Replacing synthetic antioxidants in food emulsions with microparticles from green acerola (Malpighia emarginata)

•The aqueous extracts of acerola fruits showed a high concentration of ascorbic acid (32.52 to 41.11 mg.100 mg−1).•Green acerola extracts ranged from 154.24 to 165.15 µM TEAC.100 mg−1 ABTS analysis.•The microparticles presented a retention of 88% of ascorbic acid.•The acerola microparticles showed protective effects on oil-in-water emulsions oxidation.•The microparticles had no sensory effect compared to synthetic antioxidants. Among natural extracts with antioxidant potential, acerola fruit is an important source of bioactive compounds. The goal of this work was to evaluate the antioxidant capacity of microencapsulated and lyophilized extracts of unripe acerola fruits produced under environmentally friendly conditions. In vitro antioxidant activity was determined, and products were applied in oil-in-water emulsions. Lipid oxidation products were measured by the absorptivity at 232 nm and hydroperoxide content. Sensory characteristics resulting from the addition of acerola microparticles to emulsions were also investigated. The aqueous extracts of acerola fruits showed a high concentration of ascorbic acid (32.52 to 41.11 mg.100 mg−1) and reducing power; the retention of ascorbic acid was 88% after spray drying. Oxidation inhibition was observed upon emulsion addition of acerola products: the hydroperoxide content after 9 days under accelerated conditions in the control samples was 14.03 mmol. L−1 and from 3.02 to 3.60 mmol. L−1 in samples with TBHQ or acerola microparticles (100-200 mg.kg−1). In addition, the microparticles did not show sensory effects compared to synthetic antioxidants. Acerola microparticles obtained after simple water extraction from green fruits were effective and are a potential new ingredient for the oxidative stability of lipid emulsions.