Resveratrol encapsulation may boost bioavailability
Encapsulating the ingredient in a mixture of chitosan and vanillin was found to reduce degradation of resveratrol associated with light and heat. According to findings published in Food Chemistry, the encapsulated resveratrol was slowly released under conditions designed to mimic the stomach and intestine, which could improve the absorption of the compound.
“Thus, the controlled release and stabilization of resveratrol will provide a more effective and continuous supply of resveratrol within the body,” wrote the researchers, led by Hua Xiong from Nanchang University.
The promise of long life
Resveratrol, a powerful polyphenol and anti-fungal chemical, is often touted as the bioactive compound in grapes and red wine, and has particularly been associated with the so-called 'French Paradox'. The phrase, coined in 1992 by Dr Serge Renaud from Bordeaux University, describes the low incidence of heart disease and obesity among the French, despite their relatively high-fat diet and levels of wine consumption.
Interest in the compound exploded in 2003 when research from David Sinclair and his team from Harvard reported that resveratrol was able to increase the lifespan of yeast cells. The research, published in Nature, was greeted with international media fanfare and ignited flames of hope for an anti-ageing pill.
According to Sinclair’s findings, resveratrol could activate a gene called sirtuin1 (Sirt1 – the yeast equivalent was Sir2), which is also activated during calorie restriction in various species, including monkeys.
Since then studies in nematode worms, fruit flies, fish, and mice have linked resveratrol to longer lives. Other studies with only resveratrol have reported anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.
Bill Sardi, co-founder and president of Resveratrol Partners, says that: “Resveratrol has the biological effects of so many drugs wrapped up in one molecule.”.
Despite such claims, the compound has stability, solubility, and bioavailability issues, which may limit its use in foods and supplements, according to the Chinese researchers.
Dr Xiong and his co-workers investigated the effects of chitosan microspheres cross-linked with vanillin to encapsulate, stabilise and control the release of resveratrol According to their findings, the microspheres produced by their technique were smooth with a size distribution ranging from 53 to 311 micrometres.
Up to 94 per cent of the resveratrol was encapsulated and showed good stbility under light and heat compared with the free resveratrol, they added.
Novel but how efficacious?
Winston Samuels, PhD, president & CEO of Maxx Performance Inc, a company specialising in microencapsulation, described it as “a very novel approach”. Not everyone is convinced by the science, however. Frank DeJianne, DSM’s global business manager for its resVida resveratrol ingredient, told NutraIngredients that the data to support microencapsulated resveratrol is most often limited to in vitro systems.
“Efficacy in humans remains to be demonstrated,” he said.
“From what we can see, microencapsulated resveratrol is not yet sold in the Global ingredient-level marketplace. You can find a few consumer resveratrol products that claim to be microencapsulated, but ambitious marketers may be a bit ahead of the science in this respect.
“In addition to the lack of scientific data, neither regulatory positions nor consumer acceptance (including higher price points) have been validated with microencapsulated resveratrol,” he added.
The company’s ingredient has been verified in human studies to be “well absorbed, and taking it a step further, efficacious at low doses”, said DeJianne.
Source: Food Chemistry
Volume 121, Pages 23–28
“Vanillin cross-linked chitosan microspheres for controlled release of resveratrol”
Authors: H. Peng, H. Xiong, J. Li, M. Xie, Y. Liu, C. Bai, L. Chen
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