Macronutrient Composition of Peel and Seeds of Passiflora tripartita and Evaluation of Antioxidant Capacity, Antimicrobial Activity and Phenolic content in Fresh and Dehydrated Forms

Abstract

The aim of this study was to determine the antioxidant capacity, antimicrobial activity, and bioactive compounds of the fresh and dehydrated peel and seeds of Passiflora tripartita (tumbo serrano), as well as the macronutrient content in fresh peel and seeds. The fruits were harvested at a ‘pintón’ (semi-ripe) stage in Junín, Peru, and the seeds and peel were divided into two groups: fresh and dehydrated. The samples were extracted by maceration in 70% (v/v) ethanol and sonicated; their total phenolic (TPC) and flavonoid (TFC) contents were determined spectrophotometrically, and their antioxidant capacities were evaluated using the DPPH● and ABTS●+ radical scavenging assays. In addition, the antimicrobial activity against Escherichia coli was evaluated by the Kirby-Bauer disk diffusion test. The results indicate that the dehydrated seed extract exhibited the highest TPC (684.86 ± 31.55 mg gallic acid equivalents/g dry basis extract) and TFC (178.78 ± 5.22 mg quercetin equivalents/g dry basis extract), while the fresh seed extract showed the highest antiradical activities, with IC50 values of 2.88 and 3.44 µg/mL in the DPPH● and ABTS●+ assays, respectively. On the other hand, the extracts (2 to 8 mg/mL) inhibited Escherichia coli, with the dehydrated peel being the most effective treatment. These findings suggest that the use of 70% v/v hydroethanolic extraction and sonication treatment for both fresh and dehydrated samples increased the release of bioactive compounds. Consequently, high antioxidant capacity and antimicrobial activity were detected, so these techniques should be recommended to produce extracts with higher biological activity, which could be used as a food supply and in nutraceutical products.