Microwave-assisted extraction of mucilage from juá: Characterization and antioxidant activity.

Microwave-assisted extraction of mucilage from juá was investigated using response surface methodology. The optimal conditions for extraction were a power of 300 W, an extraction time of 240 s, a pH of 8.0, and a water/sample ratio of 1/6, which achieved a 26.43% yield. The monosaccharide composition and antioxidant activity of the mucilage from juá fruits from different regions of Caatinga were investigated. The fruits from Agreste Paraibano showed the highest mucilage extraction yield (18.64%) compared to that of fruits from Mata Paraibana (MP) (12.37%), Borborema (BB) (11.47%), and Sertão Paraibano (8.31%) (p < 0.05). Glucose (32.8%-50.8%) and arabinose (19.3%-32.9%) were the main monosaccharides found in juá mucilage. The mucilage from fruits in the MP presented the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl and oxygen radical absorbance capacity assays. Our results demonstrated the potential for the future exploration and application of juá mucilage in the food industry. PRACTICAL APPLICATION: Juá (Ziziphus joazeiro Mart.) mucilage contains phenolic compounds and antioxidant activity, and its extraction by MAE is efficient, as it contributed to a higher yield.

Bioaccessibility of phenolic compounds in native and exotic frozen pulps explored in Brazil using a digestion model coupled with a simulated intestinal barrier.

The bioaccessibility of phenolics and antioxidant activity were determined in açaí, cupuaçu, blackberry, blueberry, jabuticaba, raspberry, cajá and soursop frozen pulps (FPs) using a digestion model coupled with a simulated intestinal barrier. Cyanidin 3-glucoside (6.56%) and pelargonidin 3-glucoside (28.33%) were bioaccessible in blueberry and raspberry. Catechin had the highest bioaccessibility in blueberry (270.71%), blackberry (137.51%), and jabuticaba (99.52%), while the highest bioaccessibility of epicatechin (153.59%) and syringic acid (147.14%) was observed in blueberry. Procyanidin B1 presented the highest bioaccessibility in cajá (102.79%) and blackberry (87.62%) and contributed to the high DPPH▪ scavenging activity observed in these FPs. The bioaccessible fraction in soursop consisted of caffeic (8.18%), p-coumaric (7.36%), caftaric (7.96%) and chlorogenic (11.08%) acids, and these acids were correlated with the iron reduction capacity of this FP. Our study assessed the bioaccessible phenolics in several FPs and showed that those found in cajá and blackberry possesses the highest antioxidant activity.