Ultrasound assisted crystallization for the recovery of lactose in an anti-solvent acetone

Continuous worldwide increase in high-scale production of dairy products leads to the constant generation of vast amounts of liquid by-product, whey. Disposal of liquid whey is-costly due to its high biological oxygen demand (BOD) and water content. More than 90% of whey BOD is due to lactose. Recovery of lactose from whey solves both the problems of improving economics of whey utilization and pollution reduction as lactose recovery itself can reduce BOD of whey by more then 80%. Commercial effluent treatment techniques focus on degradation rather than recovery of useful by-products like lactose. Also, these techniques are time consuming and hence not effective enough. Sonocrystallization is the use of power ultrasound to control the crystallization process during the nucleation phase. In the present study, the process of lactose crystallization has been studied for the recovery of lactose from reconstituted lactose solutions with the aid of ultrasound, in the presence of 'acetone', as an anti-solvent. The crystallization is found to be completed with excellent yields in the range of 80 - 92% within 4 minutes of sonication. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim