Glycosylation and expanded utility of a modified whey protein ingredient via carbohydrate conjugation at low pH

Total height of each emulsion (HE) and the height of the droplet depleted layer (HD).

Ionization mass spectrometry chromatography data, in duplicate, illustrating β-LG peaks from nonheated modified whey protein concentrate (mWPC) samples and lactosylated β-LG from heated mWPC samples.

A) SDS-PAGE banding pattern of whey protein and whey protein-carbohydrate conjugates. Lane 1 = marker protein; lane 2 = commercial whey protein concentrate (cWPC); lane 3 = modified whey protein concentrate (mWPC); lane = heated mWPC; lane 5 = heated mWPC-dextran (DX) 35; lane 6 = heated mWPC-DX100. Samples in lanes 4, 5, and 6 were heat treated (100°C, 2h) under dry conditions. All samples were initially prepared at pH 3.5, before electrophoresis, except for cWPC, which was prepared at pH 6.6. B) SDS-PAGE glycoprotein staining pattern of whey protein and whey protein-dextran test samples as loaded in the same order.

A) Apparent viscosity of reconstituted nonheated modified whey protein concentrate (mWPC; 7% protein, wt/vol) with or without dextran (DX) and prepared at a 2:1 ratio, over the shear rate range from 0.1 to 500s⁻¹ at 25°C. Error bars represent 1 standard deviation from the mean; B) apparent viscosity of reconstituted heated (100°C, 2h) mWPC (7% protein, wt/vol) with or without DX and prepared at a 2:1 ratio, over the shear rate range of 0.1 to 500s⁻¹ at 25°C. Error bars represent 1 standard deviation from the mean.

A) Small amplitude oscillatory shear data for reconstituted nonheated modified whey protein concentrate (mWPC; 7% protein, wt/vol) with or without dextran (DX) and prepared at a 2:1 ratio. Closed symbols indicate G′ values and open symbols indicate G″ values. Error bars represent 1 standard deviation from the mean; B) small amplitude oscillatory shear data for reconstituted mWPC (7%, wt/vol) with or without DX and prepared at a 2:1 ratio, after dry heat treatment at 100°C for 2h. Closed symbols indicate G′ values and open symbols indicate G″ values. Error bars represent 1 standard deviation from the mean.

Plot of creaming index values for 5mg/mL protein solutions of commercial whey protein concentrate (cWPC), modified whey protein concentrate (mWPC), and heated mWPC, mWPC-dextran (DX)100, mWPC-DX35 dispersions, prepared at a 2:1 ratio, measured after 1wk at ambient temperature. Error bars represent 1 standard deviation from the mean. All samples were prepared at pH 3.5 except for cWPC, which was prepared at pH 6.6. ^a–eDifferent letters indicate significant differences (P<0.05).

Scanning electron micrographs of modified whey protein concentrate (mWPC) and mWPC-dextran (DX) samples (5.6% protein, wt/vol). A) mWPC, 2,500× magnification, scale bar = 10μm; B) mWPC-DX100, 2:1 ratio, 2,500×, scale bar = 10μm; C) mWPC, 15,000×, scale bar = 1μm; and (D) mWPC-DX100, 2:1 ratio, 15,000×, scale bar = 1μm.

Changes in the water-holding capacity of nonheated and heated modified whey protein concentrate (mWPC; 5.6% protein) prepared in the presence and absence of dextran (DX, 2:1 ratio) at pH 3.5. ^a–dDifferent letters indicate significant differences (P<0.05).