Writing in the International Journal of Food Microbiology, the researchers note that the water-soluble extract possessed anti-fungal activity that could reduce spoilage of the breads during long-term storage under pilot plant conditions.
Furthermore, the amaranth extract was found to enhance the enhanced rheology, sensory, and nutritional properties of the breads, said the researchers from the University of Bari and Barilla G&R SpA (Parma).
The extract added to the protein and total free amino acid values of the bread, enhancing the nutritional profile. Furthermore, the free amino acids could play a role in the flavour of the finished bread, since they act as precursors for flavour development during baking.
The high albumin content of the extract may also enhance the sensory aspects of the bread, added the researchers, with improvements reported in foaming, water and oil absorption capacities, emulsifying activity and stability.
“Amaranth albumins allowed high mixing stability and improved the wheat bread crumb properties,” wrote the researchers, led by Marco Gobbetti.
Gluten-free boom
If future studies support the potential of the extract, it may see gluten-free breads formulated with amaranth ingredients adding to the ever-growing gluten-free market.
According to a recent report from Packaged Facts, the gluten-free market has grown at an average annual rate of 28 per cent since 2004, when it was valued at $580m, to reach $1.56bn last year. Packaged Facts estimates that sales will be worth $2.6bn by 2012.
The market researcher said it expected to see a much wider range of gluten-free products on shelves by 2012, and said that this will be driven by companies reformulating existing products for gluten-free acceptability, as well as by releasing new ones.
Study details
The researchers prepared a water-soluble extract of amaranth seeds, and investigated if they could extend the shelf-life of gluten-free and wheat flour breads.
Using Penicillium roqueforti DPPMAF1 as the indicator fungus, Gobbetti and his co-workers report minimal inhibitory concentration of 5 mg of peptides per ml. Furthermore, results showed that many fungal species isolated from bakeries could be inhibited. The source of the anti-fungal activity was four peptides, said the researchers.
Formulation into gluten-free and wheat flour breads confirmed that the extract “delayed the appearance of fungal mycelium”, said the researchers.
“Further investigation is under progress to exploit the potential of amaranth as natural antifungal in different gluten-containing and gluten-free baked goods,” concluded the researchers.
Source: International Journal of Food Microbiology Published online ahead of print, doi: "Long-term fungal inhibitory activity of water-soluble extract from Amaranthus spp. seeds during storage of gluten-free and wheat flour breads" Authors: CG. Rizzello, R. Coda, M. De Angelis, R. Di Cagno, P. Carnevali, M. Gobbetti