Par-baked poser

09 October, 2009
Page 26 

So (drumroll please)... what's the verdict? "We can say that part baked technology is a good technology," says professor Alain Le Bail, co-ordinator of an EU-funded project that has been pondering the matter. Or at least it could be. It found that par-baked bread demands around twice the energy of conventional breadmaking if the partial baking and the final bake are done in a baking oven. Another problem lies with the freezing of par-baked bread, which demands a lot of energy, especially if it is likely to be stored frozen for longer than a month.

As a result, the industry should push for par-baked bread stored in modified atmospheric packaging (MAP), or gas flushing, and stored at room temperature, argues Le Bail. He gave BB a sneak preview of the EU-Freshbake project findings, due to be unveiled at the IBA exhibition in Germany this week. They showed that with frozen par-baked bread, the freezing demands around as much energy as the first and second bake (so one-third par-baking, one-third freezing and one-third final baking). After just one month of frozen storage, the energy use will be roughly double the energy spent on par-baking, freezing and final baking, without even factoring in the energy used in frozen distribution.

Consequently, the report recommends:
l the industry should try to favour non-frozen par-baked versus frozen par-baked, mainly because of the energy needed for frozen storage;
l par-baked offers several advantages, including less waste because you just prepare what you need (at home, in the bakery and in baking stations);
l when the final baking of par-baked is done in a simple home toaster, the energy for par-baked is similar to the one for conven-tional baking.

Perhaps more significantly, the project developed ground-breaking oven baking concepts that could give rise to 40-50% energy cuts and a 70% reduction in time spent heating the oven. A patent application has been made by the French national scientific council for research (CNRS), which accounts for an energy reduction of around 35% in a complete baking cycle: preheating plus partial baking plus final baking.

The invention involves a baking oven for dough made using cereal flour in particular a fermented dough. The oven has a sole in refractory material and thermally insulated surrounding walls. The quantum leap from regular ovens comes from heating via IR radiation lamps located in the top of the cavity of the oven and directed towards the sole.

"No other heating means are required. Baking can be done as usual in a two-step process preheating followed by baking," says Le Bail. Comparison of energy consumption and bread quality have been trialled on two similar commercial ovens; one oven was modifed with the invention and the second was used as a control. Results showed that pre-heating time to 200C without streaming was dramatically cut from 40 to nine minutes. Energy consumption in the preheat dropped from 4,100Wh to 2,450Wh.

"The technology installed in an oven specifically designed for it may, we think, result in a reduction of energy by 50%," he says. "One important point is that the percentages that we give do not accommodate the energy for the steaming system, which is very often excessive versus the real need. The ovens in the market have too powerful steam systems." Moisture content, hardness, pore size and colour are claimed to be unaffected by this baking process.

Another unexpected bonus of the project is, that using existing ovens, par-baked bread was found to have a lower Glycaemic Index (Gi) rating than conventionally baked bread with the lower Gi rating meaning people eating it feel fuller for longer. Conventional bread scored an 83-point rating and par-baked frozen scored 60. This equates to a 28% reduction with the same recipe. "This was one of the major nice surprises from the project," says Le Bail. "We think that this can become a marketing advantage for par-baked technology."

A good practice guide for bake-off will be made available in November, which will cover energy use, process control, nutrition and product quality.

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