Variation of the Polyphenolic Composition and Antioxidant Capacity of Freshly Prepared Pomegranate Leaf Infusions over One-Day Storage

Abstract

In recent decades, an intensive search for natural and novel types of antioxidant polyphenolics has been carried out on numerous plant materials. However, the current literature has very little information on their storage stability in the form of freshly prepared infusions. This study aims to characterize the polyphenolic composition and the antioxidant capacity of pomegranate (Punica granatum L.) leaf infusions over one-day storage (analyzed at 0, 2, 4, 6, 8, and 24 h). Spectrophotometric evaluation demonstrated that the infusion presented no significant changes in the content of total phenols (131.40–133.47 mg gallic acid g−1) and ortho-diphenols (239.91–244.25 mg gallic acid g−1). The infusion also maintained high stability (over 98% and 82%, respectively) for flavonoids (53.30–55.84 mg rutin g−1) and condensed tannins (102.15–124.20 mg epicatechin g−1), with stable (>90%) potent antioxidant capacity (1.5–2.2 mmol Trolox g−1) throughout 0–24 h storage. The main decrease was observed during 0–2 h storage of flavonoids, 8–24 h storage of tannins, and 0–4 h storage of antioxidant capacity. Chromatographic analysis further revealed that 7 decreased and 11 increased compounds were found within 0–24 h storage. The good stability of the total polyphenolics and antioxidant properties might be related to the complex conversion and activity compensation among these compounds. The findings suggest that pomegranate leaf infusion could be of great interest in the valorization of high added-value by-products and in the application of green and functional alternatives in the food-pharma and nutraceutical industries.

Prunus lusitanica L. Fruits as a Novel Source of Bioactive Compounds with Antioxidant Potential: Exploring the Unknown

“…Three different spectrophotometric methods were used to characterize the antioxidant capacity of the extracts: ABTS and DPPH radical scavenging methods and FRAP (ferric reducing antioxidant power). The DPPH- and ABTS-based determinations were performed as described by Lemos et al [ 24 ], and FRAP was carried out as reported by Yu et al [ 25 ]. Similar to what was performed in the quantification of the different phenolic classes, the three antioxidant assays were carried out on a microscale using 96-well microplates (PrimeSurface MS- 9096MZ, Frilabo, Maia, Portugal) and microplate readers (Multiskan GO Microplate Photometer, Thermo Fisher Scientific, Vantaa, Finland).…”

Antioxidant, Antibacterial, and Cosmeceutical Potential of Four Common Edible Mushrooms

“…The antioxidant activity of sample extracts was determined using 2,2 -azino-bis(3ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH), and ferric-reducing antioxidant power (FRAP) spectrophotometric methods, as reported by Yu et al [27], with some modifications.…”

Comparative evaluation of in vitro antioxidant potential of Punica granatum L. leaves extracts

“…The study by Lamiae et al, 2021 reported that pomegranate peel extract was 283.86 mg GAE/g dw and 185.37 mg QE/g dw polyphenols and flavonoids respectively, while aril extract of pomegranate was polyphenols and flavonoids 166.90 mg GAE/g dw and 57.43 mg QE/g dw respectively. The studies showed that leaves infusion of pomegranate reported that tannins, flavonoids and total phenols contents were 24.20 mg EC/g DW, 55.84 mg RU/g DW and 133.47 mg/g Gallic acid equivalent respectively (Yu et al, 2021). Peels and seeds of pomegranate extracts were higher in total phenolics (0.16-0.73 mg GAE/mg extract) from conventional extraction, while higher contents of total flavonoids (0.019-0.068 mg CATE/mg extract) obtained from sonication-assisted extraction (Campos et al, 2022).…”

“…Its ointment or paste is applied as a treatment for skin injuries and arthritis. The infusion or decoction has been utilized to care for stomach disorders, urinary tract infection, and to treat sore throat and renal colic (Yu et al, 2021). Current research on products of Punica granatum has considerably augmented and profitably drained customers' concentration to medicinal and nutritional values, growing the pomegranate industry's expansion globally.…”