scholarly journals Impact of Cold versus Hot Brewing on the Phenolic Profile and Antioxidant Capacity of Rooibos (Aspalathus linearis) Herbal Tea

Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 499 ◽  
Author(s):  
Elisabetta Damiani ◽  
Patricia Carloni ◽  
Gabriele Rocchetti ◽  
Biancamaria Senizza ◽  
Luca Tiano ◽  
...  

Consumption of rooibos (Aspalathus linearis) as herbal tea is growing in popularity worldwide and its health-promoting attributes are mainly ascribed to its phenolic composition, which may be affected by the brewing conditions used. An aspect so far overlooked is the impact of cold brewing vs regular brewing and microwave boiling on the (poly) phenolic profile and in vitro antioxidant capacity of infusions prepared from red (‘fermented’, oxidized) and green (‘unfermented’, unoxidized) rooibos, the purpose of the present study. By using an untargeted metabolomics-based approach (UHPLC-QTOF mass spectrometry), 187 phenolic compounds were putatively annotated in both rooibos types, with flavonoids, tyrosols, and phenolic acids the most represented type of phenolic classes. Multivariate statistics (OPLS-DA) highlighted the phenolic classes most affected by the brewing conditions. Similar antioxidant capacities (ORAC and ABTS assays) were observed between cold- and regular-brewed green rooibos and boiled-brewed red rooibos. However, boiling green and red rooibos delivered infusions with the highest antioxidant capacities and total polyphenol content. The polyphenol content strongly correlated with the in vitro antioxidant capacities, especially for flavonoids and phenolic acids. These results contribute to a better understanding of the impact of the preparation method on the potential health benefits of rooibos tea.

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Esteban Villamil-Galindo ◽  
Franco Van de Velde ◽  
Andrea M. Piagentini

AbstractThe post-harvest processing of strawberries generates considerable amounts of by-products that consist of the inedible parts of the fruit (sepal, calyx, stem, and non-marketable portion of the fruit), which is an environmental problem for local producers and industries. This study aimed to revalue these kinds of tissues through identifying and quantifying the genotype influence on the total phenolic content, phenolic profile, and the antioxidant activity of the by-products from three strawberry cultivars: ‘Festival’ (FE), ‘San Andreas ‘ (SA), and ‘Camino Real’ (CR). The total phenolic content was determined by the Folin–Ciocalteu method, in-vitro antioxidant activity by the DPPH* radical scavenging method and the phenolic profile by PAD–HPLC. The different genotypes showed significant differences (p < 0.05) in total phenolic content (TPC), FE being the one with the highest TPC (14.97 g of gallic acid equivalents < GAE > /Kg of by-product < R >), followed by SA and CR cultivars. The antioxidant capacity of the SA and FE tissues were similar (p > 0.05) and higher (15.1–16.3 mmol Trolox equivalents < TE > /Kg R) than CR. Eight main phenolic compounds were identified and quantified on the three cultivars. Agrimoniin was the principal polyphenol (0.38–1.56 g/Kg R), and the cultivar FE had the highest concentration. This compound showed the highest correlation coefficient with the antioxidant capacity (R2 0.87; p < 0.001). This study highlighted the impact of the multi-cultivar systems in strawberry production on the bioactive potential and the diversity of secondary metabolites obtained from strawberry agro-industrial by-products at a low cost.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 554
Author(s):  
Marta C. Coelho ◽  
Tânia B. Ribeiro ◽  
Carla Oliveira ◽  
Patricia Batista ◽  
Pedro Castro ◽  
...  

In times of pandemic and when sustainability is in vogue, the use of byproducts, such as fiber-rich tomato byproducts, can be an asset. There are still no studies on the impact of extraction methodologies and the gastrointestinal tract action on bioactive properties. Thus, this study used a solid fraction obtained after the conventional method (SFCONV) and a solid fraction after the ohmic method (SFOH) to analyze the effect of the gastrointestinal tract on bioactive compounds (BC) and bioactivities. Results showed that the SFOH presents higher total fiber than SFCONV samples, 62.47 ± 1.24–59.06 ± 0.67 g/100 g DW, respectively. Both flours present high amounts of resistant protein, representing between 11 and 16% of insoluble dietary fiber. Furthermore, concerning the total and bound phenolic compounds, the related antioxidant activity measured by 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay presented significantly higher values for SFCONV than SFOH samples (p < 0.05). The main phenolic compounds identified in the two flours were gallic acid, rutin, and p-coumaric acid, and carotenoids were lycopene, phytofluene, and lutein, all known as health promoters. Despite the higher initial values of SFCONV polyphenols and carotenoids, these BCs’ OH flours were more bioaccessible and presented more antioxidant capacity than SFCONV flours, throughout the simulated gastrointestinal tract. These results confirm the potential of ohmic heating to modify the bioaccessibility of tomato BC, enhancing their concentrations and improving their antioxidant capacity.


Author(s):  
Julian Alfke ◽  
Uta Kampermann ◽  
Svetlana Kalinina ◽  
Melanie Esselen

AbstractDietary polyphenols like epigallocatechin-3-gallate (EGCG)—which represents the most abundant flavan-3-ol in green tea—are subject of several studies regarding their bioactivity and health-related properties. On many occasions, cell culture or in vitro experiments form the basis of published data. Although the stability of these compounds is observed to be low, many reported effects are directly related to the parent compounds whereas the impact of EGCG degradation and autoxidation products is not yet understood and merely studied. EGCG autoxidation products like its dimers theasinensin A and D, “P2” and oolongtheanin are yet to be characterized in the same extent as their parental polyphenol. However, to investigate the bioactivity of autoxidation products—which would minimize the discrepancy between in vitro and in vivo data—isolation and structure elucidation techniques are urgently needed. In this study, a new protocol to acquire the dimers theasinensin A and D as well as oolongtheanin is depicted, including a variety of spectroscopic and quadrupole time-of-flight high-resolution mass spectrometric (qTOF-HRMS) data to characterize and assign these isolates. Through nuclear magnetic resonance (NMR) spectroscopy, polarimetry, and especially circular dichroism (CD) spectroscopy after enzymatic hydrolysis the complementary atropisomeric stereochemistry of the isolated theasinensins is illuminated and elucidated. Lastly, a direct comparison between the isolated EGCG autoxidation products and the monomer itself is carried out regarding their antioxidant properties featuring Trolox equivalent antioxidant capacity (TEAC) values. These findings help to characterize these products regarding their cellular effects and—which is of special interest in the flavonoid group—their redox properties.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4399
Author(s):  
Norhasnida Zawawi ◽  
Pei Juin Chong ◽  
Nurul Nadhirah Mohd Tom ◽  
Nurkhairina Solehah Saiful Anuar ◽  
Salma Malihah Mohammad ◽  
...  

Honey is a well-known natural sweetener and is rich in natural antioxidants that prevent the occurrence of oxidative stress, which is responsible for many human diseases. Some of the biochemical compounds in honey that contribute to this property are vitamins and phenolic compounds such as phenolic acids and flavonoids. However, the extent to which these molecules contribute towards the antioxidant capacity in vitro is inconsistently reported, especially with the different analytical methods used, as well as other extrinsic factors that influence these molecules’ availability. Therefore, by reviewing recently published works correlating the vitamin, total phenolic, and flavonoid content in honey with its antioxidant activities in vitro, this paper will establish a relationship between these parameters. Based on the literature, vitamins do not contribute to honey’s antioxidant capacity; however, the content of phenolic acids and flavonoids has an impact on honey’s antioxidant activity.


Heliyon ◽  
2020 ◽  
Vol 6 (5) ◽  
pp. e03845 ◽  
Author(s):  
G. Astrid Garzón ◽  
Carlos Y. Soto ◽  
Marcela López-R ◽  
Kenneth M. Riedl ◽  
Cindi R. Browmiller ◽  
...  

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 488
Author(s):  
Agnieszka Szopa ◽  
Michał Dziurka ◽  
Sebastian Granica ◽  
Marta Klimek-Szczykutowicz ◽  
Paweł Kubica ◽  
...  

Schisandra rubriflora is a dioecious, underestimated medicinal plant species known from traditional Chinese medicine. The present study was aimed at characterising the polyphenolic profile composition and the related antioxidant capacity of S. rubriflora fruit, stem and leaf and in vitro microshoot culture extracts. Separate analyses of material from female and male specimens were carried out. This study was specifically aimed at detailed characterisation of the contribution of phenolic compounds to overall antioxidant activity using ultra-high-performance liquid chromatography with a photodiode array detector coupled to electrospray ionization ion trap mass spectrometry (UHPLC-DAD-ESI-MS3) and a high-performance liquid chromatography-diode array detector (HPLC-DAD). Using UHPLC-DAD-ESI-MS3, twenty-seven phenolic compounds from among phenolic acids and flavonoids were identified. Concentrations of three phenolic acids (neochlorogenic, chlorogenic and cryptochlorogenic acids) and eight flavonoids (hyperoside, rutoside, isoquercitrin, guaijaverin, trifolin, quercetin, kaempferol, and isorhamnetin) were determined using HPLC-DAD using reference standards. The highest total phenolic content was confirmed for the stem and leaf extracts collected in spring. The contents of phenolic compounds of in vitro biomasses were comparable to that in the fruit extracts. The methanolic extracts from the studied plant materials were evaluated for their antioxidant properties using various in vitro assays, namely free radicals scavenging estimation using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), ferric-reducing antioxidant power (FRAP) and cupric-reducing antioxidant capacity (CUPRAC) as well as QUick, Easy, New, CHEap, and Reproducible CUPRAC (QUENCHER-CUPRAC) assays. A close relationship between the content of polyphenolic compounds in S. rubriflora and their antioxidant potential has been documented.


2011 ◽  
Vol 101 (8) ◽  
pp. 929-934 ◽  
Author(s):  
Nadia Ponts ◽  
Laetitia Pinson-Gadais ◽  
Anne-Laure Boutigny ◽  
Christian Barreau ◽  
Florence Richard-Forget

The impact of five phenolic acids (ferulic, coumaric, caffeic, syringic, and p-hydroxybenzoic acids) on fungal growth and type B trichothecene production by four strains of Fusarium graminearum was investigated. All five phenolic acids inhibited growth but the degree of inhibition varied between strains. Our results suggested that the more lipophilic phenolic acids are, the higher is the effect they have on growth. Toxin accumulation in phenolic acid-supplemented liquid glucose, yeast extract, and peptone cultures was enhanced in the presence of ferulic and coumaric acids but was reduced in the presence of p-hydroxybenzoic acid. This modulation was shown to correlate with a regulation of TRI5 transcription. In this study, addition of phenolic acids with greater antioxidant properties resulted in a higher toxin accumulation, indicating that the modulation of toxin accumulation may be linked to the antioxidant properties of the phenolic acids. These data suggest that, in planta, different compositions in phenolic acids of kernels from various cultivars may reflect different degrees of sensitivity to “mycotoxinogenesis.”


2010 ◽  
Vol 46 (4) ◽  
pp. 651-656 ◽  
Author(s):  
Adriana Bramorski ◽  
Adriana da Rosa Cherem ◽  
Chaiana Paula Marmentini ◽  
Joseane Torresani ◽  
Tatiana Mezadri ◽  
...  

The plant Morinda citrifolia L. (noni) has been the focus of many recent studies due to its potential effects on treatment and prevention of several diseases. However, there are few in vivo and in vitro studies concerning its composition and antioxidant capacity. The aim of the present study was to determine the total polyphenol content (TPC) and antioxidant capacity of a juice commercialized as noni juice, but containing grape, blueberry and noni fruits. Commercial noni juice was compared against its separate constituents of blueberry and grape juice. Folin-Ciocalteu and DPPH• methods were used to determine the concentration of total polyphenol content and antioxidant activity, respectively. Commercial noni juice presented higher values of TPC (91.90 mg of gallic acid/100 mL juice) and antioxidant activity (5.85 mmol/L) compared to its 5% diluted constituents. Concentrated blueberry juice presented higher TPC and antioxidant activity than the other juices analyzed. Considering that the blueberry and grape juices account for only 10% in the composition of commercial noni juice, it can be inferred that these two components contribute significantly to the antioxidant activity. Therefore, additional studies are necessary in order to elucidate the contribution of the noni juice as an antioxidant.


2019 ◽  
Vol 287 ◽  
pp. 258-264 ◽  
Author(s):  
J. Ortega-Vidal ◽  
A. Ruiz-Riaguas ◽  
M.L. Fernández-de Córdova ◽  
P. Ortega-Barrales ◽  
E.J. Llorent-Martínez

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 534 ◽  
Author(s):  
Sotirios Kiokias ◽  
Charalampos Proestos ◽  
Vassiliki Oreopoulou

Nature has generously offered a wide range of herbs (e.g., thyme, oregano, rosemary, sage, mint, basil) rich in many polyphenols and other phenolic compounds with strong antioxidant and biochemical properties. This paper focuses on several natural occurring phenolic acids (caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) and first gives an overview of their most common natural plant sources. A summary of the recently reported antioxidant activities of the phenolic acids in o/w emulsions is also provided as an in vitro lipid-based model system. Exploring the interfacial activity of phenolic acids could help to further elucidate their potential health properties against oxidative stress conditions of biological membranes (such as lipoproteins). Finally, this review reports on the latest literature evidence concerning specific biochemical properties of the examined phenolic acids.


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