Reference Number: 581
Year: 2005
Link: Link to original paper
Health: Key Research Papers
Nutrition: Minerals | Phytic acid
Inclusions: Wheat (whole)
Summary
Whole wheat bread is an important source of minerals but also contains considerable amounts of phytic acid, which is known to impair their absorption. An in-vitro trial was performed to assess the effect of a moderate drop of the dough pH (around 5.5) by way of sourdough fermentation or by exogenous organic acid addition on phytate hydrolysis. It was shown that a slight acidification of the dough (pH 5.5) with either sourdough or lactic acid addition allowed a significant phytate breakdown (70% of the initial flour content compared to 40% without any leavening agent or acidification). This result highlights the predominance of wheat phytase activity over sourdough microflora phytase activity during moderate sourdough fermentation and shows that a slight drop of the pH (pH value around 5.5) is sufficient to reduce significantly the phytate content of a wholemeal flour. Mg “bioaccessibility”of whole wheat dough was improved by direct solubilization of the cation and by phytate hydrolysis.
Significance of this study to the baker:
In this study, it was shown that slight acidification of wholemeal flour dough (pH 5.5) with either sourdough or lactic acid addition allowed a significant phytate breakdown (70% of the initial flour content compared to 40% without any leavening agent or acidification). Phytic acid is an “anti-nutrient” that locks in nutrients within the bread. By breaking down the phytic acid content, these nutrients are made bioavailable, which can make the bread more nutritious.
