Thermosonicated whey protein concentrate blends on quality attributes of reduced fat Panela cheese

Aiming at producing a reduced fat cheese (RFC) as an alternative to full-fat Panela cheese, a highly consumed fresh Mexican dairy product, thermosonication (TS) processes (24 kHz, 400 W nominal power, 2, 4 and 6 min; 50, 55 and 60 °C) were evaluated to treat WPC (80% protein) blended with reduced-fat milk (1 and 2% fat), which were later LTLT pasteurized. TS blends were compared in terms of their technological properties (water holding capacity-WPC, gel firmness- GF, color, pH and titratable acidity) with those of a regular full fat (3%) LTLT pasteurized milk used as a control. Afterwards, a regression analysis was carried out with the obtained data in order to select the most appropriate conditions for cheesemaking purposes (similar GF, higher WHC with respect to the control), minimize both fat content and TS treatment duration to minimize energy expenses. According to these restrictions, the selected conditions were 1.5% fat milk-WPC blend, TS treated at 60 °C for 120 s; 1% fat milk-WPC blend, TS treated at 50 °C for 120 s and 1% fat milk-WPC blend, 50 °C for 144 s, which allowed preparing low fat cheeses (LFCs). These TS treatments were applied in a larger scale to elaborate Panela-type LFCs comparing different technological properties (cheese yield, syneresis, water content, texture profile analysis, color and titratable acidity) with those of a full fat variety, at day 1 and during 14 days of refrigerated storage. Results showed similar texture profiles of LFC cheeses and full fat milk cheeses throughout their storage period with significant changes in composition parameters (higher moisture, protein and salt contents, with low fat percentages), syneresis, selected color parameters (hue, b*), with no observed changes in cheese yield, TA and pH during cheese storage. These promising results are encouraging to develop LFCs with no physicochemical or technological defects using novel processing techniques that may help reducing calorie consumption without compromising sensory acceptability