Bioactive potential of some fruit by-products: antioxidant, antimicrobial, and anti-inflammatory properties

BackgroundAgro-byproducts are substances that are produced by the bioprocessing sector that can offer functionality and bioactivity when included in food products. Currently, there is a growing interest in using by-products obtained from fruits and vegetables.ObjectiveIn the current study, We investigated the bioactive potential of some fruit by-products, including olive meal, Barbary fig peel, date seed, avocado peel and seed, mango peel and kernel, and apricot (kernel).Materials and methodsVarious organic solvents were utilized to extract plant parts (70% ethanol, 70% acetone, and hexane). Standard methods were used to measure the composite index for total antioxidant potency, (which was determined based on total phenols, total flavonoids, 1,1-Diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS)) antimicrobial activity, In vitro anti-inflammatory activity by human red blood cell membrane (HRBC), heat-induced hemolysis, and cytotoxicity assay with brine shrimp larvae (Artemia salina).Results and conclusionAcetone and ethanol extracts of mango kernel had the highest levels of phenolic compounds, while hexane extract of apricot kernel had the lowest amount. The inhibitory activity against DPPH radical was highest in the acetone extract of date seed, 68.12±1.16 μg/mL. On the other hand, the inhibitory activity against ABTS radical was highest in the acetone extract of mango kernel, 110.85±1.7 μg/mL. This trend was followed by the fruit by-product extracts' antioxidant potency composite index (ACI). The acetone extract of the mango kernel had the highest ACI, followed by its ethanolic extract due to the higher total phenolic content, that was found in these extracts. Avocado peel and seed had antibacterial effects against most of the pathogenic bacteria with different solvents. Anti-inflammatory HRBC stabilization was used to assess the in vitro approach. In this method, apricot kernel showed high anti-inflammatory properties with different solvents.Based on the obtained results, mango kernels, date seeds, and avocado peels can be recommended as potential natural sources of antioxidants that are suitable for use in the pharmaceutical field.