This work proposes an integrated production of whey protein concentrate (WPC) and lactose and the recovery of water from diafiltration (DF) steps. Whey protein and lactose can be concentrated using ultrafiltration and nanofiltration, respectively, and both can be purified using DF. However, DF uses three-fold the initial volume of whey. We propose a method to reclaim this water using reverse osmosis and adsorption by activated carbon. We produced WPC with 88% protein and purified lactose (90%), and 66% of the water can be reclaimed as drinking water. Additionally, the reclaimed water was used to produce another batch of WPC, with no decrease in product quality. Water recovery from the whey process is necessary to meet the needs of a dairy refinery.

The apple industry uses high flows of potable quality water to transport and clean the apple, which is regularly contaminated. Thus, it is necessary to implement an efficient water treatment system during the industrial process, providing reductions in the intake and release flows. A hybrid system was developed by applying the electrolytic treatment by electrocoagulation using a batch process (Step 1) and a continuous process (Step 2), followed by a microfiltration membrane separation (MSP) process (Step 3). The optimal conditions for removal of organic matter, chemical oxygen demand, total suspended solids (TSS), turbidity, color, and fungi obtained in Step 1 were a hydraulic detention time of 40 min, stirring at 40 rpm, current density of 20 A/m2, pH of 8.00, and temperature of 10 °C. These findings led to a successful implementation in Step 2, which evolved into Step 3, where tests in the combined continuous electrolytic reactor together with MSP showed significant removal rates, notably reaching up to 54% organic matter (OM) removal, 72% chemical oxygen demand (COD) removal, 83% TSS removal, 92% haze and color removal, and 100% mildew removal. The hybrid system proved to be a promising alternative for implementation in the processing industry, minimizing environmental impacts and costs.

The world's production of butter generates 6.5.106 tons per year of buttermilk. This byproduct has important nutrients such as proteins, lactose, and salts. Proteins can be broken to produce peptides, which have biological activity as antioxidant and antimicrobial. This study aimed to obtain peptides of low molar weight from buttermilk by a combined process using enzymatic hydrolysis and ultrafiltration (UF). Different enzymes showed different hydrolysis degrees (HD), as the sequential hydrolysis with Alcalase® and Neutrase® reached a HD of 34 %. UF separated the peptides of low molar weight by applying 100 kPa (1 bar) of pressure and under 40 ºC. The UF membrane (with the molar weight cut off - MWCO in a range of 30 – 80 kDa) rejected 38 % of proteins from hydrolysed buttermilk. The ultrafiltered hydrolysed buttermilk has higher antioxidant activity when compared to the buttermilk. The results have shown that it is possible to obtain peptides with antioxidant activity allied to the valorization of a dairy byproduct from the dairy industry.