US scientists have produced a pizza with enhanced antioxidant content in the crust, aimed to boost antioxidant defences and protect against oxidative stress.
Researchers from the University of Maryland told attendees at the 233rd national meeting of the American Chemical Society that by optimizing baking and fermentation methods the antioxidant content of pizza could get a healthy boost.
But the research has been criticised by a leading dietician for promoting unhealthy eating. Commenting independently on the research, Dr Frankie Phillips of the British Dietetic Association told NutraIngredients.com: "Pizza is never going to be seen as a health food, but it can have a place in the diet occasionally.
"Having a base which is adapted to contain more antioxidants is unlikely to make a huge difference - but the portion size and frequency of eating can impact on whether too much pizza is being eaten. In addition, some toppings contain natural antioxidants; a tomato topping contains lycopene , an antioxidant, and is likely to have a greater bioavailability than fresh tomatoes.
"Pizza toppings can also make a huge difference to the content of fat and salt. But they can be a useful way of adding more fruit and veg to the diet - if toppings such as pineapple, green peppers, onion and sweetcorn are chosen in preference to processed meat toppings and extra cheese - which would add excess fat and salt. Served with a side portion of mixed salad the meal can be well-balanced," she said.
The new research, from Liangli Lucy Yu and Jeffrey Moore at the University of Maryland investigated ways of improving the antioxidant properties of wheat and then incorporating this into a pizza, chosen due to the US' love affair with the food.
"We chose to investigate pizza dough because it's one of the most popular wheat-based food products in the U.S.," said Moore. "Making popular food more healthy using the tools of chemistry may have a larger impact on public health."
Moore and Yu exposed whole grain pizza dough to different baking temperatures, ranging from 205 to 290 degrees Celsius, and to baking times ranging from seven to 14 minutes, and found that longer baking times or higher temperatures corresponded to higher antioxidants levels, compared to less intense baking conditions.
Indeed, antioxidant levels are reported to have increased by 60 per cent during longer baking times and up to 82 per cent during the higher baking temperatures, depending on the type of wheat flour and the antioxidant test used, said Moore.
The fermentation process involved in dough preparation was also found to have an effect on antioxidant activity, with longer fermentation time boosting antioxidant levels, in some cases by as much as 100 per cent.
Moore proposed that this increase might result from chemical reactions induced by yeasts, which had more time to release the antioxidant components that were bound in the dough.
The researchers only studied whole grain wheat since most of the antioxidants in wheat are found in the bran and endosperm components, which have been largely removed in refined flour.
"This research demonstrates the potential of solid-state enzyme and fermentation post-harvest treatments, and optimized processing conditions to improve the antioxidant properties of whole-wheat," stated the researchers.
Moore revealed that the work is on-going with research now focussing on improving the health promoting properties of wheat, developing new varieties with higher antioxidant levels, and investigating how farmers may increase these nutrients during the growing stage.
The study was not funded by the pizza industry, said Moore, but was funded by several US-based grain producing organisations.
Source: 233rd national meeting of the American Chemical Society
March 26 2007, Abstract: AGFD 056
"Enhancing the availability of whole-grain wheat antioxidants through post-harvest treatments and improving processing conditions"Authors: J. Moore, L.L. Yu