Ultra-high temperature treated milk

Thiazolium salt XTT has been used to evaluate the extent of the Maillard reaction in UHT (ultra-high-temperature)-treated milk, where it proved more rapid and convenient than determination of lactulose, HMF, or furosine.451 To establish the nature of the Maillard reaction products (MRP) involved, the interaction of the aminoreductone from lactose and n-butylamine (Amax = 319.5 nm) with MRP was studied. Excellent correlation (r = 0.967, n = 19) was found between the increased absorbance at 319.5 nm and XTT reducibility, as measured at 492 nm, near Alliax for the formazan, the reduction product of XTT. 

Figure 10-18 Regeneration in Ultra High Temperature Treated Milk as a Function of Storage Temperature. (A) 2°C (B) 20°C (C) 37°C. Source From F. Kiermeier and C. Kayser, Heat Inactivation of Lactoperoxidase (in German), Z Lebensm. Untersuch. Forsch., Vol. 113,1960.

Compatible with protein-rich beverages (e.g., milk-based soy-based) treated with high-temperature short-time (HTST) pasteurization. However, may be issues with flocculation, thickening, or sedimentation due to Ca-protein interactions when subjected to ultra-high temperature (UHT) heat treatment... 

Heat treatment of milk above 60 °C, which promotes whey protein denaturation and its complexation with K-casein at normal milk pH (6.6), also affects renneting properties. An increase in rennet coagulation time and a decrease in gel firmness were observed with increased heat treatment of milk (Menard and Gamier, 2005). Ultra-high temperature (UHT) treated milk failed to coagulate completely but the coagulation properties were restored by threefold concentration of the UHT milk (McMahon ef al., 1993). 

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