Study will help firms support health claims

Scientists will have a better understanding of how the body can take advantage of functional nutrients found in different food structures, following the results of a new collaborative research project.

This should help firms make successful health claims submissions to the European Food Safety Authority (EFSA). To date EFSA's Panel on Dietetic Products, Nutrition and Allergies (NDA) has rejected huge swathes of health claims dossier submissions, many because of the failure to adequately characterise foods and the claimed beneficial effects they describe before substantiating the claims.

"Before we can actually put a health claim on a packet we have first got to be able to prove that there is a functionality and those ingredients are actually giving us that health benefit they claim to do," said Professor Martin Wickham, head of nutrition at Leatherhead Food Research (LFR).

Complex process

"But that is not an easy process because, although you put the ingredient in the food, it does not necessarily mean that ingredient gets to the 'site of activation' in our body it's a very complex process that food has got to go through."

Wickham added: "Once we get to the site of activation we can probably do a human study; we can collect some samples and say that this functional active is probably bioavailable."

The main aim of the project, which started last year and is expected to continue through 2013, is to understand how fundamental food structures influence the 'bioaccessibility' a term used by food scientists, which is related to the 'bioavailability' or description of how the body absorbs different nutrients of model nutrients. It takes account of the complex process of processed food digestion as it passes through the body to the small intestine. "Release from the food structure is a hurdle in itself," remarked Wickham.

Site of activation

"It is very difficult for an active [component] once it is put in the mouth to get to the site of activation. How do you measure that? In humans it is very difficult."

Describing the research, which is a collaboration between LFR, the University of Messina, University of Palermo and the Institute of Food Research in Norwich, at a recent LFR nutrition conference, Wickham reported that a secondary aim of the work was to correlate in vitro bioaccessibility as a predictive model of in vivo bioavailability.

"They [in vitro models of the stomach] are really powerful tools," he added. "But in vitro models alone are limited; you need to run them in parallel with in vivo studies."

Using components in prickly pear pulp as model compounds, four food matrices containing a mixture of the phytochemicals betanin and indicaxanthin are being investigated to determine the effect of food matrix on bioaccessibility in vitro. The outcome of this research will be used to design an in vivo bioavailability study next year.