Optimization of the forewarming process with respect to deposit formation in indirect ultra high temperature plants and the quality of milk

Summary The influence of preheating intensity was examined on deposit formation in an indirect ultra high temperature (UHT) plate heat exchanger and on some quality parameters of the UHT treated milk, such as taste, proteinase inactivation and protein destabilization during storage. Response surface methods were used to define the relationship between the forewarming conditions and the responses. More intense forewarming reduced the fouling rate in the UHT plate section, resulting in longer operation times. While a greater inactivation of the proteinase(s) in the milk was obtained, the taste of the UHT milk was adversely affected, as well as the physical stability during storage owing to higher sedimentation. An optimum temperature/time range for the preheating process could be defined within the temperature/time range of 76–80 °C/40–70 s at which adverse effects were minimal, and positive effects were maximized.

[1]  C. F. Sanders,et al.  Prevention of Milestone Formation in a High-Temperature-Short-Time Heater by Preheating Milk, Skim Milk and Whey , 1944 .

[2]  National Institute for Research in Dairying , 1955, Nature.

[3]  E. O. Herreid,et al.  Amperometric Titration of Sulfhydryl and Disulfide Groups in Milk Proteins , 1962 .

[4]  R. Lyster.  The composition of milk deposits in an ultra-high-temperature plant , 1965, Journal of Dairy Research.

[5]  H. Burton.  Seasonal variation in deposit formation from whole milk on a heated surface , 1967, Journal of Dairy Research.

[6]  Deposition of Milk Solids on Heated Surfaces , 1968 .

[7]  H. Burton,et al.  Section G. Deposits from whole milk in heat treatment plant—a review and discussion , 1968, Journal of Dairy Research.

[8]  Some features of the heat stability of concentrated milk. II. The effect of hydrogen peroxide. , 1970 .

[9]  M. Kaláb,et al.  Heat-Induced Milk Gels. V. Some Chemical Factors Influencing the Firmness , 1972 .

[10]  Changes throughout lactation in the amount of deposit formation from milk of individual cows , 1972, Journal of Dairy Research.

[11]  C. Schwabe.  A fluorescent assay for proteolytic enzymes. , 1973, Analytical biochemistry.

[12]  R. Townend,et al.  Heat Denaturation of Whey and Model Protein Systems , 1974 .

[13]  H. Swaisgood,et al.  Sulfhydryl and Disulfide Groups in Skim Milk as Affected by Direct Ultra-High-Temperature Heating and Subsequent Storage , 1976 .

[14]  R. Lyster,et al.  Whey protein denaturation in heated milk and cheese whey , 1979, Journal of Dairy Research.

[15]  H. Burton,et al.  Effect of free fatty acids on the amount of deposit formed from milk on heated surfaces , 1979, Journal of Dairy Research.

[16]  P. Skudder,et al.  Effects of adding potassium iodate to milk before UHT treatment: I. Reduction in the amount of deposit on the heated surfaces , 1981, Journal of Dairy Research.

[17]  Georges Corrieu,et al.  Fouling of a plate heat exchanger used in ultra-high-temperature sterilization of milk , 1984, Journal of Dairy Research.

[18]  P. Skudder,et al.  Effect of pH on the formation of deposit from milk on heated surfaces during ultra high temperature processing , 1986, Journal of Dairy Research.

[19]  Deposit formation in UHT plants. I. Effect of forewarming in indirectly heated plants , 1986 .