Important Source Of Phenolic Compounds Research Articles

Effect of microwave drying and oven drying on the water activity, color, phenolic compounds content and antioxidant activity of coconut husk (Cocos nucifera L.).

The coconut (Cocos nucifera L.) husk is basically composed by fiber and pith material and remained under-utilized. This is an important source of phenolic compounds that could be used as functional ingredients. The aim of this study was to determine the effect of: oven-drying (OD) and microwave drying (MD), on the water activity, color, phenolic compound content and antioxidant activity of coconut husk. The OD was performed at 60°C for 12h and MD was performed at 900W for 10min. The total phenolic content (TPC) in fresh coconut husk was 64.2mg GAE/gdrywt and significant higher than observed after OD and MD of 35.8 and 45.5mg GAE/gdrywt, respectively. Ten phenols were identified in fresh and dehydrated coconut husks. The husk MD showed an increase in the content of gallic, 4-hydroxybenzoic, ferulic and syringic acids and epicatechin compared with the fresh; while coconut husk OD and MD, showed a decrease in the content of vanillic acid, vanillin, catequin and kaempferol. The antioxidant activity decreased after both OD and MD. However, MD resulted in a better antioxidant activity in husk than OD. MD of husk resulted into better retention of preserved color, TPC and TFC than OD.

Effect of Prosopis sp. honey on the growth and fermentative ability of Pediococcus pentosaceus and Lactobacillus fermentum

Honey is widely known for having antimicrobial and antioxidant activity. These abilities are attributed to honey hydrogen peroxide (H2O2) and polyphenols. Polyphenols also exert beneficial effect on some species of lactic acid bacteria (LAB). In this study, we evaluate the effect of Prosopis sp. honey on the growth and fermentative activity of Pediococcus pentosaceus and Lactobacillus fermentum. Prosopis sp. honey was found to be an important source of phenolic compounds, especially flavonoids, being their average content superior to other honeys. LAB assessed in this study exhibited different responses to the presence of honey. P. pentosaceus was able to develop in concentrations of honey up to 25% (w/v), whilst L. fermentum showed high sensitivity, being affected both growth and fermentative activity. However, as a result of LAB fermentative capacity, the total phenolic and flavonoid content present in 6.5% (w/v) honey solutions was increased, improving the antioxidant activity of this system.

Relationship between the elemental composition of grapeyards and bioactive compounds in the Cabernet Sauvignon grapes Vitis vinífera harvested in Mexico

The red grape Vitis vinífera is an important source of phenolic compounds, which can prevent disease if included as a part of a diet. The levels of these compounds in grapes have been associated with various environmental factors, such as climate, soil composition, and biotic stress. The purpose of this study was to determine the relationship between the elemental compositions of the soil and the grapes and the presence of bioactive compounds, such as catechin, epicatechin, piceid and resveratrol. Ethanol-based extracts of red grapes were used to quantify total and individual phenolic compounds by HPLC. It was observed that the elemental compositions of the soil and the grapes were related to their locations within different wine-producing regions. A principal component analysis showed a relationship between high metal content (Sr, Mn, Si and Pb) and higher concentrations of antioxidants in the grapes.

Phenolic compounds in juices of apple cultivars and their relation to antioxidant activity

Apples and their juices are important sources of phenolic compounds in human diet. Using the same juice processing method, we compared phenolic composition as well as antioxidant activity of juices from various table apple cultivars, grown at the same location. Antioxidant activity of apple juices was estimated by application of two assays, ABTS cation radical decolorization and by scavenging of reactive oxygen species (ROS) generated by xanthine/xanthine oxidase (O 2 · - , H 2 O 2 , OH · ; superoxide assisted Fenton reaction), as measured by inhibition of ethylene release from KMB (α-Keto-γ-(methylthio)butyric acid). The apple juices differed in phenolic content and antioxidant activity, where cultivar differences were more relevant than environmental factors. Furthermore, to improve antioxidant performance in the XOD-test, a juice low in phenol content was supplemented with the appropriate amounts of phenols to the level of the best juice indicating that these phenolics contribute to the antioxidant activity of the apple juice. In ac­cordance to literature, the phenolic compounds re­presenting the main anti­oxidant activity in the apple juices comprise flavan-3-ols and chlorogenic acid.

Phenolic amides (avenanthramides) in oats - a review

Whole grain cereals such as oats are important sources of phenolic compounds. Oats contain phenolic amides, also named avenanthramides (AVAs), which have beneficial health properties because of their antioxidant, anti-inflammatory, and antiproliferative effects. The most common avenanthramides are esters of 5-hydroxyanthranilic acid with p-coumaric (AVA-A), ferulic (AVA-B), or caffeic (AVA-C) acids. The studies related to the stability of AVAs showed that AVA-B is sensitive to alkaline and neutral conditions and this sensitivity increases with higher temperatures. However, has been reported that AVA-A and AVA -C are more stable under the same conditions (alkaline and neutral conditions), and in addition that AVAs content of oats is increasing significantly with the germination process. AVAs help in preventing free radicals from damaging LDL cholesterol while AVAs-enriched extract of oats combined with vitamin C synergistically inhibited LDL oxidation in vitro. Both animal studies and human clinical trials confirmed that oats antioxidants have the potential of reducing cardiovascular risks by lowering serum cholesterol and inhibiting LDL oxidation and peroxidation. Therefore, the consumption of oats and products thereof is extremely important in reducing the risk of cardiovascular diseases.

Antioxidant and antimicrobial activity of natural phenolic extract from defatted soybean flour by‐product for stone fruit postharvest application

Fresh fruit is highly perishable during storage and transport, so there has been growing interest in finding safe and natural antimicrobial compounds as a control tool. Phenolic compounds are secondary metabolites naturally present in vegetable material and have been associated with antimicrobial and antioxidant properties. Therefore, the aim of this study was to investigate the antioxidant capacity and potential antimicrobial effect of phenolic extract obtained from defatted soybean flour against selected pathogenic bacteria and microorganisms responsible of fruit decay. Analysis of phenolic composition by HPLC-MS showed the presence of a wide range of compounds, with isoflavones and phenolic acids the main polyphenols identified. Furthermore, the phenolic extract had important antioxidant activity by two different assays. Related to antimicrobial activity, in vitro experiments demonstrated that phenolic extract displayed a high activity against the main foodborne pathogens, while a moderate inhibition was found against five spoilage yeasts and Monilia laxa and a scarce effect for Penicillium glabrum, Cladosporium uredinicola and Botrytis cinerea. Interestingly these compounds considerably inhibited the mycelial growth of Monilia laxa, in both in vitro and in vivo experiments. The results of the present study revealed that defatted soybean flour is an important source of phenolic compounds with remarkable antimicrobial and antioxidant activity, suggesting the possibility of using them as natural additives in postharvest treatments to extend the shelf life of fruit.

Effect of a Purified Extract of Olive Mill Waste water on Endothelial Cell Proliferation, Apoptosis, Migration and Capillary-Like Structure in vitro and in vivo

Olive oil, a major feature of the Mediterranean diet, is an important source of phenolic compounds. Poliphenols are associated with inhibition of several pathological processes, including cancer. Soluble phenols are contained in the aqueous part of olive and are discarded during oil production in the ‘olive mill wastewaters’. Here we investigated the properties of a purified extract of olive mill wastewaters, named A009, as potential anti-angiogenic compound. While the strong anti-oxidant activity of olive derived phenolic compounds has been well characterized, little is known about their anti-angiogenic properties. We investigated effects of A009 on endothelial cell morphogenesis, proliferation, migration and apoptosis, comparing the results obtained with the activity of a well-characterized olive oil phenol, Hydroxytyrosol (HT). Further, we tested the effects of A009 and HT in an in vivo angiogenesis assay. We found that A009 exerted strong anti-angiogenic effects both in vitro and in vivo, and that the complex natural purified extract has stronger anti-angiogenic potential when compared to the same concentrations of HT in most of the assays performed. These data demonstrate that a novel purified, phenols enriched, extract with anti-angiogenic, and angiopreventive potential can be obtained from olive oil mill waste material, recovering useful products from an agricultural waste.

Effect of ethanolic flax (Linum usitatissimum L.) extracts on lipid oxidation and changes in nutritive value of frozen-stored meat products.

Flaxseed (Linum usitatissimum L.) is an important source of phenolic compounds, mainly lignans. Antioxidant capacities of flaxseed extracts that contain the compounds have been reported earlier. However, there is a lack of accessible information about their activity against lipid oxidation in meat products. Therefore, the effect of ethanolic flaxseed extracts (EFEs) on lipid stability and changes in nutritive value of frozen-stored meat products (pork meatballs and burgers) was determined. EFEs from three Polish flax varieties (Szafir, Oliwin, Jantarol) were applied in the study. During 150-day storage of meat products, the lipid oxidation (peroxide and TBARS value) and thiamine retention were periodically monitored, alongside with methionine and lysine availability and protein digestibility. The addition of EFEs significantly limited lipid oxidation in stored meatballs and burgers. EFE from brown seeds of Szafir var. was superior to the others from golden seeds of Jantarol and Oliwin. Moreover, the extracts reduced changes in thiamine and available lysine content, as well as protein digestibility, during storage time. The effect of EFE addition on available methionine retention was limited. The ethanolic flaxseed extracts exhibit antioxidant activity during frozen storage of meat products. They can be utilized to prolong shelf-life of the products by protecting them against lipid oxidation and deterioration of their nutritional quality. However, antioxidant efficiency of the extracts seems to depend on chemical composition of raw material (flax variety). Further investigations should be carried on to explain the issue.

The important role of quinic acid in the formation of phenolic compounds from pyrolysis of chlorogenic acid

Chlorogenic acid and its two structural components, quinic acid and caffeic acid, were pyrolyzed under reaction conditions simulating the typical pyrolysis conditions inside a burning cigarette. Major phenolic products from pyrolysis of the three acids were quantified and compared to evaluate the respective contribution of the quinic and caffeic acid moieties to the overall phenolic yield in chlorogenic acid pyrolysis. The results show that the most prominent phenolic product of chlorogenic acid is catechol, followed in order by phenol, hydroquinone, and alkylcatechols. Among these phenolics, catechol and alkylcatechols are formed mainly from the caffeic acid moiety of chlorogenic acid, while phenol and hydroquinone are produced predominantly from the quinic acid moiety. The quinic acid moiety can thus contribute more than 40 % of the overall phenolic yields in chlorogenic acid pyrolysis (0.54 mol mol−1 chlorogenic acid pyrolyzed at 600 °C). Because considerable amounts of free quinic acid and its derivatives exist in tobacco, the results of this study indicate that quinic acid can be an important source of phenolic compounds, especially hydroquinone and phenol, in tobacco smoke.

Synthesis of Biscardanol as Key Intermediary in Preparation of Bistioxanthones

The cashew nut shell liquid (CNSL) is an important source of phenolic compounds such as anacardic acids, cardols and cardanols. These compounds present many biological activities. The components of CNSL were isolated and purified by column chromatography. Cardanol was employed as starting material for a methathesis reaction making use of Grubbs 1 st generation catalyst, under nitrogen atmosphere, in dichloromethane, heating at 50 o C and, magnetic stirring during 98 h. The product biscardanol is a key-intermediate for the synthesis of new bis thioxanthones.

Changes in the microstructure and location of some bioactive compounds in persimmons treated by high hydrostatic pressure

Persimmon fruit are an important source of phenolic compounds, dietary fibre, and carotenoids. However, the location of these elements in the tissue is directly connected with processing techniques used. The aim of this work was to study the effect of high hydrostatic pressure (HHP) on the microstructure of persimmon fruit cv. ‘Rojo Brillante’ during different ripening stages and the relationship of this treatment with changes in the location of some bioactive compounds. Samples from persimmon fruit cv. ‘Rojo Brillante’ from two ripening stages, with and without deastringency treatment (95–98% CO 2), were treated by HHP at 200 and 400 MPa during 1, 3, and 6 min. A microstructural study using cryo-scanning electron microscopy, light microscopy, and confocal laser scanning microscopy (Cryo-SEM, LM, and CLSM) was carried out. Total soluble solid (TSS) content and some textural properties were also analyzed. The microstructural study showed that application of HHP caused cell wall disruption and intracellular component dispersion throughout the tissue, together with some nutritionally interesting compounds (tannins, fibres, and carotenoids). TSS content diminished in astringent samples when HHP was applied. This was attributed to precipitation of soluble tannins, which are responsible for fruit astringency. Therefore, it might be possible to omit a deastringency treatment with CO 2 before HHP treatments. HHP treatments caused an overall decrease in firmness for both ripening stages and an increase in cohesiveness (TPA analysis) in the more advanced stage.

Protective effects of Syzygium cumini seed extract against methylmercury-induced sistemic toxicity in neonatal rats

Syzygium cumini (L.) Skeels (Sc) belongs to the medicinal plants with an important source of phenolic compounds. Sc has been shown to possess antioxidant and anti-inflammatory properties. Methylmercury (MeHg), a highly toxic environmental pollutant, induces oxidative stress and dysfunction in many cell types. This study was aimed to evaluate the effect of aqueous seed extract of Sc (ASc) on MeHg-induced toxicity in rats. Two-day-old rats (P2) received a single dose of MeHg (10mg/kg) and two doses of ASc (0.9mg/kg) per os. After two days, the effects of the treatment were investigated in the cerebral cortex, hippocampus, kidney, liver and urine samples. Our results demonstrated that N-acetyl-β-D: -glucosaminidase (NAG) activity in the kidney and urine, the lipid peroxidation levels in the liver and kidney samples, as well as the adenosine deaminase (ADA) activity in the hippocampus, kidney and liver were higher in MeHg-group when compared to the control group. The administration of ASc reverted the toxic effects of MeHg. It is noteworthy to observe that the main compounds present in the ASc, as gallic acid (the major component), chlorogenic acid and rutin, might be the responsible for such benefit, since they were found to display antioxidant properties.

PHYSICOCHEMICAL CHARACTERIZATION OF THE ORANGE JUICE WASTE WATER OF A CITRUS BY-PRODUCT

Large quantities of wastes are produced during the industrial transformation of citrus fruit, and these constitute a serious problem. However, instead of disposing of them, they can be used to obtain by-products rich in bioactive compounds. One such by-product is the orange juice waste water generated in the process of obtaining citrus fiber. The aim of this study was to characterize the physicochemical and microbiological properties of the orange juice waste water of a citrus by-product by determining the pH, soluble solids, color, reduction of residual nitrite and total antioxidant activity, along with the content of phenolic compounds, organic acids and sugars. The orange juice waste water decreases the nitrite levels and shows a high capacity to reduce the formation of free radicals. Narirutin and hesperidin were the most concentrated phenolic compounds, whereas the main sugar was glucose. Five organic acids were identified, the main one being succinic acid. PRACTICAL APPLICATIONS The orange juice waste water can be suitable for applications on the food industry. It is an important source of phenolic compounds in which antioxidant properties could be very appreciated in a big number of food processing to avoid its oxidation during processing but also during storage period. Another important effect of orange juice waste water is the reduction of residual nitrite level in foods in which the nitrite is added as an additive, for example, in meat products industry; the reduction of residual nitrite level could reduce the possibility to nitrosamine formation. One other important reason for their suitability is their natural origin, which consumers find comforting and which is beneficial for the environment.

Bioactive Compounds of Selected Fruit Juices

Fruits are one of the most important sources of phenolic compounds in our diet. Many of these compounds exhibit a wide range of biological activities, especially antioxidant activity. The objective of this study was to determine the composition and antioxidant activity of phenolic compounds found in fruit juice obtained from buckthorn, flowering quince, rowanberry and hawthorn. Hydroxycinnamic acids (neochlorogenic and chlorogenic acid) and procyanidins were the main phenolics in rowanberry juice. The highest level of flavonols (quercetin derivatives) was found in sea buckthorn. All juices showed strong free-radical scavenging activity against ABTS*+ radicals and ferric reducing ability measured by the FRAP method. The strongest antioxidant activity was found in rowanberry juice, but the lowest was measured in hawthorn and sea buckthorn juices.

Radical-Scavenging Activity of Orsellinates

Lichens are an important source of phenolic compounds and have been intensively investigated for their biological and pharmacological activities. Lecanoric acid (1), a lichen depside, was isolated from a Parmotrema tinctorum specimen and treated with alcohols to produce orsellinic acid (2) and orsellinates (3) to (9) (2,4-dihydroxy-6-n-methyl benzoates). Free radical scavenging activity of methyl (3), ethyl (4), n-propyl (5), n-butyl (6), iso-propyl (7), sec-butyl (8), tert-butyl (9) orsellinates was evaluated using 2,2'-diphenyl-1-picrylhydrazyl (DPPH) method. Results showed that chain elongation of methyl (3) to n-butyl (6) causes a rise in the antioxidant activity. However, iso-propyl (7) and tert-butyl (9) were more active than the correspondent linear compounds, although sec-butyl (8) was less active among the chain ramified compounds. All the orsellinates were less active than lecanoric acid (1) and orsellinic acid (2). Orcinol (10) and resorcinol (11) were also determined for comparison with activities of orsellinates. Gallic acid (12) was used as control.