A study of the antioxidant capacity of oak wood used in wine ageing and the correlation with polyphenol composition

The antioxidant capacity of oak wood used in the ageing of wine was studied by four different methods: measurement of scavenging capacity against a given radical (ABTS, DPPH), oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP). Although, the four methods tested gave comparable results for the antioxidant capacity measured in oak wood extracts, the ORAC method gave results with some differences from the other methods. Non-toasted oak wood samples displayed more antioxidant power than toasted ones due to differences in the polyphenol compositon. A correlation analysis revealed that ellagitannins were the compounds mainly responsible for the antioxidant capacity of oak wood. Some phenolic acids, mainly gallic acid, also showed a significant correlation with antioxidant capacity

Role of antioxidant supplementation and exercise regimen in handling oxidative stress from natural PM2.5 exposure due to boreal forest fire

Thesis (M.S.) University of Alaska Fairbanks, 2019Particulate matter 2.5 (PM2.5) exposure induces oxidative stress that causes many negative health outcomes such as cancer, cardiovascular disease and neurodegenerative disease. Research shows that dietary antioxidants and an up-regulated endogenous antioxidant response from exercise play key roles in the antioxidant defense against oxidative stress. This study is the first to use an animal model to investigate the cumulative effects of using lifestyle interventions of antioxidant supplementation (Arthrospira platensis) and exercise regimen on the antioxidant response before, during, and after ambient PM2.5 exposure. In a two-factorial, longitudinal design, sled dogs (n=48) were divided into four groups (exercise and supplemented, exercise, supplemented, and control) to (1) test the effects of exercise and antioxidant regimen on antioxidant response after one month of implemented exercise and supplementation protocol and (2) measure the antioxidant response of all groups during and after a natural forest fire event in 2015. Commercial assays for Total antioxidant Power (TAP) and the enzymatic antioxidant Superoxide Dismutase (SOD) were used as markers for the total antioxidant response and the endogenous response at all time points. During the forest fire, SOD was increased 5-10-fold over pre/post-exposure levels in all groups suggesting potential implication for using SOD as a marker for the acute response to environmental stress. TAP was increased in the exercise groups after one month of exercise protocol implementation, demonstrating the cytoprotective increase of antioxidants after repeated exercise.Chapter 1: Introduction -- 1.1 PM2.5 -- 1.2 Oxidative stress and exercise -- 1.3 Antioxidants -- 1.4 Significance and research hypothesis -- Chapter 2 The effects of spirulina supplementation and exercise regimen on the antioxidant response to PM2.5 exposure in sled dogs -- 2.1 Introduction -- 2.2 Materials and methods -- 2.2.1 Animals -- 2.2.2 Experimental design -- 2.2.4 Exercise -- 2.2.5 Blood sampling -- 2.2.6 Biochemical analyses -- 2.2.7 Statistics -- 2.3 Results -- 2.4 Discussion -- 2.5 Conclusions -- Chapter 3 Conclusions and future directions -- References

Paradoxical roles of antioxidant enzymes:Basic mechanisms and health implications

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate “paradoxical” outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of “antioxidant” nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that “paradoxical” roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways

Amperometric enzyme sensor to check the total antioxidant capacity of several mixed berries. comparison with two other spectrophotometric and fluorimetric methods

The aim of this research was to test the correctness of response of a superoxide dismutase amperometric biosensor used for the purpose of measuring and ranking the total antioxidant capacity of several systematically analysed mixed berries. Several methods are described in the literature for determining antioxidant capacity, each culminating in the construction of an antioxidant capacity scale and each using its own unit of measurement. It was therefore endeavoured to correlate and compare the results obtained using the present amperometric biosensor method with those resulting from two other different methods for determining the total antioxidant capacity selected from among those more frequently cited in the literature. The purpose was to establish a methodological approach consisting in the simultaneous application of different methods that it would be possible to use to obtain an accurate estimation of the total antioxidant capacity of different mixed berries and the food product

Effect of drying process on antioxidant properties of date palm fruits

Aim. In order to identify antioxidant activities and phenolic compound, two varieties of date palm (Mazfati and Kalute varieties) (Phoenix dactylifera) fruits (DPF) from Iran systematically evaluated. Methods. Antioxidant activity determined using typical methods such as DPPH, reducing power and total antioxidant method. The total phenolic content of the dates was measured using Folin-Ciocalteau method. The included samples were gathered at three stages of khalaal, rutab, tamr and dried date from Sam and Jiroft date. The total phenolic content ranged from 1074, 856.4 and 723.8 in Mozafati variety and 921.5, 723.5 and 785.3 mg gallic acid equivalents (GAE/100-g-dw sample) in Kalute variety for khalal, rutab and tamr stage, respectively. Results. In both varieties antioxidant activities and total phenolic content decreased by ripening stages. Result of drying process showed that total phenolic content and antioxidant activities varied from temperature and decreased by increase of drying temperature. Conclusion. This research demonstrates Iranian dates could be potential rich resources of natural antioxidants, and could be developed into functional foods or drug for the prevention and treatment of diseases caused by oxidative stress

Turmeric and black pepper spices decrease lipid peroxidation in meat patties during cooking.

Spices are rich in natural antioxidants and have been shown to be potent inhibitors of lipid peroxidation during cooking of meat. Turmeric contains unique conjugated curcuminoids with strong antioxidant activity. Piperine, one of the main constituents of black pepper, is known to increase the bioavailability of curcuminoids in mouse and human studies when consumed with turmeric. We investigated whether adding black pepper to turmeric powder may further inhibit lipid peroxidation when added to meat patties prior to cooking. The addition of black pepper to turmeric significantly decreased the lipid peroxidation in hamburger meat. When investigating the antioxidant activity of the main chemical markers, we determined that piperine did not exhibit any antioxidant activity. Therefore, we conclude that other black pepper ingredients are responsible for the increased antioxidant activity of combining black pepper with turmeric powder

Influence of Processing on Bioactive Substances Content and Antioxidant Properties of Apple Purée from Organic and Conventional Production in Poland

The organic food market is developing dynamically in many European countries and therefore studies concerning the nutritive value of organically produced foods are becoming increasingly important. It was found appropriate to conduct studies on selected bioactive substances and antioxidant properties of apple preserves prepared from organic vs. conventional apples. Three apple cultivars, Lobo, Boskoop and Cortland, were grown in organic and conventional orchards in the Mazovia region in Poland. Dry matter, total phenols, vitamin C, total flavones and antioxidant activity were determined in fresh and pasteurized apple purée. The apple purée prepared from the organic apples contained significantly more total phenols, vitamin C, total flavones and showed a higher antioxidant capacity than the preserves prepared from conventional apples. Processing had a negative effect on both antioxidant capacity and bioactive substances. After pasteurization, the content of vitamin C, total phenols and flavones and antioxidant properties have decreased in the apple purée from both agricultural systems (organic and conventional)

Black Beans, Fiber, and Antioxidant Capacity Pilot Study: Examination of Whole Foods vs. Functional Components on Postprandial Metabolic, Oxidative Stress, and Inflammation in Adults with Metabolic Syndrome.

Beans (Phaseolus vulgaris) contain bioactive components with functional properties that may modify cardiovascular risk. The aims of this pilot study were to evaluate the ability of black beans to attenuate postprandial metabolic, oxidative stress, and inflammatory responses and determine relative contribution of dietary fiber and antioxidant capacity of beans to the overall effect. In this randomized, controlled, crossover trial, 12 adults with metabolic syndrome (MetS) consumed one of three meals (black bean (BB), fiber matched (FM), and antioxidant capacity matched (AM)) on three occasions that included blood collection before (fasting) and five hours postprandially. Insulin was lower after the BB meal, compared to the FM or AM meals (p < 0.0001). A significant meal × time interaction was observed for plasma antioxidant capacity (p = 0.002) revealing differences over time: AM > BB > FM. Oxidized LDL (oxLDL) was not different by meal, although a trend for declining oxLDL was observed after the BB and AM meals at five hours compared to the FM meal. Triglycerides and interleukin-6 (IL-6) increased in response to meals (p < 0.0001). Inclusion of black beans with a typical Western-style meal attenuates postprandial insulin and moderately enhances postprandial antioxidant endpoints in adults with MetS, which could only be partly explained by fiber content and properties of antioxidant capacity

Effect of Steaming and Boiling on the Antioxidant Properties and Biogenic Amines Content in Green Bean (Phaseolus vulgaris) Varieties of Different Colours

Effects of boiling and steaming cooking methods were studied on total polyphenols, antioxidant capacity, and biogenic amines of three green bean varieties, purple, yellow, and green.The vegetables gave good values both for antioxidant capacity and for phenolics content, with the purple variety being the richest in healthful components. Both the heat treatments affected the antioxidant properties of these vegetables, with boiling that reduced the initial antioxidant capacity till 30%in the yellowvariety, having the same trend for total polyphenols, with the major decrement of 43% in the green variety. On the contrary, biogenic amines significantly increased only after boiling in green and yellow variety, while purple variety did not show any changes in biogenic amines after cooking. The steaming method showed being better cooking approach in order to preserve the antioxidant properties of green beans varieties and to maintain the biogenic amines content at the lowest level