Origin of the Variability of the Antioxidant Activity Determination of Food Material (original) (raw)
Related papers
Analytical Methods Used in Determining Antioxidant Activity: A Review
International Journal of Molecular Sciences
The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothia...
Methods for the Determination of Antioxidant Capacity in Food and Raw Materials
A comprehensive description of the most frequently used methods to determine the antioxidant activity in food and raw materials is given. The methods are classified into two categories, depending on the type of the assessment carried out. Several methods for the assessment of antioxidant efficacy using free radical scavenging such as Oxygen Radical Absorbance Capacity Assay (ORAC), Total Radical Trapping Antioxidant Parameter assay (TEAC), Ferric reducing antioxidant power assay (FRAP) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) assay are described. An example of methods based on the assessment of antioxidant efficacy using significant biological substrates is also presented. Critical opinions concerning the proposed methods are presented.
Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method. This overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nutraceutical, and dietary supplement industries. From evaluation of data presented at the First International Congress on Antioxidant Methods in 2004 and in the literature, as well as consideration of potential end uses of antioxidants, it is proposed that procedures and applications for three assays be considered for standardization: the oxygen radical absorbance capacity (ORAC) assay, the Folin-Ciocalteu method, and possibly the Trolox equivalent antioxidant capacity (TEAC) assay. ORAC represent a hydrogen atom transfer (HAT) reaction mechanism, which is most relevant to human biology. The Folin-Ciocalteu method is an electron transfer (ET) based assay and gives reducing capacity, which has normally been expressed as phenolic contents. The TEAC assay represents a second ET-based method. Other assays may need to be considered in the future as more is learned about some of the other radical sources and their importance to human biology. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.
Methods for Total Antioxidant Activity Determination: A Review
Biochemistry & Analytical Biochemistry, 2012
Health Benefits of Antioxidants Recently, antioxidants have attracted considerable attention in relation to radicals and oxidative stress, cancer prophylaxis and therapy, and longevity [3]. Phenols and polyphenols are the target analytes in many such cases; they may be detected by enzymes like tyrosinase or other phenol oxidases, or even by plant tissues containing these enzymes [4-18]. The recommendations based on epidemiological studies are such, that fruits, vegetables and less processed staple foods ensure the best protection against the development of diseases caused by oxidative stress, such as cancer, coronary heart disease, obesity, type 2 diabetes, hypertension and cataract [19]. The explanation consists in the beneficial health effect, due to antioxidants present in fruit and vegetables [20]. There are numerous antioxidants in dietary plants: carotenoids, phenolic compounds, benzoic acid derivatives, flavonoids, proanthocyanidins, stilbenes, coumarins, lignans, and lignins [21]. Of the 50 analysed food products with high antioxidant content [20], 13 were spices, 8 were fruits and vegetables, 5 were berries, 5 were chocolatebased, 5 were breakfast cereals, and 4 were nuts or seeds. Considering the typical serving sizes, blackberries, walnuts, strawberries, artichokes, cranberries, brewed coffee, raspberries, pecans, blueberries, ground cloves, grape juice and unsweetened baking chocolate were at the top of the classification [20]. Fruit juices, beverages and hot drinks contain high amounts of antioxidants, like polyphenols, vitamin C, vitamin E, Maillard reaction products, β-carotene, and lycopene [22]. The consumption of fruit juices, beverages and hot drinks was found to reduce the morbidity and mortality caused by degenerative diseases [23-28]. Antioxidants are known to play a key role in the protective influence exerted by plant foods [28-32]. Epidemiologic studies that analyse the health
2008
Due to differences in the functional quality of natural extracts, we have also faced differences in their effectiveness. So, it was intended to assess the antioxidant activity of natural extracts in order to attain their functional quality. It was observed that all the extracts (brown and green propolis, Ginkgo biloba and Isoflavin Beta®) and the standard used (quercetin) showed antioxidant activity in a dose-dependent manner with IC 50 values ranging from 0.21 to 155.28 μg mL-1 (inhibition of lipid peroxidation and scavenging of the DPPH • assays). We observed a high correlation (r 2 = 0.9913) among the antioxidant methods; on the other hand, the antioxidant activity was not related to the polyphenol and flavonoid content. As the DPPH • assay is a fast method, presents low costs and even has a high correlation with other antioxidant methods, it could be applied as an additional parameter in the quality control of natural extracts. RESUMEN. "Evaluación de la actividad antioxidante como parámetro adicional para lograr la calidad funcional de extractos naturales". Debido a las diferencias en la calidad funcional de extractos naturales, nosotros hemos advertido también diferencias en su efectividad, por lo que se pretende estimar la actividad antioxidante de extractos naturales para lograr su calidad funcional. Fue observado que todos los extractos (propolis marrón y verde, Ginkgo biloba e Isoflavin Beta®) y el patrón usado (quercetina) mostraron actividad antioxidante de una manera dosis-dependiente con valores de IC 50 que van de 0,21 a 155,28 al μg mL-1 (inhibición de la peroxidación lipídioca y captación de radicales libres del DPPH •). Se observó una alta correlación (r 2 = 0,9913) entre los métodos antioxidantes y por otro lado la actividad antioxidante no estuvo relacionada con el contenido del polifenoles ni de flavonoides. Como el análisis del DPPH • es un método rápido, presenta costos bajos e incluso tiene una correlación alta con otros métodos antioxidantes, este método podría utilizarse como un parámetro adicional en el control de calidad de extractos naturales.
Spectroscopic methods provide with very useful qualitative and quantitative information about the biochemistry and chemistry of antioxidants. Near infrared (NIR) and mid infrared (MIR) spectroscopy are considered as powerful, fast, accurate and non-destructive analytical tools that can be considered as a replacement of traditional chemical analysis. In recent years, several reports can be found in the literature demonstrating the usefulness of these methods in the analysis of antioxidants in different organic matrices. This article reviews recent applications of infrared (NIR and MIR) spectroscopy in the analysis of antioxidant compounds in a wide range of samples such as agricultural products, foods and plants.
The chemical diversity of natural antioxidants (AOXs) makes it difficult to separate, detect, and quantify individual antioxidants from a complex food/biological matrix. Moreover, the total antioxidant power is often more meaningful to evaluate health beneficial effects because of the cooperative action of individual antioxidant species. Currently, there is no single antioxidant assay for food labeling because of the lack of standard quantification methods. Antioxidant assays may be broadly classified as the electron transfer (ET)-and hydrogen atom transfer (HAT)-based assays. The results obtained are hardly comparable because of the different mechanisms, redox potentials, pH and solvent dependencies, etc. of various assays. This project will aid the identification and quantification of properties and mutual effects of antioxidants, bring a more rational basis to the classification of antioxidant assays with their constraints and challenges, and make the results more comparable and understandable. In this regard, the task group members convey their own experiences in various methods of antioxidants measurement.
Review on antioxidants and evaluation procedures
Chinese journal of integrative medicine, 2017
Antioxidants are the substances that are capable of counteracting the damaging effects of the physiological process of oxidation occur in animal tissues. These may be nutrients (vitamins and minerals) as well as enzymes (proteins) in our body that assist in chemical reactions. They are believed to play a role in preventing the development of chronic diseases like cancer, diabetes, heart disease, stroke, Alzheimer's disease, rheumatoid arthritis, and cataracts etc. The present review article emphasizes on the various aspects of oxidants and antioxidants viz. definition, types, causes, mechanism, functions, adverse effects along with various in vivo and in vitro models of evaluation of antioxidant activity of new molecule, compounds or any plant or plant part. This review is one of its kinds which will be of great importance for researchers working in this area in search of antioxidant moieties and their biological evaluation.
Measurement of antioxidant activity
Antioxidants play an important role in food preservation by inhibiting oxidation processes and contributing to health promotion rendered by many dietary supplements, nutraceuticals and functional food ingredients. Antioxidant activity can be monitored by a variety of assays with different mechanisms, including hydrogen atom transfer (HAT), single electron transfer (ET), reducing power, and metal chelation, among others. Understanding the principle mechanisms, advantages and limitations of the measurement assays is important for proper selection of method(s) for valid evaluation of antioxidant potential in desired applications.
Nutrition & Food Measurement of Antioxidant Activity in Selected Food Products and Nutraceuticals
Measurement of antioxidant activity using in vitro assays is paramount in the evaluation of various food products and nutraceuticals for determining antioxidant benefits. This relates to the fact that increased antioxidant levels can protect the human body from free radical damage. The objective of this study was to quantify the antioxidant activity of selected food products and nutraceuticals using a spectrophotometric assay. Using Efferdent tablets and isotonic saline diluent, antioxidant levels could be determined by the amount of FD & C Blue No. 2 remaining after incubation at 37°C for 25 minutes. The antioxidant activity of a 500 mg quantity of vitamin C (ascorbic acid) was used as standard. The results obtained indicated that agave nectar syrup and xylitol sweetener (in descending order) exhibited higher antioxidant properties than all the other commercial sweeteners tested. Grapefruit was found to have the highest antioxidant activity of those common citrus fruits tested. Popular contemporary antioxidant beverages, such as strawberry-kiwi blend tend to have very high antioxidant activity since they contain d-alpha tocopheryl acetate (a form of vitamin E). Among the herbal nutraceuticals tested, spirulina and red yeast rice exhibited abundant antioxidant activities, whereas graviola was found to have absolutely no antioxidant properties. Thieves' oil was observed to have high antioxidant properties due to the synergism of the five oils in the preparation. Test results indicated a variable degree of antioxidant activity in foods and nutraceuticals compared to a standard antioxidant of 500 mg of vitamin C (ascorbic acid). Citrus fruits occupy the highest level of antioxidant activity overall, followed by antioxidant containing beverages and selected herbal products.