Antioxidant Capacity Of Beverages Research Articles

Enriching alginate matrix used for probiotic encapsulation with whey protein concentrate or its trypsin-derived hydrolysate: Impact on antioxidant capacity and stability of fermented whey-based beverages

The present research is part of an effort to create whey-based functional food. Previously, it was concluded that proteins and peptides in an encapsulation matrix contribute to mechanical properties of beads, fermentative activity, acid and bile tolerance, and the survival of probiotics during the simulated gastrointestinal condition. This research evaluates the effects of using whey protein concentrate and trypsin hydrolysate as components of a matrix for probiotic encapsulation on the antioxidant capacity of a beverage. Carrier with hydrolysate showed better encapsulation efficiency, spherical factor, and antioxidant capacity before and after fermentation compared to the carrier with non-hydrolyzed proteins. Hydrolysis of protein used for carrier formulation positively impacts the beverage’s antioxidant properties and probiotic viability during 28 days of storage. Using proteins, especially peptides, as a matrix component achieved three objectives: protection of probiotics, enrichment of products with antioxidants, and neutralization of possible bitter taste (because the bitter tasting peptides are incorporated into the matrix and as such cannot contribute to the taste of the product) that bioactive peptides usually possess.

Alcoholic beverages from araçá-boi fruit: quantification of antioxidant compounds by NMR ERETIC2

Fermentation is a preservation process responsible for increasing food product shelf life. In this context, alcoholic fermentation can add value to unconventional Amazon fruits, e.g., araçá-boi (Eugenia stipitata). This fruit has various antioxidant phenolic compounds with well-known nutraceutical properties. However, araçá-boi is still underexplored by food industry. This rationale led to investigate the influence of five commercial yeasts (Saccharomyces cerevisiae) and filtration process on chemical composition and antioxidant capacity of araçá-boi beverages. DPPH and Folin Ciocalteu assays were used to determine antioxidant capacity and total phenolic content. Organic compounds' contents were assessed by NMR-ERETIC2. In all beverages, ten compounds [tyrosol, sucrose, fructose, (α/β)-glucose, ethanol, malic, citric, gallic, and succinic acids] were identified and quantified. The highest phenolic concentrations [gallic acid (390.0µM) and tyrosol (380.0µM)] were found in Biolievito Bayanus (BBA) beverage. The new BBA beverage was used for investigating filtration process influence on chemical composition and antioxidant responses. Alcoholic content (unfiltered: 13.9°GL and filtered: 12.7°GL), antioxidant responses, and total phenolic contents were influenced by filtration process. The yeast type and unfiltered process were determinant for chemical content and antioxidant capacity of beverages. These results might be useful to private sector and future production and commercialization of araçá-boi beverages.

Evaluation of phenolic antioxidant capacity in beverages based on laccase immobilized on screen-printed carbon electrode modified with graphene nanoplatelets and gold nanoparticles

A simple and highly sensitive electrochemical biosensor based on laccase immobilized onto a gold nanoparticles/graphene nanoplatelets-modified screen-printed carbon electrode (LACC/AuNP/GNPl/SPCE) was developed for the determination of hydroquinone (HQ) and other phenolic compounds. The biosensor shows excellent electro-catalytic activity towards oxidation of hydroquinone at a potential of -0.05 V (vs Ag/AgCl, 3 M KCl) in phosphate buffer as supporting electrolyte (0.1 M, pH 7.0) using hydrodynamic amperometry.Analytical characteristics uncover that the LACC/AuNP/GNPl/SPCE comprises a wide linear range for the dependence of the signal on HQ concentrations from 4 to 130 µM with a detection limit (3σ) of 1.5 µM. The repeatability (5 measurements, 100 µM hydroquinone) is ±2% and the reproducibility (5 biosensors, 100 µM hydroquinone) is ±3%. Interference studies of most common compounds with the determination of hydroquinone demonstrated negligible effects.Finally, the biosensor and the analytical method were applied to the determination of phenolic antioxidant capacity (AOC) in wine and blueberry syrup based on Trolox (6‑hydroxy‑2,5,7,8-tetramethylchromane-2-carboxylic acid) and hydroquinone equivalents. The results were evaluated by using their calibration curves which were satisfactory and agreed well with the results obtained by the reference method Trolox Equivalent Antioxidant Capacity assay (TEAC-Assay).

Development of an assay to assess genotoxicity by particulate matter extract.

The current study describes a method for assessing the oxidative potential of common environmental stressors (ambient air particulate matter), using a plasmid relaxation assay where the extract caused single-strand breaks, easily visualised through electrophoresis. This assay utilises a miniscule amount (11 µg) of particulate matter (PM) extract compared to other, cell-based methods (~3,000 µg). The negative impact of air pollution on human health has been extensively recognised. Among the air pollutants, PM plays an eminent role, as reflected in the broad scientific interest. PM toxicity highly depends on its composition (metals and organic compounds), which in turn has been linked to multiple health effects (such as cardiorespiratory diseases and cancer) through multiple toxicity mechanisms; the induction of oxidative stress is considered a major mechanism among these. In this study, the PM levels, oxidative potential, cytotoxicity and genotoxicity of PM in the region of Larissa, Greece were examined using the plasmid relaxation assay. Finally, coffee extracts from different varieties, derived from both green and roasted seeds, were examined for their ability to inhibit PM-induced DNA damage. These extracts also exerted an inhibitory effect on xanthine oxidase and catalase, but had no effect against superoxide dismutase. Overall, this study highlights the importance of assays for assessing the oxidative potential of widespread environmental stressors (PM), as well as the antioxidant capacity of beverages and food items, with the highlight being the development of a plasmid relaxation assay to assess the genotoxicity caused by PM using only a miniscule amount.

Rapid sensing of antioxidant capacity based on electrochemiluminescence induced by electrochemically generated reactive oxygen species

A simple and rapid electrochemiluminescence (ECL) method for the measurement of antioxidant capacity using a portable ECL device with a screen-printed electrode is described. The ECL method is based on the luminous reaction of reactive oxygen species (ROS), luminol radicals and antioxidants. ROS are generated by the electrochemical reduction of dissolved oxygen and competitively react with the luminol and antioxidants. The ECL intensity depends on the antioxidant capacity because the radicals are neutralized by the antioxidants, suppressing the luminous reaction. An antioxidant standard curve was generated using different concentrations of known amounts of Trolox by ECL measurement and the detection limit for antioxidant capacity was found to be 0.06mM of Trolox. An antioxidant capacity of beverages (22 types) was evaluated by comparing with the standard curve of Trolox. The time necessary for the ECL measurement of antioxidant capacity is only two minutes after combining the sample solution with luminol on a screen-printed electrode.

DNA-based sensor against nitrite oxide radical: Evaluation of total antioxidant capacity in beverages

Reactive nitrogen and oxygen species are produced in cells and play an important role in the oxidative metabolism; when in abnormal concentrations, they are able to induce oxidative damage on biomolecules, namely in DNA. In this paper it is described, an electrochemical DNA-based sensor against NO radical developed for total antioxidant capacity (TAC) evaluation. The sensor consisted on dA20 (adenine-rich oligonucleotide) physically adsorbed into carbon paste electrode (CPE). When this dA20-CPE was damaged, by immersion in a freshly generated NO radical, a protective effect onto dA20 was observed in the presence of antioxidants (ascorbic, gallic, caffeic, p-coumaric acids). Electrochemical studies were performed through square wave voltammetry. The construction of the sensor is simple, fast and the results indicated that the DNA-based sensor is suitable, accurate, and can be used to the assessment of TAC in commercial samples of juices.

EVALUATION OF THE RADICALN,N-DIETHYL-1,4-FENILENEDIANIME (DEPD•+) AS A SPECTROPHOTOMETRIC PROBE FOR DETERMINING ANTIOXIDANT CAPACITIES IN BEVEREGES

Many well-established methods for determining the antioxidant capacities in several samples have been described in literature. However, DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) are the main two methods that utilize radicals as spectrophotometric probes for analysis. Nevertheless, these methods have certain limitations because of their slower kinetics, solvent polarity effects, the hydrophilicity and lipophilicity of the compounds, chemical costs, etc. In this study, a spectrophotometric method for determining the antioxidant capacity in beverages was developed based on an exploration of the cation radical derived from DEPD. This method was based on the oxidation of aromatic amines with Fe(III) ions at pH 4.0, which leads to their corresponding purple cation radicals (DEPD•+) with λmax values at 500 and 540 nm. The addition of an antioxidant after the formation of the radical leads to a reduction in color intensity that is proportional to the antioxidant concentration in the medium. Results obtained using this method were compared with the Folin-Ciocalteau, ABTS and DPPH methods in terms of applications in wines, teas, and infusions samples. Linear correlation analysis at a 95% confidence level was employed to compare the results, which were in good agreement with a correlation coefficient of r > 0.9000. Thus, the developed method was simple, accurate, and consistent with other assays for the determination of the total amount of phenolic compounds and antioxidant capacity.

Evaluation of the antioxidant capacity of cognacs and brandies by differential pulse voltammetry

Components of cognacs and brandies form anodic peaks at 0.44 and 0.59 V in the differential pulse voltammogram recorded on a glassy carbon electrode modified with multiwalled carbon nanotubes in phosphate buffer solution at pH 3.0. The effect of the pH of the supporting electrolyte and pulse parameters on the analytical signal is evaluated. It was found that the peak at 0.44 V is integral in nature; gallic acid contributes to this peak. The peak at 0.59 V is a result of the oxidation of ellagic acid. We developed a method for the evaluation of the antioxidant capacity (AOC) of cognacs and brandies by differential pulse voltammetry and tested it on nine samples. The total area of two oxidation steps was selected as a parameter characterizing the antioxidant properties. Antioxidant capacity was expressed in equivalents of ellagic acid per 100 mL of a beverage. Correlations between the AOC of beverages and their total AOC and ferric reducing power (r = 0.9752 and 0.9539 at P = 0.95, respectively) are found.

Chemical composition, antioxidant capacity and shelf life stability of blueberry and cranberry flavored maple sap water beverages (647.5)

Maple sap water is a by‐product of reverse osmosis filtration of maple sap during the production of maple syrup. The objective of this study was to develop blueberry and cranberry flavored beverages using maple sap water. The flavored sap water beverages were formulated using blueberry and cranberry concentrates, acidulant, and sugar and were pasteurized before bottling. Physicochemical characteristics, microbiological quality, ascorbic acid content, and antioxidant capacity of the beverages were analyzed during storage at 4 or 23 °C for 8 weeks. No growth of the total plate count, coliform, and yeast/mold in the beverages was seen initially, nor was it detected throughout the 8‐week storage either at 4 or 23 °C. The sugar content, pH, and titratable acidity for the flavored maple sap water beverages were significantly impacted by storage temperature, time and their interaction (P < 0.05). The storage temperature, time and their interaction significantly affected the area and peak of color absorption at 450 to 600 nm of flavored maple sap water beverages (P<0.01). The ascorbic acid content and total antioxidant capacity of flavored maple sap water beverages were significantly decreased during storage (P<0.01). Results showed that the maple sap water can be used for formulation of flavored functional beverage.

Electrochemical biosensor for assessment of the total antioxidant capacity of orange juice beverage based on the immobilizing DNA on a poly l-glutamic acid doped silver hybridized membrane

An electrochemical DNA damage biosensor for assessment of the antioxidant capacity in orange juice beverage was fabricated. The biosensor was constituted with a hybridized membrane of poly l-glutamic acid and Ag and an outside layer of chitosan (CS)/double stranded DNA (ds-DNA). The Fenton solution (Fe2+/H2O2) was used to generate hydroxyl radical (OH) and induce ds-DNA damage. The orange juice beverage and ascorbic acid (AA) could scavenge OH and protect ds-DNA from damage effectively. Based on this, the antioxidant capacities of the orange juice beverage and AA were studied by linear sweep voltammetry using Ru(NH3)63+ as indicator. The ultraviolet visible absorption spectrometry was also used to detect the ds-DNA damage and the antioxidant capacity with almost the same conclusions as the electrochemical method. The proposed biosensor exhibited good stability and reproducibility and was suitable for the assessment of the antioxidant capacity in beverages.

Decrease in the Antioxidant Capacity in Beverages Containing Tea Extracts during Storage

The aim of this work was to determine antioxidant capacity of beverages containing black, white, and green tea extracts using the photochemiluminescence method, and to monitor its changes based on the storage temperature and time. Samples were stored at two different temperatures (refrigerated at 4°C and laboratory temperature 22°C), analyzed after opening of the original package, and consequently after 4 and 7 days. Results of the antioxidant capacity are expressed as the standard equivalents, that is, ascorbic acid in mmol/L. The highest mean value of the antioxidant capacity was found after opening of the original package in fruit-juice-enriched samples and totaled 9.793 mmol/L. This group revealed significant dependence (P < 0.05) not only on the storage time, but also temperature. In samples without added fruit juices containing preservatives the value was 0.428 mmol/L. This group showed significant dependence (P < 0.05) on the decrease of antioxidant capacity only when based on the storage time. Samples without fruit juices or preservatives showed significant decrease in the antioxidant capacity (P < 0.05) after 4 days of storage based on the storage time. The dependence on temperature was revealed only after 7 days of storage.

Changes in Water-Soluble Vitamins and Antioxidant Capacity of Fruit Juice–Milk Beverages As Affected by High-Intensity Pulsed Electric Fields (HIPEF) or Heat during Chilled Storage

The effect of high-intensity pulsed electric fields (HIPEF) or thermal processes and refrigerated storage on water-soluble vitamins and antioxidant capacity of beverages containing fruit juices and whole (FJ-WM) or skim milk (FJ-SM) was assessed. Peroxidase (POD) and lipoxygenase (LOX) inactivation as well as color changes were also studied. High vitamin C retention was observed in HIPEF and thermally treated beverages, but a significant depletion of the vitamin during storage occurred, which was correlated with antioxidant capacity. HIPEF treatment did not affect the concentration of group B vitamins, which also remained constant over time, but thermally treated beverages showed lower riboflavin (vitamin B2) concentration. With regard to enzyme activity, thermal processing was more effective than HIPEF on POD and LOX inactivation. The color of the beverages was maintained after HIPEF processing and during storage. Consequently, HIPEF processing could be a feasible technology to attain beverages with fruit juices and milk with high vitamin content and antioxidant potential.

Electrocatalytic evaluation of DNA damage by superoxide radical for antioxidant capacity assessment

The integrity of DNA purine bases was herein used to evaluate the antioxidant capacity. Unlike other DNA-based antioxidant sensors reported so far, the damaging agent chosen was the O 2 - radical enzymatically generated by the xanthine/xanthine oxidase system. An adenine-rich oligonucleotide was adsorbed on carbon paste electrodes and subjected to radical damage in the presence/absence of several antioxidant compounds. As a result, partial damage on DNA was observed. A minor product of the radical oxidation was identified by cyclic voltammetry as a diimine adenine derivative also formed during the electrochemical oxidation of adenine/guanine bases. The protective efficiency of several antioxidant compounds was evaluated after electrochemical oxidation of the remaining unoxidized adenine bases, by measuring the electrocatalytic current of NADH mediated by the adsorbed catalyst species generated. A comparison between O 2 - and OH radicals as a source of DNA lesions and the scavenging efficiency of various antioxidant compounds against both of them is discussed. Finally, the antioxidant capacity of beverages was evaluated and compared with the results obtained with an optical method.

DNA-based biosensor for the electrocatalytic determination of antioxidant capacity in beverages

Reactive oxygen species (ROS) are produced as a consequence of normal aerobic metabolism and are able to induce DNA oxidative damage. At the cellular level, the evaluation of the protective effect of antioxidants can be achieved by examining the integrity of the DNA nucleobases using electrochemical techniques. Herein, the use of an adenine-rich oligonucleotide (dA 21) adsorbed on carbon paste electrodes for the assessment of the antioxidant capacity is proposed. The method was based on the partial damage of a DNA layer adsorbed on the electrode surface by OH radicals generated by Fenton reaction and the subsequent electrochemical oxidation of the intact adenine bases to generate an oxidation product that was able to catalyze the oxidation of NADH. The presence of antioxidant compounds scavenged hydroxyl radicals leaving more adenines unoxidized, and thus, increasing the electrocatalytic current of NADH measured by differential pulse voltammetry (DPV). Using ascorbic acid (AA) as a model antioxidant species, the detection of as low as 50 nM of AA in aqueous solution was possible. The protection efficiency was evaluated for several antioxidant compounds. The biosensor was applied to the determination of the total antioxidant capacity (TAC) in beverages.

Evaluation of spectrophotometric methods for antioxidant compound measurement in relation to total antioxidant capacity in beverages

The validity of different colorimetric methods used to quantify various families of antioxidant compounds was evaluated with standard compounds. The colorimetric tests for global evaluation of flavonoids, anthocyans, and flavanols were found generally unreliable, as reactions could be different for individual compounds within a family (anthocyanins or flavonols or flavan-3-ols) and not specific to one family. In the flavonoid test, for example, flavonols reacted very well, anthocyanins did not react, and flavanons reacted only slightly. The same methods were applied also to beverages known for their antioxidant content (apple, orange, grape, and vegetable juices, ice tea, and red wine) and the data were compared with the results of HPLC analysis of specific compounds. The values obtained in a colorimetric test were generally higher than the sum of the values obtained for the corresponding individual compounds by HPLC analysis, mainly because other compounds can interfere with the colorimetric tests. For example, in wine, anthocyanin concentrations obtained by colorimetric test were 9068 ± 1407 μmol/100 ml (mean ± SEM), higher than the sum of the six main anthocyanidins detected by HPLC, only 41 μmol/100 ml. The relative antioxidant capacity values determined for beverages on the basis of colorimetric tests could exceed by far the values previously measured in radical-scavenging tests (for instance, the antioxidant capacity attributable to anthocyans in wine on the basis of the colorimetric test was 50 times higher than the total antioxidant capacity measured by the ORAC assay). In conclusion, colorimetric tests for flavonoids, anthocyans, and flavanols appeared generally unreliable for estimating their content and thus the antioxidant capacity reliable to these compounds.