Homogenization, of milk

Barium carbonate also reacts with titania to form barium titanate [12047-27-7] BaTiO, a ferroelectric material with a very high dielectric constant (see Ferroelectrics). Barium titanate is best manufactured as a single-phase composition by a soHd-state sintering technique. The asymmetrical perovskite stmcture of the titanate develops a potential difference when compressed in specific crystallographic directions, and vice versa. This material is most widely used for its strong piezoelectric characteristics in transducers for ultrasonic technical appHcations such as the emulsification of Hquids, mixing of powders and paints, and homogenization of milk, or in sonar devices (see Piezoelectrics Ultrasonics). 

It is well established that pasteurization and homogenization of milk reduce its XO activity (Cerbulis and Farrell 1980 Zikakis and Wooters 1980). In a study in which the activity of XO was assayed in 195 commercially processed dairy foods, it was found that commercial processing (homogenization, pasteurization) destroyed about 82% of the XO activity in raw milk (Zikakis and Wooters 1980). 

The fat globules of milk reduce the conductivity by occupying volume and by impeding the mobility of ions. Thus the conductivity of whole milk is less than that of skim milk by about 10%, and that of cream varies with the fat content (Gerber 1927 Muller 1931 Prentice 1962). Homogenization of milk does not measurably influence conductivity (Prentice 1962). The conductivity of whey and ultrafiltrate is slightly greater than that of skim milk (Schulz 1956 Schulz and Sydow 1957). A possible relationship between the electrical conductivity and physical stability of evaporated milk and concentrated infant milk products has been reported (Hansson 1957). Samples of poor physical stability tended to have relatively low conductivity values compared to those of the more stable products. 

Vanillin in MeOH and sulphuric acid was used for the derivatization of MON. Chicken tissue (muscle, liver, skin with adhering fat tissues) samples were homogenized with MeOH-water, NaCl was added to the supernatants, and MON was isolated and concentrated by liquid-liquid partition carbon tetrachloride and by SPE on the silica gel. Standard recoveries ranged from 82% to 96%. The method is specific for MON in the presence of closely related PETs— NAR and SAL. Lasalocid and other antibiotics, such as tylosin, nicarbazin, bacitracin, lin-comycin, and bambermycin, do not react in the system and therefore do not interfere (102). A similar method was also used for the determination of MON in bovine tissues and milk. The homogenization of milk was performed by using MeOH. Recoveries achieved were 79-88% with RSD values of 4.6-9.1% (103). 

Ultrasonic treatment can also disrupt milk fat globules, probably through cavitation and other shear and shock effects (Villamiel, 1999). Wu et al. (2001) reported that high amplitude ultrasound homogenization of milk for yogurt manufacture achieved similar effects as conventional homogenization. 

Effect of Degree of Fat Emulsification as Influenced by Homogenization of Milk, Cream and/or Curd... 

Effect of Homogenization of Milk or Cream, and Degree of Fat Emulsification on Fracture Properties... 

Jana, A.H., Upadhyay, K.G. 1992. Homogenization of milk for cheesemaking - A review. Aust. J. Dairy Technol. 47, 72-79. 

The term homogenization is used, if a uniform liquid phase has to be realized, e.g. a molecularly homogeneous mixture of several miscible liquids or equalization of concentration and temperature differences during a chemical reaction in the liquid phase. (The same term is used in the food industry for a completely different operation, namely for L/L (liquid/liquid) dispersion under extreme shear conditions e.g. the homogenization of milk). 

Figure 22.25 Design of the microstructured reactor used by Kohler et at. [33] for the homogenization of milk with high fat content [33].

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