Phenolic Compounds In Foods Research Articles

Nanofibrous membrane based tyrosinase-biosensor for the detection of phenolic compounds

A tyrosinase-modified electrode is described to be used as amperometric biosensor for the detection of phenolic compounds in food. The enzyme has been immobilized by drop-coating on a glassy carbon electrode covered by a polyamidic nanofibrous membrane prepared by electrospinning. With respect to others, the selectivity of the designed tyrosinase-biosensor resulted modified by the presence of the nanostructured coating which seems to affect the permeability of phenols as a function of the pH of the solution and of their dissociation constants. The biosensor exhibits a response time of 16 s, a detection limit of 0.05 μM, and a linearity up to 100 μM (slope: −304 nA μM −1; intercept: −191 nA, r 2 = 0.996, n = 19). Among others, it can be successfully used for monitoring in real time the release kinetics of phenols encapsulated in polymeric microcapsules.

Correlations of Antioxidant Activity against Phenolic Content Revisited: A New Approach in Data Analysis for Food and Medicinal Plants

This study presents a new approach to analyze data correlating total antioxidant activity and total phenolic compounds in foods. The correlation of both variables is a common practice found in the literature. The purpose of these correlations is to determine the contribution of phenolics to the total antioxidant activity of foods. When low R(2) values are obtained, the general conclusion is that other compounds have a higher relevance than phenolics in the total antioxidant activity of the samples. However, these correlations do not consider differences in the phenolic profiles that can be qualitatively (type of phenolics present) and quantitatively (the relative amounts or proportions of phenolics present) among the samples under investigation. The new approach to analyze these simple correlations presented herein takes into consideration the phenolic profiles and provides information on the effectiveness of phenolics present in the samples to neutralize free radicals. Data obtained from carrots stored under conditions of air and hyperoxia (superatmospheric oxygen) are used to exemplify how to apply this new approach.

ANTIOXIDANT ACTIVITY OF EXTRACT OF ADZUKI BEAN AND ITS FRACTIONS

ABSTRACT Phenolic compounds were extracted from adzuki bean using 80% (v/v) aqueous acetone. Crude extract was applied onto a Sephadex LH‐20 column. Fraction I, consisting of low‐molecular‐weight phenolics, was eluted from the column using ethanol. Fraction II, consisting of tannins, was obtained using water/acetone (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fractions showed antioxidant and radical scavenging properties as revealed using a β‐carotene‐linoleate model system, the total antioxidant activity (TAA) method, the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity and reducing power evaluation. Results of these assays showed highest values when tannins (fraction II) were tested. For example, the TAA of the tannin fraction was 4.17 µmol Trolox/mg, whereas extract and fraction I showed 1.76 and 1.40 µmol Trolox/mg, respectively. The content of total phenolics in fraction II was the highest (189 mg/g). The content of tannins in this fraction determined using the vanillin method and expressed as absorbance units at 500 nm/1 g was 213. There were 29 compounds (hydroxycinnamics, procyanidins, gallates, flavonols, dihydroflavonols, dihydrochalcones) identified in the crude extract using a high‐performance liquid chromatography with photodiode array and mass spectrometry detectors (HPLC‐PAD‐MS) method. Catechin and epicatechin glucosides, procyanidin dimers, myricetin and protocatechuic acid were the dominant phenolics in the extract. PRACTICAL APPLICATIONSResults showing the antioxidant activity of adzuki bean extract and its fraction can be useful for producers of healthy foods. The tannin fraction separated from adzuki can be applied for production of natural antioxidant preparations. The results of chemical analysis are valuable for databases of food phenolic compounds.

Profiling methods for the determination of phenolic compounds in foods and dietary supplements.

Profiling methods are needed that separate and detect all the phenolic compounds in a single extract of a food material. These methods must be comprehensive, rapid, and rich in spectral information. Fourteen methods that meet, or have the potential to meet, these criteria have been selected from the recent literature for review. In general, the methods employ a single aqueous methanol extraction, separation on a reversed-phase C column, and detection by UV/vis spectroscopy and mass spectrometry. The variations in extraction, separation, and detection are discussed. An increasingly important aspect of these methods is the archiving of data to permit cross-comparison of samples and standards and retrospective analysis. This review shows that the necessary technology is available to achieve the desired analytical goals.

Food Phenolics, Pros and Cons: A Review

Phenolic compounds like simple phenols, flavonoids, and phenolic acids are commonly in foods of plant origin. Several studies, including animal and epidemiological investigations, have demonstrated that phenolic compounds in foods possess positive attributes such as anticarcinogenesis, antioxidant potential, antiviral activity, antimicrobial activity, and antimutagenic activity. However, other studies have shown that the same phenolics have negative attributes such as carcinogenic activity and antinutritional activity, as well as imparting negative attributes to foods. This review summarizes the information about food phenolics and presents the most current knowledge with respect to its role in human health, food attributes, and toxicity among others.

Bioavailability of Phenolic Compounds

Phenolic compounds in foods originate from one of the main classes of secondary metabolites in plants. They are essential for the growth and reproduction of plants, and are produced as a response for defending injured plants against pathogens. In recent years, there is a growing interest in phenolic compounds and their presumed role in the prevention of various degenerative diseases, such as cancer and cardiovascular diseases. The importance of antioxidant activities of phenolic compounds and their possible usage in processed foods as a natural antioxidant have reached a new high in recent years. The absorption and bioavailability of phenolics in humans are also controversial. Data on these aspects of phenolics are scarce and merely highlight the need for extensive investigations of the handling of phenolics by the gastrointestinal tract and their subsequent absorption and metabolism. In this article, absorption, metabolism, and the bioavailability of phenolic compounds are reviewed.

Fenólicos totais e atividade antioxidante do extrato aquoso de broto de feijão-mungo (Vigna radiata L.)

OBJETIVO: Considerando a importância dos compostos fenólicos em alimentos e que o broto de feijão-mungo vem sendo incluído na culinária brasileira, este estudo teve como objetivo quantificar o teor de fenólicos totais deste vegetal e avaliar a ação antioxidante do seu extrato aquoso. MÉTODOS: Os compostos fenólicos foram extraídos por quatro sistemas de solventes e dois métodos de extração, os quais foram diferenciados no tempo (2 e 1h) e número de extrações (2 e 3 extrações). Os fenólicos totais dos extratos foram quantificados por método espectrofotométrico. RESULTADOS: Os extratos obtidos com água à temperatura ambiente (28ºC), nos dois métodos de extração, foram os que apresentaram maior quantidade de fenólicos totais, sem contudo apresentar diferença significativa entre eles. O método II, que consistiu de três extrações em 1h, pode ser considerado o melhor por ter utilizado menor tempo de extração. O extrato aquoso em sistema modelo b-caroteno/ácido linoléico exibiu ação antioxidante (48,07% de inibição da oxidação), entretanto foi inferior ao padrão BHT. CONCLUSÃO: O broto de feijão-mungo possui considerável quantidade de fenólicos totais, compostos responsáveis por sua ação antioxidante, cujo consumo pode proporcionar efeitos benéficos à saúde.

Phenolic Compounds in Plant Foods: Chemistry and Health Benefits

Phenolic compounds in food and plant materials belong to the simple phenols, phenolic acids, coumarins, flavonoids, stilbenes, tannins, lignans and lignins, all of which are considered as secondary plant metabolites. These compounds may be synthesized by plants during normal development or in response to stress conditions. Phenolics are not distributed uniformly in plants. Insoluble phenolics are components of cell walls while soluble ones are present in vacuoles. A cursory account of phenolics of cereals, beans, pulses, fruits, vegetables and oilseeds is provided in this overview. The information on the bioavailability and absorption of plant phenolics remains fragmentary and diverse. Pharmacological potentials of food phenolics are extensively evaluated. However, there are many challenges that must be overcome in order to fully understand both the function of phenolics in plant as well as their health effects.

A Comparative Study on the Various In Vitro Assays of Active Oxygen Scavenging Activity in Foods

ABSTRACT: Various in vitro assays of active oxygen‐scavenging activity in foods were compared by evaluating the activity of 13 food phenolic compounds and Trolox. 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH)‐HPLC and liposome oxidation methods were sensitive for these compounds, while deoxyribose oxidation and Randox kit methods were less sensitive. The deoxyguanosine oxidation method could not determine the activity since food polyphenols were pro‐oxidative in this assay. Among these assays, the DPPH‐HPLC method was shown to be the best since the liposome oxidation method is affected more by the structure of phenolic compounds than the DPPH‐HPLC method.

An Overview of Analytical Chemistry of Phenolic Compounds in Foods

A review is presented with references to the most important work dealing with the polyphenolic compounds taking account different aspects related with analytical chemistry of these compounds such as distribution, preparation, and/or treatment of sample and analytical techniques applied to their determination in foods. Contributions from 1985 to date are discussed.

Phenolic Composition and Antioxidant Activity of Prunes and Prune Juice (Prunus domestica)

Phenolic compounds in foods have been associated with reduced incidences of heart disease by acting as antioxidants for low-density lipoprotein (LDL). Commercial prune and prune juice extracts (Prunus domestica cv. French) were analyzed for phenolics by reversed phase HPLC with diode array detection and tested for the ability to inhibit the Cu2+-catalyzed oxidation of human LDL. The mean concentrations of phenolics were 1840 mg/kg, 1397 mg/kg, and 441 mg/L in pitted prunes, extra large prunes with pits, and prune juice, respectively. Hydroxycinnamates, especially neochlorogenic acid, and chlorogenic acid predominated, and these compounds, as well as the prune and prune juice extracts, inhibited the oxidation of LDL. The pitted prune extract inhibited LDL oxidation by 24, 82, and 98% at 5, 10, and 20 μM gallic acid equivalents (GAE). The prune juice extract inhibited LDL oxidation by 3, 62, and 97% at 5, 10, and 20 μM GAE. These data indicate that prunes and prune juice may provide a source of dietary anti...

Phenolic compounds in food and their effects on health. 1, analysis, occurrence and chemistry, edited by Chi‐Tang Ho, Chang Y. Lee, and Mon‐Tuan Huang, American Chemical Society Series, Vol. 506, ACS, 1992. No. of pages: 338, price £49.00. ISBN 0–8412–2475–7

Flavour and Fragrance JournalVolume 8, Issue 3 p. 170-170 Book Review Phenolic compounds in food and their effects on health. 1, analysis, occurrence and chemistry, edited by Chi-Tang Ho, Chang Y. Lee, and Mon-Tuan Huang, American Chemical Society Series, Vol. 506, ACS, 1992. No. of pages: 338, price £49.00. ISBN 0–8412–2475–7 First published: May/June 1993 https://doi.org/10.1002/ffj.2730080309AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume8, Issue3May/June 1993Pages 170-170 RelatedInformation

Phenolic compounds in food and their effects on health. 11, antioxidants and cancer prevention, edited by Mon‐Tuan Huang, Chi‐Tang Ho, and Chang Y. Lee, American Chemical Society Series, Vol. 507, ACS, 1992. No. of pages: 402, price £55.00. ISBN 0–8412–2476–5

Phenolic compounds in food and their effects on health. 11, antioxidants and cancer prevention, edited by Mon‐Tuan Huang, Chi‐Tang Ho, and Chang Y. Lee, American Chemical Society Series, Vol. 507, ACS, 1992. No. of pages: 402, price £55.00. ISBN 0–8412–2476–5

Phenolic compounds in food and their effects on health: v.1: Analysis, occurrence, and chemistry; v.2: Antioxidants and cancer prevention

Phenolic compounds in food and their effects on health: v.1: Analysis, occurrence, and chemistry; v.2: Antioxidants and cancer prevention

Dose-dependent inhibitory effect of phenolic compounds in foods on nonheme-iron absorption in men

Nonheme-iron absorption from a typical Southeast Asian meal was studied to examine the effect of a common vegetable, Yod Kratin, which contains a considerable amount of iron-binding phenolic groups. Yod Kratin (leaves of the lead tree) is a very popular vegetable in Thailand. It is consumed at least once a week year round, sometimes every day, together with the main meal. With a common portion size of the vegetable (20 g), iron absorption was reduced by almost 90%. As little as 5 g inhibited iron absorption by 75%. Addition of ascorbic acid partly counteracted inhibition. Adding 100 mg ascorbic acid reduced inhibition of iron absorption from 5 g Yod Kratin by half and the inhibition from 10 g Yod Kratin by a quarter. The study illustrates the marked effect of iron-binding phenolic compounds on iron nutrition and, thus, the importance of acquiring knowledge of the content of such compounds in different foods.