scholarly journals Phenols and Melanoidins as Natural Antioxidants in Beer. Structure, Reactivity and Antioxidant Activity

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 400 ◽  
Author(s):  
Alvaro Martinez-Gomez ◽  
Isabel Caballero ◽  
Carlos A. Blanco

Beer is one of the most consumed drinks around the world, containing a variety of compounds that offer both appreciated sensorial characteristics and health advantages. Important healthy compounds in beer are those with antioxidant properties that attenuate the content of free radicals produced as by-products in the human metabolism, exerting an appreciable effect against cancers or cardiovascular diseases. This work details a study of antioxidant compounds present in beer, focusing on the two main groups: phenols (including polyphenolic forms) and melanoidins, formed specifically during brewing as Maillard products. The fundaments of the most important methods to evaluate beer antioxidant activity, the main antioxidant compounds present in beer—especially those with healthy properties—and the new trends to increase beer antioxidant activity are also discussed.

2016 ◽  
Vol 9 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Silvia Mošovská ◽  
Patrícia Petáková ◽  
Michal Kaliňák ◽  
Anna Mikulajová

Abstract The evaluation of antioxidant potential of food has received much attention in recent years. Antioxidant compounds can scavenge free radicals and thereby can protect the human body from free radicals. This study was focused on the isolation of curcuminoids from the dried turmeric rhizome, and studying their antioxidant activity. The presence of curcuminoids was identified in turmeric sample by Nuclear Magnetic Resonance (NMR) analysis. Since neutral curcumin is known to be poorly soluble, the synthesis of curcumin-cyclodextrin and curcumin-phospholipid complexes was also performed. The antioxidant activity of isolated curcuminoids was assessed by two methods (ABTS and FRAP assay) and their scavenging activities were compared with those of prepared complexes. The ability to reduce ABTS radical cation decreased as follows: quercetin > trolox > curcuminoids > curcumin-cyclodextrin complex > curcumin-phospholipid complex. The reducing potential of tested samples in descending order was quercetin > trolox > curcumin-cyclodextrin complex > curcuminoids > curcumin-phospholipid complex.


Author(s):  
Anna Pachuta-Stec

: The information about the presence of free radicals in biological materials was given for the first time about 70 years ago. Since then, numerous scientific studies have been conducted and the science of free radicals was born. Today we know that free radicals are by-products of enzymatic reactions occurring in the organism. They are produced during endogenous processes such as: cell respiration, phagocytosis, biosynthesis, catalysis, and biotransformation. They can also be produced by exogenous processes (radiation, sunlight, heavy metals, bacteria, fungi, protozoa and viruses). The overproduction of free radicals affects the aging processes, oxidative stress (OS) and takes part in the pathogenesis of various diseases. Among them are cancer, rheumatoid arthritis, neurodegenerative diseases: Alzheimer and Parkinson, pulmonary diseases, atherosclerosis and DNA damage. Compounds with antioxidant activity are very important nowadays because they allow organisms to keep a balance between the production of free radicals and the speed of their neutralization in the body. Next to the natural antioxidants (flavonoids, carotenoids, vitamins, etc.), synthetic ones are also of great importance. Among synthetic compounds with antioxidant activity are 1,2,4-triazoles and its derivatives. 1,2,4-Triazoles are heterocyclic compounds with three nitrogen atoms. Due to a broad spectrum of biological activities, these derivatives have been of interest to scientists for many years. Some of them are also used as drugs. The finding of new synthetic compounds with antioxidant features in the triazole group has become important problem of medicinal chemistry.


Author(s):  
Tomasz Piechowiak ◽  
Bartosz Skóra ◽  
Katarzyna Grzelak-Błaszczyk ◽  
Michał Sójka

AbstractThe purpose of this study was to investigate the biological properties of an extract obtained from the waste of blueberry fruit. The study covered the optimization of extraction of antioxidants from blueberry pomace and the determination of antioxidant properties of the extract using HaCaT as the model organism. Research showed that the yield of antioxidants extraction from blueberry waste was dependent on the applied extraction conditions. Based on the mathematical models, the optimal conditions of extraction process in which the maximum quantity of antioxidant compounds is achieved from the waste mass unit, i.e., the relation of the waste mass to the volume of ethanol equal to 1:17.36, and process time equal to 1000 s. The obtained extract was characterized by high antioxidant activity, which was shaped by high content of polyphenols, mainly anthocyanins. Moreover, the extract showed a high ability to protect HaCaT cells from the occurrence of oxidative stress induced by H2O2. Cells treated with the extract and H2O2 generated a lower amount of ROS than cells treated with H2O2 only. The obtained results will be base of further studies on applying the extract in production of diet supplements and functional foods with increased antioxidant activity. Moreover, the main research material is blueberry pomace which is a troublesome waste material for juice producers. Consequently, according to a sustainable development idea, the study results will provide an opportunity to increase interest in the problem of rational use of the waste material to a certain extent.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4518
Author(s):  
Raquel Sousa ◽  
Artur Figueirinha ◽  
Maria Teresa Batista ◽  
Maria Eugénia Pina

Cymbopogon citratus DC (Stapf.) is a perennial grass and it is distributed around the world. It is used as a condiment for food and beverage flavouring in the form of infusions and decoctions of its dried leaves. Our previous studies have shown antioxidant, anti-inflammatory and gastroprotective activities for the infusion and its phenolic fractions. The aim of the present work was to develop oral dosage forms from a Cymbopogon citratus extract to be used as a functional food with antioxidant properties. Initially, an essential oil-free infusion was prepared, lyophilized and characterized by HPLC-PDA. Total phenols were quantified with the Folin–Ciocalteu method and the antioxidant activity was assessed by DPPH assay. Gelatine capsules containing the extract with different excipients, selected after DSC and IR trials, were prepared. A formulation exhibiting better antioxidant behaviour in a gastric environment was attained. These results suggest that the proposed formulation for this extract could be a valuable antioxidant product and, consequently, make an important contribution to “preventing” and minimizing diseases related to oxidative stress conditions.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 165
Author(s):  
Elisabetta Bravi ◽  
Giovanni De Francesco ◽  
Valeria Sileoni ◽  
Giuseppe Perretti ◽  
Fernanda Galgano ◽  
...  

The brewing industry produces high quantities of solid and liquid waste, causing disposal issues. Brewing spent grains (BSGs) and brewing spent hop (BSH) are important by-products of the brewing industry and possess a high-value chemical composition. In this study, BSG and BSH, obtained from the production process of two different types of ale beer (Imperial red and Belgian strong beer) were characterized in terms of valuable components, including proteins, carbohydrates, fat, dietary fiber, β-glucans, arabinoxylans, polyphenols, and phenolic acids, and antioxidant activity (Ferric Reducing Antioxidant Power Assay (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)). Significant concentrations of total polyphenols were observed in both BSH and BSG samples (average of about 10 mg GAE/g of dry mass); however, about 1.5-fold higher levels were detected in by-products of Belgian strong ale beer compared with Imperial red. Free and bound phenolic acids were quantified using a validated chromatographic method. A much higher level of total phenolic acids (TPA) (about 16-fold higher) was found in BSG samples compared with BSHs. Finally, their antioxidant potential was verified. By-products of Belgian strong ale beer, both BSG and BSH, showed significantly higher antioxidative capacity (about 1.5-fold lower inhibitory concentration (IC50) values) compared with spent grains and hop from the brewing of Imperial red ale. In summary, BSG and BSH may be considered rich sources of protein, carbohydrates, fiber, and antioxidant compounds (polyphenols), and have the potential to be upcycled by transformation into value-added products.


2021 ◽  
Vol 19 (1) ◽  
pp. 113-123
Author(s):  
PK Dash ◽  
S Das ◽  
MA Mannan ◽  
M Jahan

Determination of antioxidant activity is one of the key elements for understanding the biological properties of a widely used spice onion (A. cepa). In contrast, physical properties help understand the textural quality of onion necessary for postharvest operations of sorting and grading in particular. Considering the physicochemical importance of onion, the present study focused on the determination of physical attributes and antioxidant content of the onion germplasm in Bangladesh using visual methods and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The five-onion germplasms (BARI Piaz-2, BARI Piaz-3, BARI Piaz-4, BARI Piaz-5, Faridpuri Vati) collected from selected onion growers of the Department of Agricultural Extension (DAE) of the southwestern part of Bangladesh were used as treatments for physicochemical analysis at the Horticulture laboratory of the Agrotechnology Discipline, Khulna University, Khulna, Bangladesh during the period from February to August 2019. The laboratory study was laid out in Completely Randomized Design (CRD) with three replications. Most of the physical characteristics of onion were highest in germplasm-1 than those of the other germplasm tested. The results showed that the DPPH free radicals were scavenged by all onion germplasm extracts in a concentration-dependent pattern. The highest IC50 value (238.10 ppm) was noticed in germplasm-3 and the lowest in germplasm-5 (161.29 ppm) with no statistical difference from germplasm-4 (172.41 ppm). The lower IC50 value indicating that onion germplasms-5 and -4 extracts were more potent in scavenging free radicals than the other onion germplasms. Thus, the low IC50 value facilitated the germplasm-5 and -4 to be enriched with antioxidant compounds significantly in higher amounts than the others. SAARC J. Agric., 19(1): 113-123 (2021)


Author(s):  
Pozdnyakovа Т.А. ◽  
Kuleshovа Е.S. ◽  
Bubenchikov R.A.

The predominance of synthetic and genetically modified foods in the diet of a modern person often leads to disruption of natural metabolic processes and the accumulation of toxic free radicals in the body, which provokes the development of various diseases. Natural antioxidants from medicinal plants can help maintain health and stop the processes of peroxidation. In our opinion, Аstragalus onobrychis can become a promising source of natural antioxidants. The aim of this study was to establish the antioxidant activity in extracts from the herb Astragalus onobrychis. In order to obtain objective and reliable results during our research, we used two methods: the method of titrimetry and spectrophotometry of free radicals. The titrimetric method is based on the chemical interaction between an oxidizing agent (potassium permanganate) and natural antioxidants present in extracts from plant raw materials, since they exhibit the properties of reducing agents. The spectrophotometric method makes it possible to assess the value of antioxidant activity and the duration of the reaction by assessing the interaction of 2,2-diphenyl-1-picrylhydrazil with plant antioxidants. To establish the relationship between the antioxidant activity and the presence of phenolic compounds in the plant, the content of flavonoids and hydroxycinnamic acids in the herb Astragalus onobrychis was determined. As a result of the studies, the total antioxidant activity of extracts from the herb Astragalus onobrychis was established and it was revealed that its value depends on the type of extractant used, since this factor is associated with the content of various groups of natural antioxidants in the extraction. The data obtained indicate the prospects of using the herb Astragalus onobrychis as a source of natural antioxidants.


2019 ◽  
Vol 9 (3) ◽  
pp. 80-86
Author(s):  
Hanane Megdad ◽  
Samuel Chiomokhare ◽  
Ahmed M’Hamedi ◽  
Paul L Chazot

Plant natural products have a long history of being a rich source of neuroactive drugs.The total phenolic and flavonoid content, and antioxidant activity of ethanol, chloroform and aqueous extracts of AlgerianMedicagoSativaL, leaves were measured to discover new potential sources of Algerian natural antioxidants and neuroactives. All extracts were non-neurotoxic up to 1 mg/ ml for 24 h exposure. The total phenolcontent of M.Sativa extracts ranged between 38 and 69 mg GAE per g extracts. All of the extracts displayed antioxidant capacityassessed by two methods, but at different levels depending on the concentration and the extraction solvent used. The overall antioxidant potency was in the order water > chloroform> ethanol extracts, and the phenolic content exhibited a positive correlation with the antioxidant activity of M. Sativa extracts.Despite a weaker antioxidant activity, the ethanol extract elicited a calcium spike and suppressed the KCl-induced depolarisation response in neurons, indicating effect on ligand-and/or voltage gated calcium channels. In contrast, the chloroform and water extractsdisplayed no apparent direct functional effects. In conclusion, the antioxidant and functional properties related to phenolic content of Algerian Medicago Sativa L. in water and ethanol extracts, respectively.


Marine Drugs ◽  
2021 ◽  
Vol 19 (10) ◽  
pp. 549
Author(s):  
Noémie Coulombier ◽  
Thierry Jauffrais ◽  
Nicolas Lebouvier

The demand for natural products isolated from microalgae has increased over the last decade and has drawn the attention from the food, cosmetic and nutraceutical industries. Among these natural products, the demand for natural antioxidants as an alternative to synthetic antioxidants has increased. In addition, microalgae combine several advantages for the development of biotechnological applications: high biodiversity, photosynthetic yield, growth, productivity and a metabolic plasticity that can be orientated using culture conditions. Regarding the wide diversity of antioxidant compounds and mode of action combined with the diversity of reactive oxygen species (ROS), this review covers a brief presentation of antioxidant molecules with their role and mode of action, to summarize and evaluate common and recent assays used to assess antioxidant activity of microalgae. The aim is to improve our ability to choose the right assay to assess microalgae antioxidant activity regarding the antioxidant molecules studied.


2020 ◽  
Vol 11 (1) ◽  
pp. 1-27
Author(s):  
Adil Hussain

Background: There exist natural antioxidants in plants that scavenge harmful free radicals from the body. Free radicals are species of chemical origin with an unpaired electron and play a pivotal role in combating against health-related problems like lung damage, inflammation, and cardiovascular ailments etc. Antioxidants halt the development of these free radicals called the reactive oxygen species either by chelating the trace elements or by enzymes inhibition. Objectives: The aim of present review was to collect information about Pakistani medicinally important plants with the exploration of their antioxidant potential. Methodology: Total 206 papers were looked over, which were obtained from numerous sources like; Google Scholar, Medline, PubMed, Research Gate, Science Direct, Scopus and Web of Science. Results: Overall, 93 plants representing 44 families with potential antioxidant activity reported from Pakistan have been presented in this review. Maximum number of species from Asteracea, Poaceae and Rutaceae familes were scrutinized for their potential antioxidant activity from Pakistan. Conclusion: The present review clearly designates that the presence of phytochemicals and antioxidant activity of medicinal plants from Pakistan vary with the species of the plants and material/extracts used. From this review, it is recommended to perform comprehensive experimental investigations based on toxicology and ethnopharmacology on these precious plants from Pakistan. It will be advantageous in the provision of trustworthy information to patients and determine further innovative compounds for safer and new drugs development with fewer side effects.


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