Effects of the addition of various minerals, proteins and salts of organic acids on the principal steps of α-lactose monohydrate crystallisation

Abstract

To study the effects of whey constituents on lactose crystallisation, a model based on population balance and taking into account mutarotation was implemented. Outputs were the nucleation constants (B 0 , k n0) and the growth rate constants (kg 0 , g 0). Batch crystallisation of a lactose solution (70 g 100 g À1 water) was studied with and without addition of various organic acids, salts, galactose and proteins. Kinetics and crystal size distributions were monitored using refractometry and laser light scattering. Factorial analysis of the results highlighted that the presence of organic acids (lactate, citrate) leads to faster crystallisation and confirmed the fact that whey proteins are slowing down the crystal growth step. The results of this study make a contribution towards a better understanding of lactose crystallisation.

Effect of sodium citrate on lactose crystallization in concentrated whey

“…Crystals larger than 50 lm were found at the end of crystallization for the control treatment. The work carried out in model solutions by Gernigon et al (2013) found that larger lactose crystals had been formed when sodium citrate was present. The present work has demonstrated how the addition of sodium citrate salt influenced lactose crystallization in whey concentrate which, unlike model solutions, has other constituents that influence crystallization, such as whey proteins, casein residues, and other present salts.…”

“…The presence of salts or sucrose has been shown to influence lactose crystallization (Gernigon et al 2013). Certain calcium salts such as nitrate increase lactose solubility.…”

“…Patel and Nickerson (1970) demonstrated the complex interaction between salts and lactose during crystallization. A study published by Gernigon et al (2013) showed the positive influence of sodium citrate on the rate of lactose crystallization in model solutions. Patel and Nickerson's (1970) work affirmed the catalytic effect of sodium citrate on lactose mutarotation when the concentration of 1.79 g/L was added in solution containing 60 g/L of lactose.…”

Lactose crystallisation in concentrated whey: the influence of vat type

“…; Gernigon et al . ; Li et al . ), no studies exist that probe whether the type of vat affects lactose crystallisation.…”

“…Although many studies have investigated lactose crystallisation and the drying of dairy products (Guerra-Hern andez et al 2002;Kelly 2006;Syrios et al 2011;Gernigon et al 2013;Li et al 2016), no studies exist that probe whether the type of vat affects lactose crystallisation. The aim of this study was to describe the rate of lactose crystallisation in concentrated whey using two different vats.…”