Table 2.

Effect of processing conditions (pH, ionic strength and heat treatment) on zeta potential and poly dispersity index (PDI) of 5% d-limonene oil nanoemulsion stabilized by whey protein–maltodextrin (1:2 w/w) conjugate

Treatments	Zeta potential (mV)	PDI
Control	− 19.64 ± 0.23	0.205 ± 0.02
Pasteurization (63 °C/30 min)	− 17.29 ± 0.38	0.287 ± 0.01
Forewarming (80 °C/10 min)	− 18.13 ± 0.59	0.273 ± 0.03
Boiling (95 °C/10 min)	− 17.92 ± 0.43	0.297 ± 0.02
Autoclave (121 °C/15 min)	− 17.60 ± 0.36	0.279 ± 0.01
0.1 M NaCl	− 16.19 ± 0.64	0.237 ± 0.05
0.5 M NaCl	− 14.29 ± 0.53	0.265 ± 0.02
1.0 M NaCl	− 13.02 ± 0.78	0.279 ± 0.04
pH 3.0	+5.98 ± 0.49	0.255 ± 0.01
pH 4.0	+0.86 ± 0.39	0.289 ± 0.04
pH 5.0	− 17.21 ± 0.78	0.255 ± 0.03
pH 6.0	− 19.12 ± 0.32	0.225 ± 0.03
pH 7.0	− 20.89 ± 0.26	0.237 ± 0.02

Values are mean ± standard error (n = 3)