The combined use of progressive and block freeze concentration in lactose?free milk: Effect of process parameters and influence on the content of carbohydrates and proteins

This work focuses on the study of concentration lactose-free milk using a combination progressive freezing (PFC) with block (BFC). First, we investigated PFC skim applying response surface methodology. To analyze influence three factors (stirring rate, coolant temperature, and assay time) variables (concentrate yield, efficiency process, index, average ice growth rate), central composite design was used previously. It found that all had significate responses. Then, once optimized condition for this step chosen (time 58 min, temperature ?5°C, mechanical stirring 1,035 rpm), obtained from it subjected to new freeze cycle BFC assisted by vacuum. In concentrated fraction cycle, protein carbohydrate contents were equals 6.7 g 100 g?1 10.24 g?1, respectively. The results suggest in carbohydrates accumulate more phase, while is has greatest tendency pass into liquid. approach, believe possible combine two techniques (PFC + vacuum-assisted BFC) obtain concentrates, they can be development innovative dairy products. Practical Applications use processes facilitate customization products rich proteins meet specific requirements nutritional functional properties, instance bakery products, formulated food, ice-cream, beverages, energy drinks, others. Moreover, since most changes occur an aqueous environment, removal some part water its preservation. Within processes, emerges swiftly thanks inherent features, involving low-temperature processing selective nature step. Because low temperatures concentration, technology gaining popularity as alternative technique standard currently processing. offers enhanced sensorial qualities because decreases quality deviation minimizing heat abuse sensitive components, such proteins, water-soluble vitamins, aromatics.