Impact of the replacement of milk powder by soy flour on chemical properties, texture, particle size distribution and whiteness index of chocolate product

The purpose of this study was to investigate the effects of replacing milk powder with soy flour on the chemical characteristics, texture, particle size distribution and whiteness index of chocolate products. Treatments consisted of two refining times (105 and 135 min) and replacement of milk powder with soy flour at four levels (zero, 33.33, 66.66 and 100%). Results showed that by replacing milk powder with soy flour, moisture content of samples placed below 1.5%, ash and pH values ranged between 1.59 to 1.71% and 7.59 to 7.67, respectively. Particle size and hardness of samples significantly increased with the increase of the replacement level in both refining times, (P <0.05). Generally, extending storage time increased the whiteness index of samples in all replacement levels and both refining times.