Antibacterial and antioxidant activity of pulp, peel and leaves of Feijoa sellowiana: Effect of extraction techniques, solvents and concentration

Abstract

The present study evaluated the effect of extraction techniques (ultrasound-assisted extraction (U) and shaking water bath extrac-tion (WB)), solvents (etha-nol, acetone and distilled water) and concentration (2.5% and 5%) on total phe-nolic content (TPC), anti-bacterial and antioxidant activities of extracts ob-tained from feijoa leaves, peel and pulp. The antibac-terial activity of feijoa ex-tracts were tested in vitro against 6 pathogens bacteria by the disc diffusion method and the antioxidant activity was evaluated by 2,2 diphe-nyl-1-picrylhydrazyl radical assay. The results indicated that leaves and peel extracts exhibited stronger antibac-terial activity than that of pulp. In generally, WB-A5%, WB-W5%, U-A5% and U-W 5% extracted with acetone (A) and water (W) at 5% concentration from feijoa leaves, peel and pulp showed more antibacterial activity against all tested pathogen bacteria. The leaves, peel, and pulp ex-tracts had high antioxidant activity with 85.78-90.82%, 89.86-91.60%, and 81.49-91.31%, respectively. Peel extracts had slightly higher antioxidant activity than leaves and pulp extracts. TPC of leaves, peel, and pulp extracts were in the range of 488.99-554.00, 349.17-517, and 115.64-345.46 mg gallic acid equivalents (GAE)/100 g of extract. The overall findings suggested that different part of feijoa (especially leaves and peel) could be used as a natural antibacterial and an-tioxidant for functional foods.

Usnea antarctica (James Ross Island, Antarctica) and Usnea subfloridana (Uludağ, Turkey) Incorporated Hybrid Nanoflowers with Their Intrinsic Catalytic and Antimicrobial Activities

“…The quantity of phenolic content in each lichen samples was calculated by using reported method. In general, the redox characteristics of phenolic chemicals found in plants allow them to serve as antioxidants [38,39] . The results in Figure 2a and 2b showed no 3 sample (methanolic extract of U. Antarctica ) has the highest TPC activities (230.12 mg GAE/g) among other extracts.…”

Parazoanthus axinellae Extract Incorporated Hybrid Nanostructure and Its Potential Antimicrobial Activity**

“…The approach of antimicrobial act of plant extracts altered on the type of bacteria relating to the cell wall structure. [48] According to the results of antibacterial susceptibility tests, the hybrid nanoflowers had capable antimicrobial affects comparing with the extract of P. axinellae. As amphipathic hybrid nanomaterials, NFs can exhibit antibacterial activity by adhering to the outer membrane of Grampositive and Gram-negative bacteria.…”

“…Stock cultures were subcultured onto Mueller Hinton Agar (MHA) at 37 °C for 24 h. Then, all bacterial strains were adjusted to 0.5 McFarland standard turbidity (1×10 8 CFU/mL) for antimicrobial evaluation. [48] Each experiment was carried out in triplicate. CuSO 4 • 3H 2 O and other chemicals were from Sigma-Aldrich.…”

Determination of Antimicrobial and Antioxidant Activities of Wastes (Tea Seed, Orange, and Mandarin Peel) of Some Local Product Grown in Rize Province

“…Bu amaçla daha önceden 0,05 mg/mL (%5), 0,10 mg/mL (%10) ve 0,25 mg/mL (%25) oranlarında hazırlanan ekstrelerden 15'er µl alınarak steril boş antibiyotik disklere (6 mm) emdirildi ve bakteri inoküle edilen MHA içeren besiyeri üzerine yerleştirildi. Daha sonra antimikrobiyal etki gösteren ekstrelerin oluşturdukları inhibasyon zon çapları kumpas (MarCal 16 ER, Germany) ile ölçüldü (Karslı, 2021).…”