Effect of alkaline salts and whey protein isolate on the quality of rice-maize gluten-free pasta

The objective of this study was to investigate the effect of the addition of alkaline salts (sodium + potassium carbonates) and/or whey protein isolate on the quality of rice-maize gluten-free (GF) pasta. Different levels of incorporation, i.e. 0.5 and 1% alkaline salts, 5% whey protein isolate (WPI) and 1% alkaline salts with 5% WPI, were evaluated. The GF pasta samples were tested for surface microstructure (by Scanning Electron Microscopy), pasting properties, colour, geometrical and cooking quality (weight gain and cooking loss) and textural properties (firmness and compression-extrusion energy). Compared to the control, the alkaline salts addition significantly (p <= 0.05) increased viscosity, cooking loss, redness, yellowness and dimensions, and decreased weight gain, luminosity, firmness, and total compression-extrusion energy of cooked pasta. The WPI addition significantly (p <= 0.05) increased cooking loss (13-18%), luminosity and yellowness of pasta while decreasing viscosity, firmness (22-27%) and total compression-extrusion energy (15%). However, the WPI addition enhanced the nutritional quality by increasing up to 48% the protein content and, in combination with alkaline salts, produced pasta with good cooking performance. The outcomes of this research can be useful in developing healthier GF pasta without extensively penalizing the cooking performance.