Antioxidant activity of tea theaflavins and methylated catechins in canola oil

Su, Ya‐Lun; Xu, Jinze; Ng, Chi‐Fai; Leung, Lai K.; Huang, Yü; Chen, Zhenyu

doi:10.1007/s11746-004-0894-7

Cited by 29 publications

(23 citation statements)

References 17 publications

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“…Although the structure‐antioxidant activity relationship of flavonoids has been well defined in hydrophilic systems , studies dealing with this in hydrophobic systems are scarce. Free flavonoids, mainly quercetin, myricetin, morin, (+)catechin, (−)epigallocatechin, (−)epicatechin, and kaempferol, have been incorporated in different lipid systems with varying degrees of success in terms of oxidative stability, such as methyl linoleate , canola oil , cottonseed oil , corn oil , or fish oil . The antioxidant activity found in methyl linoleate and purified sunflower oil was related to the number of phenolic hydroxyl groups, 2,3 double bond in the C‐ring and a glycoside moiety in the molecule .…”

Section: Introductionmentioning

confidence: 99%

Design of flavonoid microparticles with channel forming properties to improve oxidative stability of sunflower oil

Morelo¹,

Márquez‐Ruiz

Holgado

et al. 2017

Euro J Lipid Sci & Tech

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Quercetin (Q) and epicatechin (E) microparticles were designed using an oil‐insoluble polymer (inulin [In]) as encapsulating agent and with or without an oil‐soluble polymer (soy protein isolate [SPI]) by spray‐drying. Encapsulation efficiencies were significantly higher for the E systems than for Q systems, suggesting that the spatial arrangement may affect the hydroxyl groups availability to form hydrogen bonds. The microencapsulated flavonoids were added to sunflower oil (SO) in order to evaluate its oxidative stability. The induction period (IP) of SO, determined in Rancimat at 60°C, significantly increased when Q‐microparticles with or without SPI were added, showing those with SPI the highest IP value. In the case of E systems, the IP of SO increased only when E–In microparticles with SPI were added. These results suggest that SPI may favor the diffusion of flavonoids to the lipid medium by the formation of channels into the microparticles. The channels formation was observed for Q–In–SPI and E–In–SPI by a confocal laser scanning microscopy study. Additional oxidation studies under conditions of lower oxygen availability resulted in overall more retarded oxidation and no clear effect of SPI incorporation was observed. Practical application: The results show that it is possible to design flavonoid microparticles with antioxidant activity in bulk oils. The inclusion of a lipid‐soluble polymer such as soy protein isolate in the microparticles favors the flavonoid release from the microparticles to bulk oil by channel formation. Epicatechin (E) and quercetin (Q) microparticles designed with inulin (IN, encapsulating agent) and soy protein isolate (SPI, channelizing agent) are incorporated to sunflower oil (SO). The channels formation is observed for Q–In–SPI and E–In–SPI by confocal laser scanning microscopy. The induction period (IP) of SO (Rancimat at 60°C) significantly increases when Q‐microparticles with or without SPI are added, showing those with SPI the highest IP value. Regarding E systems, the IP of SO increases only when E–In microparticles with SPI are added. No clear effect of SPI incorporation is observed in additional oxidation studies under conditions of lower oxygen availability.

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Section: Introductionmentioning

confidence: 99%

Design of flavonoid microparticles with channel forming properties to improve oxidative stability of sunflower oil

Morelo¹,

Márquez‐Ruiz

Holgado

et al. 2017

Euro J Lipid Sci & Tech

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“…86 Similarly, O-methylation at position C-3 0 in (À)-epicatechin, (À)-epigallocatechin and (À)-epicatechin-3-O-gallate elicited a potential inhibition of lipid oxidation of canola oil in comparison to the aglycone. 87 In a recent study, C-3 0 and C-4 0 -O-methyl ethers of (+)-catechin and (À)-epicatechin showed a lower antioxidant capacity than the parent compound, as measured by the ferric-reducing power (FRAP) and by the ability to scavenge the ABTS + radical cation.…”

mentioning

confidence: 99%

Insights into the metabolism and microbial biotransformation of dietary flavan-3-ols and the bioactivity of their metabolites

et al. 2010

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Flavan-3-ols, occurring in monomeric, as well as in oligomeric and polymeric forms (also known as condensed tannins or proanthocyanidins), are among the most abundant and bioactive dietary polyphenols, but their in vivo health effects in humans may be limited because of their recognition as xenobiotics. Bioavailability of flavan-3-ols is largely influenced by their degree of polymerization; while monomers are readily absorbed in the small intestine, oligomers and polymers need to be biotransformed by the colonic microbiota before absorption. Therefore, phenolic metabolites, rather than the original high molecular weight compounds found in foods, may be responsible for the health effects derived from flavan-3-ol consumption. Flavan-3-ol phenolic metabolites differ in structure, amount and excretion site. Phase II or tissular metabolites derived from the small intestine and hepatic metabolism are presented as conjugated derivatives (glucuronic acid or sulfate esters, methyl ether, or their combined forms) of monomeric flavan-3-ols and are preferentially eliminated in the bile, whereas microbial metabolites are rather simple conjugated lactones and phenolic acids that are largely excreted in urine. Although the colon is seen as an important organ for the metabolism of flavan-3-ols, the microbial catabolic pathways of these compounds are still under consideration, partly due to the lack of identification of bacteria with such capacity. Studies performed with synthesized or isolated phase II conjugated metabolites have revealed that they could have an effect beyond their antioxidant properties, by interacting with signalling pathways implicated in important processes involved in the development of diseases, among other bioactivities. However, the biological properties of microbederived metabolites in their actual conjugated forms remain largely unknown. Currently, there is an increasing interest in their effects on intestinal infections, inflammatory intestinal diseases and overall gut health. The present review will give an insight into the metabolism and microbial biotransformation of flavan-3-ols, including tentative catabolic pathways and aspects related to the identification of bacteria with the ability to catabolize these kinds of polyphenols. Also, the in vitro bioactivities of phase II and microbial phenolic metabolites will be covered in detail.

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“…Since the hydroxyl substitutions play an important role in antioxidative activity, the level of antioxidative activity appeared related to the number of them, and we previously reported a similar trait on radical-scavenging activity (Tabata et al, 2008). It has also been noted that methylated derivatives of catechines have a lower protective activity against lipid oxidation than their corresponding precursors (Su et al, 2004). Since the physiological concentration of phenolic compounds is less than a few lM, our results suggest that the M. japonicus leaf antioxidative component of mallotinic acid, mallotusinic acid, corilagin, and geraniin can protect intracellular and extracellular components against oxidative stress under the physiological conditions.…”

Section: Discussionmentioning

confidence: 73%

Protective activity of components of an edible plant, Mallotus japonicus, against oxidative modification of proteins and lipids

Tabata¹,

Katšube²,

Moriya³

et al. 2010

Food Chemistry

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Antioxidant activity of tea theaflavins and methylated catechins in canola oil

Cited by 29 publications

References 17 publications

Design of flavonoid microparticles with channel forming properties to improve oxidative stability of sunflower oil

Design of flavonoid microparticles with channel forming properties to improve oxidative stability of sunflower oil

Insights into the metabolism and microbial biotransformation of dietary flavan-3-ols and the bioactivity of their metabolites

Protective activity of components of an edible plant, Mallotus japonicus, against oxidative modification of proteins and lipids

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