Factors Regulating Astringency of Whey Protein Beverages

Viscosities of thickened model beverages at 20°C. Values are the means of 4 replications. Error bars represent standard deviation. ● = 1.6 mPa·s, no thickener; ○ = 3.3 mPa·s, 10% maltodextrin; ▴ = 5.0 mPa·s, 15% maltodextrin; ▵ = 4.9 mPa·s, 0.27% methyl cellulose; and ■ = 7.7 mPa·s, 20% maltodextrin.

Astringency time intensity of thickened model beverages. Astringency intensity is measured on a 15-point scale. ● = control; ○ = 1.6 mPa·s; ▾ = 3.3 mPa·s; ▵ = 5.0 mPa·s; ■ = 4.9 mPa·s; and □ = 7.7 mPa·s.

Astringency time intensity of model beverages of varying pH. Astringency intensity is measured on a 15-point scale. ● = pH 2.6; ○ = pH 3.0; ▾ = pH 3.4; ▵ = pH 6.8; and □ = pH 3.4 buffer.

Optical density of saliva, model protein beverages, and alum (0.8g/L) mixtures before (black bars) and after centrifugation (gray bars).

Relationship between change in optical density before and after centrifugation and maximum astringency (r² = 0.90). Astringency intensity is measured on a 15-point scale. ● = pH 3.4 buffer; ○ = pH 2.6; ▾ = pH 3.0; ▵ = pH 3.4; and ■ = pH 6.8.