Foam milk powder

Kelly, P.M. (2006). Innovation in milk powder technology. Int. J. Dairy Technol. 59,70-75. Kelly, P.M., and Burgess, K.J. (1978). Foaming properties of milk protein concentrate... 

The physicochemical state of fat in milk powder particles, which markedly influences the wettability and dispersibility of the powder on reconstitution, depends on the manufacturing process. The fat occurs either in a finely emulsified or in a partly coalesced, de-emulsified state. In the latter case, the membrane has been ruptured or completely removed, causing the globules to run together to form pools of free fat. The amount of de-emulsified free fat depends on the manufacturing method and storage conditions. Typical values for free fat (as a percentage of total fat) in milk powders are spray-dried powders, 3.3-20% roller-dried powders, 91.6-95.8% freeze-dried powders, 43-75% foam-dried powders, less than 10%. 

The foam spray drying process was developed for dairy industry at the start of the twentieth century. The spray drying of foamed materials was patented in 1917 (Campbell, 1917) to dry foamed milk and egg albumin (Rath and Kudra, 2006), but some 40 years later Sinnamon et al. (1957) found that the vacuum drying of concentrated milk foam would produce a whole-milk powder of good flavor and dispersibility. Morgan et al. (1959) showed that the dispersibility of whole-milk powder could also be maintained in foamed products during drying at atmospheric pressure. 

Tab. 6.2 Physical properties of whole-milk powder produced by foaming with nitrogen. Adapted from Hanrahan etal. (1962).

Creamy flavors in butter have been associated with 4-cis heptenal produced for autoxidation of isolinoleic acid (Begeman and Koster, 1964). Drier flavor in foam spray-dried milk has been associated with 6-rra x-nonenal, which has a flavor threshold in fresh milk of 0.07 pg/kg (Parks et al., 1969). Bassette and Keeney (1960) implicated a homologous series of autoxidation-derived saturated aldehydes, together with products of Maillard browning, in cereal-type off-flavors in powdered skim milk. Staleness in dry whole milk may be associated with saturated and unsaturated aldehydes (Parks and Patton, 1961). 2,4-Decadienal has been reported to be the principal compound responsible for the off-flavor associated with spontaneously oxidized milk (Parks et al., 1963). Oxidized flavors in sunlight-exposed milk are commonly related to C6 to Cn alk-2-enals... 

Processed foods are often colloidal systems such as suspensions, emulsions and foams [1]. Examples of food emulsions, which are the most commonly used products, are milk, cream, butter, ice cream, margarine, mayonnaise and salad dressings. Emulsions are also prepared as an intermediate step in many food processing items, e.g. powdered toppings, coffee whiteners and cake mixes. These systems are dried emulsions that are re-formed into the emulsion state by the consumer. 

One smdy in France showed the foam and eleaning synergy between a C13.6 SME/sulfonated fatty-aeid blend and SLS [35]. In Figure 17 it can be seen that as SME replaces from 15% to 46% of the SLS aetives, the number of washed plates before a foam endpoint is reached is at its highest. The test method used was a large plate test. The soil consisted of water, powdered milk, potato flakes, and hydrogenated eoeonut oil 4 mL soil per plate. The test solution was 5 L of 0.032% actives in 220 ppm water as CaCOj at 45°C. 

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