Food or edible material: processes – compositions – and products – Fermentation processes – Of milk or milk product
Patent
1996-11-14
1998-11-10
Tsang, Cecilia J.
Food or edible material: processes, compositions, and products
Fermentation processes
Of milk or milk product
424535, 426583, 530366, 514 2, A23J 120
Patent
active
058340424
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for isolating protein from whey, wherein an oxidant are brought into contact in order to sulfonate, i.e. sulfitolyze, and oxidize the whey protein, whey or concentrate thereof at an acid pH, and from the product mixture and is possibly subjected to an after-treatment.
2. Description of the Related Art
Whey proteins are totally superior to other food proteins as regards their nutritional value and, in particular, their lysin and methionine contents. The recovery of whey proteins and their use in human food would also reduce the costs of cheese production. Although the use of whey protein for human food does have potential, the principal obstacles to its use seem at present to be (1) the high cost of its recovery process and (2) the poor functional properties, i.e. solubility, emulsifiability, gel formation capacity, and foaming capacity, of the concentrate or isolate.
The isolation of whey proteins is complicated by their high solubility, and this cannot be affected by a pH adjustment within the range pH 2-9 while the proteins are in their native form. The isolation of the proteins takes place according to four principal methods: 1. denaturation and precipitation; 2. ultrafiltration; 3. ion exchange; and 4. chemical modification and precipitation.
The most commonly known method for the isolation of whey proteins is denaturation, i.e. heating together with the lowering of the pH to the acid side. The isolation can be carried out economically, for example, as follows: the whey is concentrated to a dry matter content of approx. 20%; the pH is adjusted to the range 6.0-7.0; the proteins are denatured by maintaining the temperature above 90.degree. C. for 10-30 minutes, whereafter the proteins are precipitated by lowering the pH to 4.4-5.0. The protein obtained as a result has lost almost all of its most important functional properties. It is used mainly in various spreads, e.g. processed cheeses, to replace cheese in part or entirely. Hill et al., Can. Int. Food Sci. Technol. J. 15, (1982) 155-160.
Nowadays whey proteins are isolated mainly as a protein concentrate by ultrafiltration and by drying, or as a protein isolate by using ion exchange adsorption techniques and by drying. By both methods it is possible to obtain the isolated proteins in a functional form. The decisive factor in the selection of even these production methods is the functionality of the product and the costs of its production.
There is great variation in the composition, functionality and organoleptic properties of the protein concentrates, and therefore industry shuns their use. The variation is due to different compositions of whey, and to differences in its pretreatment and in the preparation and treatment conditions.
In protein isolates, also, there is variation in the various properties for the above reasons. The ion exchange adsorption method for their preparation levels out the variation to some degree and yields an end product having a composition different from that of protein concentrate.
An analysis of a material according to the publication Morr and Foegeding, Food Technol. 44, (1990) 100-112, which included three whey protein isolates and eight concentrates, showed that their compositions were clearly different. The mean values of the concentrates and isolates were, respectively, as follows: protein concentration 73.8 and 91.0%; non-protein nitrogen 3.10 and 0.32%; water 5.13 and 3.75%; ash 4.27 and 1.82%; lactose 3.92 and 0.57%; and fat 5.00 and 0.57%.
According to the same publication, the isolates were clearly more functional and of a higher quality than the concentrates with respect to the quantity of fat and protein and with respect to the solubility, foaming capacity and stability of the foam of the protein, the non-denaturing and lumpiness of the protein, and taste and odor. The relatively high lactose and mineral contents of the concentrates, and their poor taste and odor, were factors which limited the use of the concentrates in
REFERENCES:
Juan M. Gonzalez, et al., "Recovery of Proteins from Raw Sweet Whey Using a Solid State Sulfitolysis", Journal of Food Science, vol. 55, No. 6, 1990, pp. 1559-1563.
Lukton David
Tsang Cecilia J.
LandOfFree
Method for isolating whey proteins does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for isolating whey proteins, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for isolating whey proteins will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1514399