Archive for November, 2010

Emulsion-based delivery systems: reviewing digestion models and interfacial design

Issues 1 and 2 of Food & Function are now here, and the vision of pulling together high impact chemical and physical research and linking it to human health and nutrition is starting to be fulfilled. 

This week on the blog we are highlighting reviews published from the physics community.

Review of in vitro digestion models for rapid screening of emulsion-based systems In Issue 1 ‘Review of in vitro digestion models for rapid screening of emulsion-based systems’ by David Julian McClements and Yan Li looks at the current status of in vitro digestion models for simulating lipid digestion.  Emulsion-based delivery systems are being developed to encapsulate, protect, and release non-polar lipids, vitamins, nutraceuticals and drugs.  There is, therefore, of increasing interest in the food and pharmaceutical industries to understand and control the digestion of these emulsified lipids.  To do this, in vitro digestion models which simulate the human gastrointestinal tract are needed to test the efficacy of different approaches for controlling lipid digestion.

 

As a continuation, Issue two contains a review which covers the physico-chemical changes occurring in emulsion based delivery systems during gastric and small intestine digestion.  In ‘Interfacial design of protein-stabilized emulsions for optimal delivery of nutrients’ by Amir Malaki Nik, Amanda J. Wright and Milena Corredig protein-stabilised oil-in-water emulsions are focused on.  Proteins are often used as ingredients in food emulsions, as their amphiphilic structures provide electrostatic and steric stabilisation. A better understanding of how to tailor the composition of oil droplet surfaces in food emulsions will aid in optimizing lipid digestion and, as a result, delivery of lipophilic nutrients. Interfacial design of protein-stabilized emulsions for optimal delivery of nutrients

Interested in reading more? Follow the links below:

Review of in vitro digestion models for rapid screening of emulsion-based systems

Interfacial design of protein-stabilized emulsions for optimal delivery of nutrients

You may also want to submit a review or an article linking the physics of food with health and nutrition.

Manuscripts can be submitted online here 

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The medicine’s in the (wine) bottle

Some red wines contain such high levels of polyphenols that a single glass has equivalent bioactivity to several daily doses of an anti-diabetes drug, say Austrian scientists. 

Polyphenols play a key role in the health benefits of wine by acting as antioxidants that prevent cell damage, but the other possible effects of these chemicals are not yet fully understood. Now, a group led by Alois Jungbauer from the University of Natural Resources and Life Sciences, Vienna, Austria, have shed light on this area by examining polyphenols in eight Austrian red wines. They assessed polyphenol activity towards a receptor called PPAR-gamma (peroxisome proliferator-activated receptor gamma). This receptor is present in many tissues in the body, and is primarily involved in the development of fat cells, in energy storage, and in modifying lipid and glucose levels in the blood, making it a key target for drugs for cardiovascular and metabolic diseases. 

Red wines are rich in polyphenols, in particular epicatechin gallate, also found in green tea, and ellagic acid, which is found in many fruits

All of the wines were rich in polyphenols, in particular epicatechin gallate, also found in green tea,and ellagic acid, which is found in many fruits. When the team ran PPAR-gamma binding assays, they found that not only did these compounds bind to the receptor, but that the wines contained enough of them to rival the activity of the potent drug rosiglitazone, which is used to treat type 2 diabetes. One of the wines, a 2003 Blaufränkisch, contained particularly high polyphenol levels – just 100 mL contained levels equivalent to about four times the daily dose of rosiglitazone. 

Jungbauer says that tannin-rich red wines contain more of the polyphenols, but that it is too early to come to any general conclusions about grape varieties. However, he suspects that environmental factors and wine technology have as much influence as the type of grape. He points out: ‘grape tannin and oak tannin supplements are often used in wine technology as antioxidants, and are added to the mash or fermented must. These extracts are rich in polyphenols and may also be a potent source of PPAR-gamma ligands.’ 

Chi-Tang Ho, a food scientist at Rutgers School of Environmental and Biological Sciences, New Jersey, US, thinks that this is an ‘extremely exciting’ study, and that it provides ‘good experimental evidence for the potential anti-diabetic effect of drinking red wine in moderation.’ ‘Grape skin extracts have great potential, and although the influence of ethanol is not yet fully understood, I am confident that it will be possible to replace some synthetic compounds by plant extracts,’ concludes Jungbauer. 

David Barden 

Read more about the article here:

Red wine: A source of potent ligands for peroxisome proliferator-activated receptor
Alfred Zoechling, Falk Liebner and Alois Jungbauer, Food Funct., 2011, DOI: 10.1039/c0fo00086h

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Liquorice compounds show dual anti-cancer and anti-inflammatory properties

Graphical abstract: Inhibitory effects of 1,3-bis-(2-substituted-phenyl)-propane-1,3-dione, β-diketone structural analogues of curcumin, on chemical-induced tumor promotion and inflammation in mouse skin‘Dibenzoylmethanes (DBMs), isolated from liquorice, have excellent anti-inflammatory and anti-cancer effects,’ claim scientists in Taiwan and the US.

DBMs are β-diketone structural analogues of curcumin and have an aspirin-like skeleton. Curcumin and aspirin are known to possess anti-inflammatory and chemopreventive effects through suppression of COX-2 gene expression.  Due to the structural similarities between DBM and curcumin and aspirin, Chuan-Chuan Lin and co-workers tested the anti-inflammatory and anti-cancer effects of DBMs. They found DBMs to have the potential to substitute for aspirin in therapeutic anti-inflammation treatment. In addition, they also noted the DBMs activities as an anticancer agent.

The team from the China University of Science and Technology and the State University of New Jersey in the US believes that DMBs acts by inhibiting the COX-2 enzyme. It is known that expression of COX-2 is associated with chronic inflammation and epithelial carcinogenesis. The team used the tumour promoting agent 2-O-Tetradecanoylphorbol-13-acetate (TPA), which induces COX-2 expression causing tumours and ear edema in the skin of mice. Lin et al. found that DBMs inhibited TPA-induced skin tumours significantly and that some of the DMB compounds possessed superior anti-inflammatory properties than aspirin. 

Read more about this paper here:
Inhibitory effects of 1,3-bis-(2-substituted-phenyl)-propane-1,3-dione, β-diketone structural analogues of curcumin, on chemical-induced tumor promotion and inflammation in mouse skin
Chuan-Chuan Lin, Yue Liu, Chi-Tang Ho and Mou-Tuan Huang
Food Funct., 2011, Advance Article
DOI: 10.1039/C0FO00098A, Paper

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