Scientists develop new method for gluten-free flour from sweet potatoes

Led by Ofelia Rouzaud-Sández, the team of researchers sought to establish best practices for processing the flour before it can become a common ingredient in store-bought baked goods.

Several gluten-free options are either already available or in development, including those made from banana peels, almonds and various grains.

Suited for the job

Though previous studies have investigated a variety of parameters, including the way the potatoes are dried and milled, none have yet determined how these different steps could interact with one another to produce flours best suited for certain products.

To create their flours, Sández and her team prepared samples of orange sweet potatoes (Ipomoea batatas) dried at either 122 (55C) or 176 (80C) F then ground them once or twice before being compared to store-bought sweet potato flour and a traditional wheat one.

Regardless of drying temperature, grinding once damaged just enough of the starch to make it ideal for fermented products, such as gluten-free breads, while grinding twice further disrupted the starch’s crystallinity, producing thickening agents ideal for porridges or sauces.

Expanding applications

When baked into a loaf of bread, the high-temperature-dried, single-ground sample featured higher antioxidant capacity than both the store-bought version and the wheat flour. The researchers said the findings could help expand the applications for orange sweet potato flour, both for home cooks and the packaged food industry.

‘Technological Properties of Orange Sweet Potato Flour Intended for Functional Food Products as Affected by Conventional Drying and Milling Methods, has been published in the ACS Food Science & Technology Journal.

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