaluated from toxicity data) is the first concern for these products. In the present work, we present a comprehensive outlook of the most important plant-based pigments used as food colorants, the principal nanotechnology systems prepared with them, and the relationship of these compounds with the oxidative stress and related Non-Communicable Disease.

Assuntos

RESUMO

Physicochemical, antifungal and antioxidant properties of a pectin - aloe mucilage - candelilla wax - Larrea tridentata polyphenols based bioactive film were evaluated. Antifungal capacity was analyzed against Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium oxysporum and Alternaria alternata. The main antioxidants in Larrea tridentata polyphenols were identified by HPLC-MS. Water vapor permeability (WVP) was measured in the film. Antioxidant capacities for ABTS· +, DPPH·, lipid oxidation inhibition (LOI) and ferric reducing antioxidant power (FRAP) (97, 92, and 57 %, 0.73 mM Fe, respectively) were evaluated. It was possible to determine the MIC50 for the fungi evaluated at concentrations of 558-612 ppm of polyphenols. Antioxidants identified were nordihydroguaiaretic acid (NDGA), Quercetin, and Kaenpherol. Treatment with 1.1 % of pectin, 0.16 % candelilla wax, 0.3 % glycerol, 5 % AM and 4 % extract of polyphenols showed values of thickness and WVP suitable to be applied on model fruits.