The study, published in Journal of Food Science, evaluated the technological and nutritional properties of the African cereals Acha (Digitaria exiliis) and Iburu (Digitaria iburua) in making sourdough bread. The results of the study are said to increase knowledge of the bread making properties of the two flours, and show the suitability of both Acha and Iburu flour to be used for bread making.
The authors, from the department of microbiology at the University of Agriculture, Nigeria, reported that sourdough fermentation of the African grains “increased the nutritional and sensory qualities and the potential application for bakery industry.”
The researchers, led by Raffaella Di Cagno said that interest is starting to focus on ancient and Ethnic grains, which are attracting the interest in both Western and African countries.
They noted that increased use of such grains would decrease the costs related to imported wheat flour, whilst adding that many of the grains have healthier and more natural features when compared to modern wheat.
Non-conventional and ancient grains and cereals have enjoyed a revival of interest in recent years, as they fit with the desire for less processed ingredients and attention to the nutritional value of foods. Acha, also known as white fonio and Iburu, also known as black fonio, are reported to be some of the oldest African cereals.
“It is well positioned for improved production, it is still widely cultivated, and is well known and esteemed for its sensory properties,” said Di Cagno and his colleagues.
However, the bread making process based on Acha and Iburu flours is not well standardised “with consequent negative effects on rheological, nutritional and sensory properties”, they added.
The new study explored the suitability of flour made from Acha and Iburu for sourdough bread making.
Sourdough breads made of Acha or Iburu flours were manufactured using and were compared to wheat
During sourdough fermentations, starter lactic acid bacteria was reported to reach similar cell densities in the non-conventional grain sourdoughs as in the wheat.
The values of in vitro protein digestibility did not differ between Acha sourdough and wheat sourdough breads, however Iburu sourdough bread showed a slightly lower value, said Di Cagno and his co-workers.
The authors found that Acha and Iburu sourdough breads were preferred for hardness and resilience, and were also appreciated for colour, acid taste and flavour, and overall acceptability.
Compared to wheat sourdoughs, Acha and Iburu sourdoughs also contained higher levels of free amino acids
The researchers added that the small size of the grains means have the advantage of being minimally processed, thus limiting the loss of nutrients during milling.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2011.02240.x
“Utilization of African Grains for Sourdough Bread Making”
Authors: R. Coda, R. Di Cagno, C.G. Rizzello, L. Nionelli, M.O. Edema, M. Gobbetti