Effects of agave fructans as carrier agents on the encapsulation of blue corn anthocyanins using spray-drying were evaluated. Blue corn extract was mixed with 6%, 8%, 10%, and 12% (w/v) of agave fructans in duplicate and dried at 150 °C. The extract showed good contents of anthocyanins, polyphenols, and antioxidant activity. The increase of agave fructans in the encapsulated powders caused a significant increase (p < 0.05) in the humidity, water activity (a_w), pH, bulk density, water solubility index (WSI), and color L* values. On the contrary, the agave fructan addition decreased the hygroscopicity, water absorption index (WAI), antioxidant activity, total anthocyanin, total polyphenol, and individual anthocyanin contents. The encapsulation of blue corn extract with 6% agave fructans (w/v) resulted in good physical, thermal, morphological, and high antioxidant properties. The results suggest that the use of agave fructans as wall material represents advantages in the conservation of anthocyanins and other bioactive compounds from blue corn extract during their encapsulation. The application of blue corn anthocyanin encapsulated powders as a food ingredient is promising for food pigmentation, representing additional advantages for their contribution as a soluble fiber that can benefit the health of consumers.

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC; 22.2–35.7%), extrusion temperatures (ET; 102–142 °C), and screw speeds (SP; 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties; increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.

The addition of flaxseed and amaranth on the physicochemical, functional, and microstructural changes of instant-extruded products was evaluated. Six mixtures with different proportions of amaranth (18.7–33.1%), flaxseed (6.6–9.3%), maize grits (55.6–67.3%) and minor ingredients (4.7%) were extruded in a twin-screw extruder. Insoluble and soluble fiber contents in extrudates increased as the proportions of amaranth and flaxseed increased. However, the highest flaxseed proportion had the highest soluble fiber content (1.9%). Extruded products with the highest proportion of flaxseed and amaranth resulted in the highest dietary fiber content and hardness values (5.2 N), which was correlated with the microstructural analysis where the crystallinity increased, resulting in larger, and more compact laminar structure. The extruded products with the highest maize grits proportion had the highest viscosity, expansion, and water absorption indexes, and the lowest water solubility index values. The mixtures with amaranth (18.7–22.9%), flaxseed (8.6–9.3%), and maize grits (63.8–67.3%) resulted in extruded products with acceptable physicochemical and functional properties.

Physicochemical properties of a blend of 10% Aloe vera gel with 5% pitaya juice subjected to UV-C doses of 16.5, 27.7, and 40 mJ/cm² were evaluated at pH 3.5 and 5.5. Unprocessed treatments were used as the control. The a* color parameter decreased and luminosity increased at pH 3.5. The decrease in the reddish color was consistent with the decrease in total betalains content and stabilized at pH 5.5. The NMR analyses of UV-C treatments showed changes in betalains signal patterns. Polyphenolics content was significantly reduced in the UV-C treatments at pH 5.5. UV-C processing decreased the antioxidant activity 1.25 times compared to unprocessed treatments. Total sugar content was reduced as the UV-C dose increased. Doses above 16.5 mJ/cm² resulted in a higher simple sugar content at a pH 3.5. The UV-C continuous flow technology can be applied to stabilize betalains in Aloe vera–pitaya blends at a UV-C dose of 16.5 mJ/cm² and pH 5.5.

UV-C irradiation doses (12.8, 24.2, 35.8, and 54.6 mJ×cm-2) on the physicochemical and microbiological properties of 10% Aloe vera gel at different pHs (3.5, 4.5, and 5.5) were evaluated. An unprocessed treatment (UP) and a short (45 s) thermal treatment (TT) at 90 °C were used as controls. The irradiation doses and pH levels affected (p < 0.05) the elimination of coliforms and aerobic mesophilic microorganisms with the same efficiency as TT. Molds and yeasts were successfully eliminated at doses ≥24.2 mJ×cm-2 regardless of pH. Reducing sugars, total polyphenols, and aloin A content decreased as pH increased (p < 0.05). Although, the antioxidant activity was significantly reduced at doses ≥35.8 mJ×cm-2. TT and UV-C treatments affected the a* color parameter (p < 0.05), resulting the UV-C with the highest values. In both treatments, a reddish color was present at pH ≥ 4.5. The UV-C treatment resulted in minimal changes in most physicochemical properties, compared to UP treatment. However, TT significantly affected most physicochemical properties of A. vera gel blends. These results suggest that dose of 24.2 mJ×cm-2 in a continuous flow UV system is a non-thermal alternative for the stabilization of 10% A. vera gel blends at pH of 3.5. Se evaluaron las dosis de irradiación UV-C (12.8, 24.2, 35.8 y 54.6 mJ×cm-2) sobre las propiedades fisicoquímicas y microbiológicas de gel de Aloe vera al 10% a diferentes pHs (3.5, 4.5 y 5.5). Utilizando un tratamiento sin proceso (UP) y un tratamiento térmico (TT) (45 s; 90 °C) como controles. Las dosis y los niveles de pH afectaron (p <0.05) la eliminación de coliformes y mesófilos aerobios con la misma eficiencia que el TT. Los hongos y levaduras se eliminaron a dosis ≥24.2 mJ×cm-2 independientemente del pH. Azúcares reductores, polifenoles totales y el contenido de aloína A disminuyeron conforme aumentó el pH (p <0.05). Mientras que la actividad antioxidante se redujo significativamente a dosis ≥35.8 mJ×cm-2. Los tratamientos TT y UV-C afectaron el parámetro de color a* (p <0.05), resultando el UV-C con los valores más altos. En ambos tratamientos, se presentó una coloración rojiza a pH ≥ 4.5. El tratamiento con UV-C presentó cambios mínimos en la mayoría de las propiedades físicoquímicas, en comparación con el tratamiento UP. Sin embargo, el TT afectó significativamente la mayoría de las propiedades fisicoquímicas de las mezclas de gel de A. vera. Estos resultados sugieren que la dosis de 24.2 mJ×cm-2 en un sistema UV de flujo continuo es una alternativa no térmica para la estabilización de mezclas de gel de A. vera al 10% a pH de 3.5.