Food & Function Blog

Researchers from France have described a new method of combining an in vitro digestion method with a Caco 2 cell model to study lipid digestion, absorption and conversion to lipid bodies and used this to study the influence of the structure of dietary lipid sources during digestion.

Until recently, studies on dietary fats only considered the impact of their global intake and their total fatty acid composition, not  their structure in foods. By understanding the intake and absorption of dietary oils, diseases such as obesity, diabetes and atherosclerosis (which are characterised by a high fat diet) can be better understood.

In this work, four emulsions based on  milk fat olein (OL) or rapeseed oil (RA) as the dispersed phase and either lecithin or sodium caseinate as the emulsifier were examined. It was demonstrated that in vitro digestion fluids resulting from food emulsions could be used to incubate on Caco-2 cells as a new model for testing emulsion digestion and absorption. It was also shown that the emulsion composition influenced the activation of lipid metabolism and TAG secretion.

To read the full article, click the link below. Read it for free until 23rd March.

Coupling in vitro gastrointestinal lipolysis and Caco-2 cell cultures for testing the absorption of different food emulsions, Cecile Vors, Perrine Capolino, Clemence Guerin, Emmanuelle Meugnier, Sandra Pesenti, Marie-Agnes Chauvin, Julien Monteil, Noel Peretti, Maud Cansell, Frederic Carriere and Marie-Caroline Michalski, Food Funct., 2012, DOI: 10.1039/c2fo10248j

You may also be interested in this review article which is free to access

Review of in vitro digestion models for rapid screening of emulsion-based systems
David Julian McClements and Yan Li
Food Funct., 2010, 1, 32-59, DOI: 10.1039/C0FO00111B

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Scientists in Australia and China have investigated the effects of dietary nitrate intake on nitric oxide (NO) status. NO is important for the control of vasodilation and blood pressure and it can be obtained from the arginine/NOS pathway in cells, but also via nitrates in foods such as spinach and cabbage.

The mechanism of nitrate intake in the mouth is important because about 25% of dietary nitrate is secreted into saliva, of which approximately 20% (5% of the ingested intake) is converted to nitrite in the mouth by bacteria on the tongue. The nitrite is swallowed and is converted to NO in the acidic environment of the stomach or is absorbed and further reduced to NO in the body through a number of mechanisms. This pathway can be interrupted by spitting and not swallowing the nitrite-rich saliva or by the use of antibacterial mouth wash; it is unknown whether the use of antibacterial toothpaste interrupts the pathway.

In this study, the dose–response of dietary nitrate on both NO status and nitrate reduction in the mouth was assessed. It was found that increasing nitrate intake results in a linear dose-related increase in nitric oxide status and nitrate reduction in the mouth. It was also found that the use of antibacterial toothpaste does not inhibit nitrate reduction.

To read the article in full, click the link below: it’s free to access until 20th March.

Nitrate causes a dose-dependent augmentation of nitric oxide status in healthy women, Catherine P. Bondonno, Kevin D. Croft, Ian B. Puddey, Michael J. Considine, Xingbin Yang, Natalie C. Ward and Jonathan M. Hodgson, Food Funct., 2012, DOI: 10.1039/c2fo10206d

You may also be interested in this article which is also free to access:

Dealcoholized red wine reverse vascular remodeling in an experimental model of metabolic syndrome: role of NAD(P)H oxidase and eNOS activity
Marcela Alejandra Vazquez-Prieto ,  Nicolás Federico Renna ,  Carina Lembo ,  Emiliano Raúl Diez and Roberto Miguel Miatello, Food Funct., 2010, 1, 124-129, DOI: 10.1039/C0FO00077A

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Ana Martinez and colleagues from Mexico have reported a theoretical study on the antioxidant mechanism of xanthones. Xanthones are bioactive compounds found in tropical fruits such as mangosteen (Garcinia mangostana) and have shown antioxidant behaviour in a number of experimental studies, however the mechanism of action is not thoroughly understood.

In this work, the antioxidant properties of 20 xanthones and 8 xanthone anions were studied and the more efficient free radical scavengers were identified using a theoretical approach based on single electron transfer (SET). The quantum chemical calculations showed that the reaction between xanthones and OH radicals is thermodynamically unfavourable, however the reaction between xanthone anions (which are present under physiological conditions) and OH radicals is exergonic, and so xanthone anions behave as antioxidants by deactivating the OH free radical species. Understanding the free-radical scavenging mechanisms of these compounds may help combat degenerative diseases such as Alzheimer’s disease which are linked to the antioxidant mechanistic pathway.

Read the article in full by clicking the link below. It’s free to access until March 13th!

Xanthones as antioxidants: a theoretical study on the thermodynamics and kinetics of the single electron transfer mechanism, A. Martínez, E. Hernández-Marin and A. Galano, Food Funct., 2012, DOI: 10.1039/C2FO10229C

 You may also be interested in the following article which is free to acces.

Dietary chromones as antioxidant agents—the structural variable, M. M. Dias,  N. F. L. Machado and M. P. M. Marques, Food Funct., 2011, 2, 595-602, DOI: 10.1039/C1FO10098J

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A study recently published in Food & Function from Advisory Board member Junji Terao and co-workers in Japan shows that water-dispersible hesperetin, an aglycone of citrus flavonoids, is effectively accumulated in human plasma and works as a vasodilator through its metabolites.  The study concludes that hesperetin is a promising flavonoid as a component of functional foods and can be expected to help in maintaining vascular health.

Hesperetin is the aglycone of hesperidin which is present in citrus fruits and has been implicated in many of their beneficial effects including vascular protection; hesperetin has better bioavailability than hesperidin.  Previous work implies that elevation of water solubility results in even higher bioavailability of hesperetin, which has low aqueous solubility due to its hydrophobic flavanone structure. Therefore, in this study micronized water-diseprsable hesperetin was developed and its bioavailability and effects on vasodilation-related functions tested in vitro and in vivo.

Water-dispersible hesperetin, as compared to intact hesperetin, was absorbed into the blood rapidly and at high concentrations.  LC-MS analysis identified a range of metabolites and one, Hp7GA was shown, in cultured endothelial cells, to enhance NO release by inhibiting NADPH oxidase activity.  Furthermore, a volunteer study using women with cold sensitivity showed that a single dose was effective on peripheral vasodilation.  The results of this study suggest that hesperetin is able to exert potential vasodilation effects by the endothelial action of its plasma metabolites. 

Interested in knowing more?  Read the full article for free until March 9th.

Bioavailability of orally administered water-dispersible hesperetin and its effect on peripheral vasodilatation in human subjects: implication of endothelial functions of plasma conjugated metabolites
Hiroko Takumi, Hiroyasu Nakamura, Terumi Simizu, Ryoko Harada, Takashi Kometani, Tomonori Nadamoto, Rie Mukai, Kaeko Murota, Yoshichika Kawai and Junji Terao
Food Funct., 2012, Advance Article, DOI: 10.1039/C2FO10224B

You may also be interested in this review from Professor Terao which is free to access.

Conjugated quercetin glucuronides as bioactive metabolites and precursors of aglycone in vivo
Junji Terao, Kaeko Murota and Yoshichika Kawai
Food Funct., 2011, 2, 11-17, DOI: 10.1039/C0FO00106F

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