Effect of technological factors on water activity of extruded corn product with an addition of whey proteins.

BACKGROUND The value of water activity in extruded products constitutes a significant indicator of their quality and stability. The state, in which water is found in extruded products, is an indicator of the conducted extrusion process and the used raw material. MATERIAL AND METHODS The aim of the study was to assess water activity in extruded products made from a mixture of com grits with 12.5 and 15.0% moisture contents and different level of addition of whey proteins. RESULTS AND DISCUSSION It was shown that the degree of mixture moisture content did not have an effect on the value of aw in produced puffs. The greatest difference was recorded when introducing 3% proteins in comparison to aw of puffs produced solely from corn grits. Δaw = 0.023. The greater the content of whey proteins, the lower the aw value. A 3-month storage at a temperature of 18 ±0.5°C influenced aw of snacks produced from a mixture with a higher moisture content.