Dairy product and process

Abstract

A method for preparing a modified whey protein concentrate (WPC) or whey protein isolate (WPI) is described. It involves (a) providing an aqueous WPC or WPI solution having a protein concentration of 15-50% (w / v), at a pH of 4.7-8.5; (b) heat treating the solution to more than 50° C., for a time that allows protein denaturation to occur; the heat treating comprising heating the solution while under conditions of turbulent flow. At the end of the heat treatment, the heat treated material may be promptly transferred to a drier or to be mixed with other ingredients. The heat-treated WPC or WPI is not subjected to a mechanical shear process prior to the transfer other than where liquid is converted into droplets to facilitate drying. The modified WPC is useful in the manufacture of food and drinks where a high protein content is desired without undesirable changes in texture.

Description

TECHNICAL FIELD [0001]This invention relates to a process of making a whey protein concentrate (WPC) comprising denatured whey proteins.BACKGROUND ART [0002]Aggregates of heat denatured whey protein have been produced for many years. Lactalbumin is long known as a commercial product prepared by heating whey until the protein coagulates and is rendered insoluble. The insoluble material is filtered off, washed and dried. Lactalbumin has found many uses ranging from stock food to enhancing the protein content of bread and bakery products. The protein depleted whey stream resulting from the recovery of the lactalbumin may also be used as a stock food, but is otherwise expensive to dispose of.[0003]Many attempts have been made to make the production of denatured whey protein both more economic and more commercially useful. Much of the effort has been directed towards increasing the protein content of the whey by selectively removing the lactose content. The achievement of high protein co...

AI Technical Summary

Benefits of technology

[0070]The WPC starting material in (a) may be prepared by ultrafiltration of a raw whey at a pH of about 4.0-6.4, preferably pH 4.0-6.2, more preferably pH 4.0-6.2 and most preferably pH 4.6-6.0. Using ultrafiltration, water, lactose and minerals are removed, resulting in a retentate stream. Diafiltration may be applied during ultrafiltration to further reduce the level of dialyzable components. The ultrafiltration is typically carried out at 10-50° C. Ion exchange may be used to manipulate the ionic content of the proteinaceous stream. The level of calcium ions may be manipulated in some embodiments by ion exchange and replaced with monovalent cations. In other embodiments, the level of calcium may be increased by the addition of a soluble food approved calcium salt e.g. calcium chloride. The protein concentration of the WPC is preferably further increased by evaporation. Alternatively, the starting material may be a reconstituted whey protein prepared from a dried WPC or WPI.

[0073]The use of a high pressure tubular heater is preferred as a flow conduit, mainly because of its simplicity. The heating time varies according to the temperature used. At higher temperatures, for example 100° C., only a few seconds may be required. At 70° C., heating for a longer period may be required. It is also important to note that the degree of heating is a way of modifying the functional properties of the final powder. In different food applications, a wide range of modified WPCs with varied levels of protein denaturation may be required, and this invention provides a simple means of making these, just by modifying the protein concentration, pH, ionic environment, heating time and / or heating temperature.

[0078]A feature of the current invention is that the whey protein concentrate, at high total solids (e.g. >20%), is heated under turbulent flow. Because of the turbulent flow, the heat transfer coefficient is very high, resulting in fast heating. Effectively, the process of this invention offers a very efficient way of manufacture of micro-particulated whey protein products.

Problems solved by technology

The protein depleted whey stream resulting from the recovery of the lactalbumin may also be used as a stock food, but is otherwise expensive to dispose of.

In other applications, these gelling properties are undesirable.

Hoist et al declare: It is surprising that the new, partially denatured whey protein product with a denaturation level of preferably about 80% and a mean particle diameter in the range of preferably 40 to 50 μm has such good organoleptic properties and is free of any sandy or gritty aftertaste, whereas denatured whey proteins with similar particle sizes, as known, because of their bad organoleptic properties, particularly their sandy sensation in the mouth, are unsuitable of use as an additive to mayonnaise which is produced cold.

Images