Bioactive compounds and antioxidant activities in the agro-industrial residues of acerola (Malpighia emarginata L.), guava (Psidium guajava L.), genipap (Genipa americana L.) and umbu (Spondias tuberosa L.) fruits assisted by ultrasonic or shaker extraction

Abstract

The aim of this study was to analyze the residue powders of Malpighia emarginata L., Psidium guajava L., Genipa americana L. and Spondias tuberosa L. regarding their total phenolic compounds contents, antioxidant activity (ABTS, DPPH and FRAP), soluble sugars, carotenoids, organic acids by HPLC-DAD/RID and individual phenolic compounds by the UPLC-QDa-MS system. The genipap residue had a high content of soluble sugars (422.72 ± 19.15 mg.g−1 DW), with a higher content of sucrose (170.83 ± 10.89 mg.g−1 DW). Nystose was found in the residues of guava (6.59 ± 0.56 mg.g−1 DW) and umbu (65.61 ± 2.31 mg.g−1 DW). The residues of acerola and umbu showed contents of β-carotene of 5.84 ± 0.01 mg.g−1 DW and 0.10 ± 0.05 mg.g−1 DW, respectively while high concentration (1116.00 ± 2.00 mg.100 g−1 DW) of tartaric acid was found in acerola residue and quinic acid (6340 ± 104.00 mg.100 g−1 DW) in umbu residue. Acetone (80%) and ultrasonic extraction were the best conditions for the residues of acerola, guava and genipap, however, for the umbu residue, extraction with shaker showed better results. The acerola and umbu residues showed higher yields of total phenolics, the values being 378.69–444.05 mg GAE.100 g−1 DW and 326.14–404.36 mg GAE.100 g−1 DW, respectively, as well as antioxidant activity. Naringenin was the individual phenolic compound with the highest concentration in the residue of acerola and genipap, vanillin in guava and rutin in umbu. Thus, residues powders from acerola, guava, genipap and umbu constitute potential sources of bioactive compounds, which could be used in the food, pharmaceutical and cosmetic industries.