scholarly journals Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

2021 ◽  
Vol 20 (3) ◽  
pp. 379-389
Author(s):  
J. Tienaho ◽  
N. Silvan ◽  
R. Muilu-Mäkelä ◽  
P. Kilpeläinen ◽  
E. Poikulainen ◽  
...  

AbstractBryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species.

2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


2017 ◽  
Vol 39 (1) ◽  
pp. 103 ◽  
Author(s):  
Luciana Ercoli ◽  
Érica Oliveira Barizão ◽  
Joana Shuelter Boeing ◽  
Marcus Vinícius Kvitschal ◽  
Jesuí Vergilio Visentainer ◽  
...  

In this research, the total phenolic content (TPC) and antioxidant capacity (FRAP and DPPH•× assays) of pulps and peels of advanced selection of apples grown in Brazil were investigated. The correlation analyses between the activity of polyphenoloxidase enzyme (PPO), vitamin C content, total titratable acidity, and color parameters were performed. The results indicated that the data differed significantly among the apple genotypes studied. The peels of the selection Epagri 170-91 and Epagri 170-25 showed the highest TPC and antioxidant capacities. In addition, the pulps of the Epagri 170-91 presented the highest TPC and antioxidant capacities, the lowest enzymatic browning, highest amount of vitamin C and lowest enzymatic activity when compared with other genotypes. The TPC and antioxidant capacities were significantly correlated in all genotypes analyzed. High correlation values between enzymatic browning and factors that affect the apple color were also found in all analyzed pulps, except between enzymatic browning and TPC. The results demonstrated that the enzymatic browning and TPC, as well as the antioxidant capacity and chemical characteristics, vary considerably depending on the apple genotypes and fruit tissues analyzed. 


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Sofia C. Lourenço ◽  
Débora A. Campos ◽  
Ricardo Gómez-García ◽  
Manuela Pintado ◽  
M. Conceição Oliveira ◽  
...  

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 234 ◽  
Author(s):  
Yili Hong ◽  
Zening Wang ◽  
Colin J. Barrow ◽  
Frank R. Dunshea ◽  
Hafiz A. R. Suleria

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries.


Foods ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 281 ◽  
Author(s):  
Saleha Akter ◽  
Michael E. Netzel ◽  
Ujang Tinggi ◽  
Simone A. Osborne ◽  
Mary T. Fletcher ◽  
...  

Terminalia ferdinandiana (Kakadu plum) is a native Australian plant containing phytochemicals with antioxidant capacity. In the search for alternatives to synthetic preservatives, antioxidants from plants and herbs are increasingly being investigated for the preservation of food. In this study, extracts were prepared from Terminalia ferdinandiana fruit, leaves, seedcoats, and bark using different solvents. Hydrolysable and condensed tannin contents in the extracts were determined, as well as antioxidant capacity, by measuring the total phenolic content (TPC) and free radical scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Total phenolic content was higher in the fruits and barks with methanol extracts, containing the highest TPC, hydrolysable tannins, and DPPH-free radical scavenging capacity (12.2 ± 2.8 g/100 g dry weight (DW), 55 ± 2 mg/100 g DW, and 93% respectively). Saponins and condensed tannins were highest in bark extracts (7.0 ± 0.2 and 6.5 ± 0.7 g/100 g DW). The antimicrobial activity of extracts from fruit and leaves showed larger zones of inhibition, compared to seedcoats and barks, against the foodborne bacteria Listeria monocytogenes, Bacillus cereus, Methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa. The minimum inhibitory concentration and minimum bactericidal concentration in response to the different extracts ranged from 1.0 to 3.0 mg/mL. Scanning electron microscopy images of the treated bacteria showed morphological changes, leading to cell death. These results suggest that antioxidant rich extracts of Terminalia ferdinandiana fruits and leaves have potential applications as natural antimicrobials in food preservation.


2014 ◽  
Vol 12 (8) ◽  
pp. 858-867 ◽  
Author(s):  
Christina Zălaru ◽  
Claudia Crişan ◽  
Ioan Călinescu ◽  
Zenovia Moldovan ◽  
Isabela Ţârcomnicu ◽  
...  

AbstractThe aim of this research was to investigate the chemical composition of Coreopsis tinctoria Nutt. fruits extract, to highlight the potential of ultrasound assisted extraction in the fast preparation of extracts rich in polyphenols using different solvents (55%, 78% and 96% hydrous ethanol) and to evaluate the antioxidant potential of formulated extracts. LC-MS/MS was used to characterize the ethanolic extract from Coreopsis tinctoria Nutt. dried fruits. The extract contains different flavonoids (marein, flavanomarein, quercetagetin-7-O-glucoside, okanin aurone, leptosidin, luteolin, apigenin) and phenolic acids (chlorogenic acid, caffeic acid). Several parameters that could affect extraction efficiency were evaluated. Finally, this study focused on determination of plant extracts total phenolic content and their antioxidant capacity. The experimental results allowed the selection of the optimum operating parameters leading to the highest total polyphenolic content, expressed as gallic acid equivalents, and avoiding the degradation of phenolic compounds (ethanol 55%; extraction temperature 323.15 K, extraction time 30 min, liquid/solid ratio 20/1). A good relationship between total phenolic content and antioxidant capacity was obtained.


Antioxidants ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 184 ◽  
Author(s):  
Fatiha Brahmi ◽  
Thomas Nury ◽  
Meryam Debbabi ◽  
Samia Hadj-Ahmed ◽  
Amira Zarrouk ◽  
...  

The present study consisted in evaluating the antioxidant, anti-inflammatory and cytoprotective properties of ethanolic extracts from three mint species (Mentha spicata L. (MS), Mentha pulegium L. (MP) and Mentha rotundifolia (L.) Huds (MR)) with biochemical methods on murine RAW 264.7 macrophages (a transformed macrophage cell line isolated from ascites of BALB/c mice infected by the Abelson leukemia virus). The total phenolic, flavonoid and carotenoid contents were determined with spectrophotometric methods. The antioxidant activities were quantified with the Kit Radicaux Libres (KRLTM), the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The MS extract showed the highest total phenolic content, and the highest antioxidant capacity, while the MR extract showed the lowest total phenolic content and the lowest antioxidant capacity. The cytoprotective and anti-inflammatory activities of the extracts were quantified on murine RAW 264.7 macrophages treated with 7-ketocholesterol (7KC; 20 µg/mL: 50 µM) associated or not for 24 h and 48 h with ethanolic mint extracts used at different concentrations (25, 50, 100, 200 and 400 µg/mL). Under treatment with 7KC, an important inhibition of cell growth was revealed with the crystal violet test. This side effect was strongly attenuated in a dose dependent manner with the different ethanolic mint extracts, mainly at 48 h. The most important cytoprotective effect was observed with the MS extract. In addition, the effects of ethanolic mint extracts on cytokine secretion (Interleukin (IL)-6, IL-10, Monocyte Chemoattractant Protein (MCP)-1, Interferon (IFN)-ϒ, Tumor necrosis factor (TNF)-α) were determined at 24 h on lipopolysaccharide (LPS, 0.2 µg/mL)-, 7KC (20 µg/mL)- and (7KC + LPS)-treated RAW 264.7 cells. Complex effects of mint extracts were observed on cytokine secretion. However, comparatively to LPS-treated cells, all the extracts strongly reduce IL-6 secretion and two of them (MP and MR) also decrease MCP-1 and TNF-α secretion. However, no anti-inflammatory effects were observed on 7KC- and (7KC + LPS)-treated cells. Altogether, these data bring new evidences on the potential benefits (especially antioxidant and cytoprotective properties) of Algerian mint on human health.


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