Determination of starch functionality in dehydrated potatoes

The RVA has been used as a measure of starch functionality in dehydrated potatoes, including potato flakes, flours and granules which are used by the snack and baked foods industries world wide. Dehydrated potato flakes are made by pressing cooked mashed potatoes onto a drum drier, which forms a sheet that can be broken up and ground as required. They are used in commercially available products like instant mashed potatoes, croquettes, pasta and fabricated snacks, as a thickener, as a binder and to extend the shelf life of baked goods.

Samples

Three samples of potato flakes were tested on an ‘as is’ basis in the RVA using the STD 1 profile to obtain rapid results. (Graph)

Results

Viscosity measurements are affected by both potato cultivar and processing method. The thermal and mechanical energy input of the drum drying process and the moisture content of the cooked mashed potato are critical factors in transforming the raw starch during processing. Pasting temperature has been reported to be approximately 50°C for potato flakes and approximately 65°C for uncooked potato flour. The presence of a cold pasting peak at approximately 50°C and a hot pasting peak at approximately 65°C indicates that both gelatinized and ungelatinized starch are present in the three samples.