Extraction and analysis of phenolics in food

Naczk, M.; Shahidi, Fereidoon

doi:10.1016/j.chroma.2004.08.059

Cited by 700 publications

(427 citation statements)

References 194 publications

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“…Phenolic-enriched extracts of the dried pulverised leaves (20 g) were prepared by simultaneous extraction and fractionation with a mixture of acidified acetone water (140 ml acetone, 60 ml water and 0.2 ml HCl (Naczk and Shahidi, 2004) and n-hexane (200 ml) for 24 h to obtain two phases. The lower phase of phenolic-enriched fraction referred to as the crude extract was separated from the upper phase of terpenoid-enriched n-hexane fraction Folin-Ciocalteau phenol reagent was used to determine total phenolic constituents of the crude extracts as described by Makkar (2003).…”

Section: Preparation Of Extractsmentioning

confidence: 99%

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

Ahmed

McGaw

Elgorashi

et al. 2014

Journal of Ethnopharmacology

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Graphical abstractPhenolic-enriched extracts of four Combretum species namely Combretum bracteosum, Combretum padoides, Combretum vendae and Combretum woodii used in South African traditional medicine to treat various ranges diseases were evaluated against some diarrhoeal aetiologies. All the crude extracts and their fractions of varied polarities had good antimicrobial (non-polar fractions) or good antioxidant (polar fractions) activity. The crude extract of all the plant species were cytotoxic to Vero cell lines but did not lead to COX enzyme inhibition. Phenolic-enriched extractsFour Combretum species traditionally used for treating infectious and gastrointestinal complications in southern Africa In vitro assays: antioxidant, anti-inflammation, antimicrobial, cytotoxicity AbstractEthnopharmacological importance: Infections and gastrointestinal (GIT) disorders such as diarrhoea causes many problems in human health and animal production. Many Combretum species are used in traditional medicine to treat various diseases by rural people in Africa and Asia. Much of the work done to date on some species to validate their ethnopharmacological use was on the non-polar or intermediate polarity components. Many species are yet to be studied against relevant disease parameters using more polar extracts. Aims:The polar components were extracted and fractionated by solvent-solvent fractionation to yield fractions of different polarities. The activity of these fractions on different parameters that could be involved in infectious and gastrointestinal track (GIT) disorders was investigated. The cytotoxic activities of the extracts were also determined to evaluate the potential of these extracts to combat diarrhoea in production animals. Materials and Methods:Phenolic-enriched leaf extracts of Combretum bracteosum (Cob), Combretum padoides (Cop), Combretum vendae (Cov) and Combretum woodii (Cow) were obtained by extracting with a mixture of 70% acetone acidified with 1% HCl and n-hexane. The extract was sequentially treated by solvent-solvent fractionation with dichloromethane, ethyl acetate, and butanol to yield fractions with a large variation in polarity. The phenolic constituents of the extracts and fractions were determined using standard procedures. The antioxidant activities were determined using various standard methods. The minimum inhibitory concentrations (MICs) of the crude extracts and fractions against four bacterial and three fungal strains were assessed with a microplate serial dilution method.Cyclooxygenase (COX) and lipoxygenase (LOX) enzyme inhibitory assays and cytotoxicity studies against Vero cells were also carried out.Result: Some of the fractions had much higher antioxidant activity than the positive controls. The average EC 50 values of the extracts for the DPPH and ABTS antioxidant assays were 0.21-12 µg/ml (Cop), 0.25-16 µg/ml (Cov), 0.33-9.41 µg/ml (Cow) and 4.97-85 µg/ml (Cob) respectively while the mean EC 50 values for the positive controls ascorbic acid and trolox were 1.28-1.51 and 1.02-1.19 ...

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Section: Preparation Of Extractsmentioning

confidence: 99%

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

Ahmed

McGaw

Elgorashi

et al. 2014

Journal of Ethnopharmacology

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“…Total phenolics in shoot tip of Leucaena leucocephala grown in Thailand were 405 and 60.6 mg/100 g dry matter, respectively (Chanwitheesuk et al 2005). Phenolics are distributed non-uniformly at the tissue, cellular and subcellular levels (Naczk and Shahidi 2004). The result suggested that chloroform used for chlorophyll removal might remove some phenolic compounds, especially those with low polarity.…”

Section: Effect Of Prior Chlorophyll Removal On Yield Compositions Amentioning

confidence: 99%

Antioxidant activities of lead (Leucaena leucocephala) seed as affected by extraction solvent, prior dechlorophyllisation and drying methods

et al. 2012

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Extracts of brown lead (Leucaena leucocephala) seed prepared using different extraction solvents were determined for antioxidative activities using different assays. The highest yield (3.4-4.0%) was obtained when water was used as an extraction solvent, compared with all ethanolic extracts used (1.2-2.0 %) (P<0.05). Much lower chlorophyll content was found in the water extract. When hot water was used, the resulting extract contained lower total phenolic and mimosine contents (P<0.05). In general, 60-80 % ethanolic extracts had higher 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, ferric reducing antioxidant power (FRAP) and metal chelating activity than water extracts (P<0.05). When brown lead seed was dechlorophyllised prior to extraction, the water extract had slightly increased yield with lower chlorophyll content. Nevertheless, prior chlorophyll removal resulted in the increase in antioxidative activities but lower total phenolic and mimosine contents (P<0.05). Generally, phenolic compounds and mimosine were more released when water was used as the extraction solvent, while the lower amount of chlorophyll was extracted. Oven-drying exhibited the negative effect on antioxidative activities and mimosine content. The higher antioxidative activities with concomitant higher total phenolic and mimosine contents were found in water extract dried by freeze drying. Thus, extraction solvent, dechlorophyllisation and drying methods directly influenced the yield and antioxidative activity of lead seed extract.

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“…However, longer extraction time increases the chance of oxidation of phenolics unless reducing agents are added to the solvent system [28]. Extraction process was carried out under the condition of different extraction times from 10 to 50 min, while other extraction condition was as follows: a ratio of solid/liquid (g/mL) (3:40), ethanol concentrations 70%, the temperature of the water bath 508C by microwaveassisted.…”

Section: Effect Of Different Time On Extraction Rate Of Polyphenolsmentioning

confidence: 99%

Optimum extraction Process of polyphenols from the bark of Phyllanthus emblica L. based on the response surface methodology

Yang

Jiang²,

et al. 2009

J of Separation Science

155

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Original PaperOptimum extraction Process of polyphenols from the bark of Phyllanthus emblica L. based on the response surface methodology Phyllanthus emblica L. is an economic plant used in Chinese medicine for the treatment of various diseases. The bark of P. emblica is rich in polyphenols and its extractions have shown strong antioxidative and radical scavenging activity. Response surface methodology (RSM) was used to assess the optimal extraction of polyphenols from P. emblica bark. Various extraction parameters including ethanol concentration, extraction time, temperature, solid -liquid ratio, and extraction times were chosen to identify their effects on polyphenols extraction. Among these parameters, extraction times and solvent concentration were found to have significant effect on polyphenols extraction. RSM was applied to obtain the optimal combination of solvent concentration, extraction time, temperature, and extraction time for maximum rate of extraction. The most suitable condition for the extraction of polyphenols was at ethanol concentration 75%, extraction time 25 min, extraction temperature 458C, and extraction times 3. At these optimal extraction parameters, the maximum extraction of polyphenols obtained experimentally was found to be very close to its predicted value. The extraction rate of polyphenols was 19.78% at the optimum conditions. The mathematical model developed was found to fit with the experimental data of polyphenols extraction.

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Extraction and analysis of phenolics in food

Cited by 700 publications

References 194 publications

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

Polarity of extracts and fractions of four Combretum (Combretaceae) species used to treat infections and gastrointestinal disorders in southern African traditional medicine has a major effect on different relevant in vitro activities

Antioxidant activities of lead (Leucaena leucocephala) seed as affected by extraction solvent, prior dechlorophyllisation and drying methods

Optimum extraction Process of polyphenols from the bark of Phyllanthus emblica L. based on the response surface methodology

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