Spray-dried whey

The state of lactose has a major effect on the properties of spray-dried whey powder manufactured by conventional methods, i.e. preheating, condensing to about 50% total solids and drying to less than 4% water. The powder is dusty and very hygroscopic, and when exposed to ambient air it... 

Leviton, A. and Leighton, A. 1938. Separation of lactose and soluble proteins of whey by alcohol extraction-extraction from spray dried whey powder derived from sweet whey. Ind. Eng. Chem. 30, 1305-1311. 

One of the earlier reviews (31 ) concerned the Maillard reaction in dried milk during storage. Spray-dried whey has considerable amounts of lactose and protein rich in lysine. Theoretical treatment of the problem in whey powder was the object of recent studies by Labuza and Saltmarch (106, 107). 

Saltmarch, R. Vagnini-Ferrari, M. Labuza, T. P. Theoretical basis and application of kinetics to browning in spray-dried whey food systems. Prog. Food Nutr. Sci. 

Sato et a2- (34) demonstrated that a variety of common meat additives, inclucnrTg cottonseed flour, nonfat dry milk, spray-dried whey, wheat germ, and textured soy flour, inhibited WOF in the meat system. These products may have exerted their inhibitory effect on WOF through the Maillard reaction, since most of them contain some reducing sugars. Pratt (40) reported soybeans and soy protein concentrate had an inhibitory effect upon development of WOF and was able to demonstrate that the active components are water soluble. Fractionation and analysis of the water-soluble fraction showed the antioxidant activity was due to the presence of isoflavones and hydroxylated cinnamic acids (40). This confirms earlier work showing that the flavonoTcis present in plant extracts inhibit oxidation in sliced roast beef (41 ). 

Saltmarch, M. and Labuza, T.P SEM investigation of the effect of lactose crystallization on the storage properties of spray-dried whey. Scan. Electron Microsc., 3, 659,1980. 

P. Ealdt and B. Bergenstahl, Spray-dried whey protein/lactose/ soybean oil emulsions. Food Hydrocolloids, 10(4), Part 1, 421 29, Part 2, 431 39 (1996). 

Partanen, R., Raula, J., Seppanen, R., Buchert J., Kauppinene, E., Forssell, P., 2008. Effect of relative humidity on oxidation of flaxseed oil in spray dried whey protein emulsions. J. Agric. Food Chem. 56 5717—5722. 

Faldt, P., Bergenstahl, B. (1996). Spray-dried whey protein/lactose/soybean oil emulsions. 1. Surface composition and particle structure. Food Hydrocolloids, 10, 421-429. 

Property Spray process DBM RoUer process DBM Dry whey, extra... 

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. 

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). 

NFDM, which retains casein micelles similar to those in fresh milk, is produced by pasteurization of sklmmllk, vacuum concentration and spray drying under processing conditions that result in either "low heat" or "high heat" product. Low heat NFDM is required for most applications that depend upon a highly soluble protein, as the case for most emulsification applications, since it is manufactured under mild temperature conditions to minimize whey protein denaturation and complexation with casein micelles. 

Partly demineralized whey is produced by subjecting whey to electrodialysis or ion exchange processing treatments to prederen-tlally remove polyvalent ions, vacuum concentrated and spray dryed. 

Industrially, whey proteins are prepared by ultrafiltration or diafiltration of whey (to remove lactose and salts), followed by spray drying these products, referred to as whey protein concentrates, contain 30-80% protein. 

Ultrafiltration/diafiltration of acid or rennet whey to remove varying amounts of lactose, and spray-drying to produce whey protein concentrates (30-80% protein). 

Ion-exchange chromatography proteins are adsorbed on an ion exchanger, washed free of lactose and salts and then eluted by pH adjustment. The eluate is freed of salts by ultrafiltration and spray-dried to yield whey protein isolate, containing about 95% protein. 

Despite some conflicting evidence (Kinsella and Fox, 1986), it appears that denaturation has little influence on the amount of water bound by whey proteins. However, other factors which may accompany denaturation (e.g. Maillard browning, association or aggregation of proteins) may alter protein sorption behaviour. Drying technique affects the water sorption characteristics of WPC. Freeze-dried and spray-dried WPC preparations bind more water at the monolayer level than do roller-, air- or vacuum-dried samples, apparently due to larger surface areas in the former. As discussed above, temperature also influences water sorption by whey protein preparations. The sorption isotherm for /Mactoglobulin is typical of many globular proteins. 

Even though liquid whey has been successfully commercialized in the form of alcoholic and nonalcoholic beverages, these are still a rarity in most countries. Most whey is converted to whey solids as ingredients for human food or animal feeds by traditional processes such as spray drying, roller drying, concentration to semisolid feed blocks, or production of sweetened condensed whey. Jelen (1979) reported other traditionally established processes including lactose crystallization from untreated or modified whey, production of heat-denatured whey protein concentrate, or recovery of milk fat from whey cheese in whey butter. ... 

A general, recent trend has been to apply the principles of ion exchange to the purification of whey or lactose solutions. Anionic and cationic exchange resins are used to remove impurities from the solution, which can then be condensed and crystallized or spray-dried directly. Ahlgren (1977) and Delaney (1976) have reviewed developments... 

Hanrahan, F. P. and Webb, B. H. 1961A. Spray drying cottage cheese whey. J. Dairy Sci. 44, 1171. 

Instantized milk powder normally exhibits low bulk density but higher water dispersibility than conventionally spray-dried powder. However, the extra heat exposure from the agglomeration and redrying treatments causes additional Maillard reaction, whey protein denaturation, and related chemical and physicochemical reactions that tend to lower product quality. 

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