Spray dried skim milk

Shiratsuchi, H., Shimada, M., Imayoshi, K., Noda, K., Osajima, Y. 1994a. Volatile flavor compounds in spray-dried skim milk powder. J. Agric. Food Chem. 42, 984-988. 

Other significant recurring themes include studies on the characteristic off-fiavor in spray-dried skim milk powder, which was related to tetradecanal ( sickening, aldehydic ), P-ionone ( hay-like ), and benzothiazole ( sulfuric, quinoline ) contributions at low-ppb levels (123). Fruity ( pineapple-like ) off-fiavors in pasteurized milk indicate the presence of high levels of ethyl butyrate, -hexanoate, -octanoate, and -decanoate esters rancid, soapy tastes arise from decanoic and dodecanoic acids (124). 

H. Shiratsuchi, Y. Yoshimura, M. Shimoda, K. Noda, and Y. Osajima, Objective evaluation of off-flavor in spray-dried skim milk powder, 1. Jap. Soc. Food Sci. Technol. 43 7 (1996). 

Kovacova (1990) describes a method for the batch drying of fruit and vegetable pulp in a fluidized bed in which carrier particles (variously crystalline and caster sugar, dried skim milk, potato and wheat starch, apple powder, semolina or oat flakes), pre-moistened to a solids content of between 55% and 76%, are fed to a preheated fluidized bed and sprayed with the pulp to be dried. A product with a narrow particle size distribution and a uniform pulp content is claimed. Specific foods for which fluidized bed granulation has been used include potato puree (Zelenskaya and Filipenko, 1989) and granulated dried apple (Haida et al, 1994). 

Saito, Z. 1985. Particle structure in spray-dried whole milk and in instant skim milk powder as related to lactose crystallization. Food Microstruct. 4, 333-340. 

Figure 8.6b shows sorption isotherms for dried skim milk, of which about 50% is lactose. The lactose can remain amorphous when the milk is spray-dried. It can also be made with crystalline lactose, and the normal crystalline form is a monohydrate. The water of crystallization is not available as a solvent, which means that aw is smaller than for amorphous sugar at the same water content, provided the latter is fairly small. At higher water content, the curves cross, and amorphous sugar may crystallize, taking up part of the water. 

Ultrafiltration. Membranes are used that are capable of selectively passing large molecules (>500 daltons). Pressures of 0.1—1.4 MPa (<200 psi) are exerted over the solution to overcome the osmotic pressure, while providing an adequate dow through the membrane for use. Ultrafiltration (qv) has been particulady successhil for the separation of whey from cheese. It separates protein from lactose and mineral salts, protein being the concentrate. Ultrafiltration is also used to obtain a protein-rich concentrate of skimmed milk from which cheese is made. The whey protein obtained by ultrafiltration is 50—80% protein which can be spray dried. 

In addition, Montenegro et al., (2007) determined that the photosensitized RF-mediated degradation of vitamins A, D3, and RF itself in skimmed milk was strongly reduced by the addition of small amounts of lycopene-gum arabic-sucrose microcapsules, prepared by spray-drying. Under these conditions, the bulk properties of the skimmed milk were unmodified. The main photoprotection mechanism of the milk vitamins was the efficient quenching of the 3Rf by the protein moiety of GA. Small contributions (<5%) to the total photoprotection percentage was due to both inner filter effect and 1O2 quenching by the microencapsulated lycopene. 

Milk from cows contains 3.2% protein, about 80% of which is casein. Casein is isolated by a precipitation process from milk, involving heating, rinsing to remove whey, and drying to a powder. The yield is about 3 kg/ 100 kg skim milk. Rennet casein is obtained when the casein is precipitated by chymosin enzyme, also known as rennet, and acid casein is produced when precipitation is accomplished by acidification. Acid casein is usually found in the form of sodium caseinate or calcium caseinate, which are water-soluble salts. Caseinates are made by reacting NaOH or CaOH with a slurry of casein curd or powder and then spray drying (Southward, 2010). 

Nonfat dry milk is produced from skim milk by condensing it with conventional equipment followed by spray or drum drying. The drum-dried product is relatively insoluble and is used principally for animal feeds. Over 95% of nonfat dry milk in the United States is used for human foods (American Dry Milk Institute 1982) and is produced by spray drying. Most instant NDM is made by rewetting the conventionally spray-dried product, allowing the particles to agglomerate, and... 

Crystallization of the lactose in concentrated skim milk (40 to 54% total solids) can result in rapid increases in viscosity even during the short interval between concentration and spray drying (Baucke and Sanderson 1970). 

Casein and caseinates are generally made from skim milk by adding hydrochloric or sulfuric acid or by lactic acid fermentation. The isoelec-trically precipitated casein is washed and dried or neutralized with sodium hydroxide, potassium hydroxide, or calcium hydroxide to produce the corresponding caseinate and spray dried. Rennet casein is... 

PIGMENTS DYE STUFF 5, SKIM MILK POWDER PARTICLE SIZE DISTRIBUTION OF SOME SPRAY DRIED POWDERS... 

Twomey, M., Keogh, M.K., O Kennedy, B.T., Mulvihill, D.M. 2000. Effect of milk composition on selected properties of spray-dried high-fat and skim-milk powders. Irish J. Agric Food Res. 39, 79-94. 

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... 

As one of the effects of the Common Agricultural Policy has been to increase the price of all milk products there has been some substitution of skim milk powder by products derived from whey. Impure grades of spray dried lactose derived from whey are offered as a confectionery ingredient. 

Milk powder (from both skim milk and whole milk) is the other form of milk solids used in confectionery. Skim milk was originally roller dried, but this process has now almost passed out of use and modern milk powders are made by spray drying. This does less damage to the proteins than the older roller process such that the bioavailability of the proteins in spray dried powder is higher than in the roller dried form. In confectionery-making this is not a particular advantage since confectionery products do not (or should not) form a major part of the diet. 

Probiotics may be encapsulated in protein-based emulsions. Picot and Lacroix (2003) prepared microcapsules by emulsifying milkfat containing micronized skim milk powder (as a surrogate for freeze-dried bacteria) with heat denatured whey proteins and then spray drying. Incorporation rates of up to 58% milk fat and 29% skim milk... 

The skim milk is spray-dried to recover proteins and carbohydrates. Residue from the screw press and parings are milled to recover oil and coconut flour. 

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