The antioxidant potential of flesh, albedo and flavedo extracts from different varieties of grapefruits

Abstract

Background. The supplementation of antioxidants, in particular those of plant origin, may help to prevent the development of diseases caused by oxidative stress. Therefore, it is important to study plants for their antioxidant contents. Up to now, only a few reports on the antioxidant activity of different varieties and parts of grapefruit have been published. Therefore, the aim of this study was to evaluate the antioxidant potential of different parts and varieties of grapefruit. Moreover, the impact of different extraction parameters on the activity of the obtained extracts was estimated. Materials and methods. Extracts of albedo, flavedo and flesh from three varieties of grapefruit-red, white and sweetie-were obtained using ultrasound-assisted extraction (time-5, 10, 15 and 30 minutes; solventsdistilled water as well as 20, 40, 70 and 96% (v/v) ethanol). The samples were evaluated using the DPPH, ABTS, FRAP and Folin-Ciocalteu methods. Results. The extracts of peel (in particular, those of albedo) showed higher antioxidant potential than the samples of flesh. In the majority of cases, the highest potential in the group of flesh and flavedo extracts was observed in the sweetie samples. The highest activity in the group of albedo samples was found in the white grapefruit extracts. Parameters such as the type of solvent and the extraction time had an impact on the antioxidant activity of the obtained extracts. Conclusion. Grapefruit, in particular their peels, could be valuable sources of natural antioxidants. However, more detailed studies on the antioxidant properties of the studied plants are required.

The Effect of Brewing Process Parameters on Antioxidant Activity and Caffeine Content in Infusions of Roasted and Unroasted Arabica Coffee Beans Originated from Different Countries

“…Moreover, the ability of samples to reduce ferric and cupric ions was evaluated using FRAP (ferric reducing antioxidant power), PFRAP (potassium ferricyanide reducing power), and CUPRAC (cupric ion reducing antioxidant capacity) methods. The evaluation of antioxidant activity by DPPH, ABTS, and FRAP methods was performed as described by Muzykiewicz et al [ 47 ]. To evaluate ferric reducing capacity of infusions, the FRAP method, as described by Apak et al [ 48 ], and the PFRAP technique (with slight modifications), according to Jayaprakasha et al [ 49 ], were used.…”

“…The total polyphenols content (Folin–Ciocalteu method) was evaluated as described by Muzykiewicz et al [ 47 ], whereas the flavonoids according to Saeed et al [ 50 ]. The spectrophotometric measurements were performed in 1 cm cuvettes using Hitachi U-5100 spectrophotometer (Japan).…”

Antioxidant activity and polyphenol content in extracts from various parts of fresh and frozen mangosteen

“…Evaluation of the DPPH, FRAP, ABTS and F-C methods was performed as described by Muzykiewicz et al (2019). In the case of fresh peel and flesh, the results were calculated and expressed as mg of reference substance/g fresh material, whereas for frozen, they were calculated as mg of reference substance/g frozen material.…”

Antioxidant activity of various plant sprouts extracts depending on the processing method of plant material – an in vitro study

“…To evaluate the antioxidant activity of extracts, the DPPH, ABTS, FRAP methods were used, as described by Muzykiewicz et al [6]. The total polyphenols content, determined by Folin-Ciocalteu (F-C) method, was also carried out as previously described by Muzykiewicz et al [6].…”

“…To evaluate the antioxidant activity of extracts, the DPPH, ABTS, FRAP methods were used, as described by Muzykiewicz et al [6]. The total polyphenols content, determined by Folin-Ciocalteu (F-C) method, was also carried out as previously described by Muzykiewicz et al [6]. The cupric reducing antioxidant capacity (CUPRAC) was performed Key words: sprouts, antioxidant activity, ultrasound-assisted extraction, food processing methods Słowa kluczowe: kiełki, aktywność antyoksydacyjna, ekstrakcja wspomagana ultradźwiękami, metody przetwarzania żywności according to the procedure described by Apak et al [7].…”