Визначення якісного складу ультрафільтраційного концентрату знежиреного молока

Abstract

Розглянуто питання мембранної обробки знежиреного молока. Проаналізовано результати теоретичних досліджень щодо доцільності застосування ультрафільтрації в технології переробки знежиреного молока. Подано результати експериментальних досліджень показників якості знежиреного молока та продуктів його ультрафільтраційного концентрування залежно від технологічних параметрів процесу.

The paper presents new methods of processing the findings on the ultrafiltration (UF) concentration of skimmed raw milk by means of a new method to prevent building up a polarization layer on the membrane. Food liquids were treated by ultrafiltration with flat membrane module elements (the membranes proper). The process was carried out in dead end mode with the application of the perforated vibrating disc and bubbling device, as the method of intensification. The paper reveals the research findings on the influence of bubbling method on a polarization layer during the membrane processing of skimmed milk and on the performance of ultrafiltration membranes. The devised mathematical models are based on the regression equations of the factorial experiment on the selection of technological parameters of the UF-concentration of skimmed milk with the use of the feedstock bubbling over the membrane surface. The authors determined rational working parameters of the process, which are as follows: the working pressure is 0,4–0,5 MPa, the skimmed milk temperature – 40…50 °C, the skimmed milk bubbling frequency – 0,10–0,15 min-1 , and the bubbling pressure – 0,56–0,58 MPa. Analytical and experimental studies show technological limits of the regulation modes for receiving concentrate in ultrafiltration concentration process of food liquids. It is experimentally proved that the bubbling method that has the advantage of preventing the formation of a polarization layer improves the efficiency of the UF-separation of skimmed milk. Research of the PAN-types of UF-membranes in the UF-concentration of skimmed milk shows that the proposed method of controlling the polarization layer on the membrane can improve the latter’s performance due to a thinner layer of the accumulated macromolecular substances thereon and an enhanced working surface of the membrane.