Whipping proteins

The foamability of the xylans tested [128] was low in comparison to a commercial whipping protein DIOO. Only the highly viscous beech wood xylan and the rye bran AX-protein complex exhibited remarkable foaming activity, which was similar to that of gum arable. As the MGX polymers contain considerable amounts of uronic acid side chains, this may play a role in their foaming activity together with the presence of low amounts of Ugnin. 

Foaming Capacity and Stability. Pepsin digestion of soy protein has been proposed as a method for making a whipping protein for egg albumen replacement (42, 45) and for extenders for albumen in bakery and confectionery formulations (46). Puski... 

Surface Activity Emulsification, foaming (aeration whipping), protein/lipid film formation, lipid flavor, pigment binding... 

Groninger and Miller (28) succinylated myofibrillar fish protein and then treated the succinylated proteins with bromelain to obtain an acylated mixture of polypeptides. Both the extents of succinylation and enzymic hydrolysis affected the volume of foam of the whipped protein. Optimum foam volume and stability occurred when 54% of the c-amino groups of lysine were acylated and the succinylated protein was mildly hydrolyzed at pH 7, 25°C for 10 min using a bromelain protein ratio of 1 100 (w/w). 

Fig. 19.22. Process diagram for preparing enzyme-modified whipping proteins from soy protein isolate (Source Gunther, 1979).

Gunther, R.C. Chemistry and characteristics of enzyme-modified whipping proteins, ]. Am. Oil Chem. Soc. 1979, 5S, 345-349. 

Whey protein Whilhelmy plate techniqi Whipped cream Whipped toppings Wliipping CTeain Whipworm Whisker reinforcements Whiskers... 

Products prepared from soy protein products and resembling chicken, ham, frankfurters, and bacon are available commercially. Soy protein isolates are used in place of milk proteins or sodium caseinate in products such as coffee creamers, whipped toppings, yogurt, and infant formulas (see Dairy substitutes). Soy protein products also are used in snacks and in baked foods. 

Hydration water, fat, and flavor binding gelation emulsifying foaming and whipping characteristics vary among different soy protein products and complete substitution of animal proteins by these products is not always possible (114). 

Proteins. Proteias are especially significant ia imitation dairy foods with respect to nutritional and physical properties of the product (5). The relative significance of the nutritional quaUty of the proteia depends upon product type and the extent to which the product contributes to the total proteia iatake of a given population. Thus, proteia quaUty is extremely important ia imitation milk, significant ia imitation cheese, and less significant ia coffee whiteners and whipped toppiags. 

The composition of dairy substitutes is highly variable and generally represents the least-cost formulation consistent with consumer acceptance of the product. These imitations invariably have lower fat and protein levels than the dairy products that they are made to resemble. The gross compositions of filled milk, meUorine, synthetic milk, sour cream, coffee whiteners, whipped toppings, and cheese are Hsted in Table 10. A comparison of the composition of certain dairy products and their substitutes is presented in Table 11. 

Isolated soy proteins have also been used in whipped toppings. Soy-protein-based toppings have a lower protein concentration than caseinate-based toppings. Formulations ate adjusted to protein levels, and higher protein levels can result in off-flavors. Typical formulations for a Hquid frozen, prewhipped product are given in Table 18. 

The structure of whipped cream is quite complex. A coating of milk protein surrounds small globules of milk fat containing both solid and liquid fats. These globules stack into chains and nets around air bubbles. The air bubbles are also formed from the milk proteins, which create a thin membrane around the air pockets. The three-dimensional network of joined fat globules and protein films stabilizes the foam, keeping the whipped cream stiff. 

Actually, vegetable proteins can be whipped by the diffusion method to produce frappes which weigh less than /s pound per gallon, whereas this same material, if whipped on a conventional, vertical, or horizontal beater, could not produce this specific gravity, because of the heat involved due to shearing and the denaturation of the protein material due to constant beating. 

When there is a high percentage of proteins, such as in gelatin—which will form an elastic film in conjunction with corn sirup and other sugar products—stability is not too much of a problem. In freshly whipped egg or vegetable protein foams, frappes, or mazettas, in which the foam product is incorporated as part of a complete food batch, the foam is assimilated before its stability becomes a factor and further processing tends to stabilize the foam. 

On the other hand, in preparing whipped products which are to stand for a long period of time, it is often necessary to add various gums, such as Irish moss, algin, and locust bean gum, to have a product that will react in some way with the protein being whipped, to make a firm film and stable foam. 

Secondly, a stable icing foam requires a low surface tension. Consider the case of egg whites in a beater. With slight whipping, entrapped air bubbles are large and the whites appear foamy, yet transparent and runny. With longer whipping the whites become less transparent, white, and more solid. Thus, because of the low surface tension inherent in the egg protein in solution, more and more air may be incorporated and held in place by the colloidal protein which forms a film around each air cell. 

Whipped toppings, either gas dispenser or mechanical, present many problems in foam stabilization. Usually less fat is used in gas-dispensed types. All-vegetable protein whips are now on the market. The percentage of fat, emulsifiers, and gum stabilizers varies with the type of whipping and personal preference. 

Milk Proteins. As some milk proteins will gel on heating and others can be modified to make whipping agents it has long been thought that milk proteins could be used as whole or partial substitute for egg proteins. Purified whey proteins were regarded as a suitable raw material as whey is a low value by-product from cheese making. Early... 

Soya Proteins. Early attempts to make albumen substitutes from soya protein also ran into problems. A bean flavour tended to appear in the finished product. A solution to these problems has been found. Whipping agents based on enzyme modified soy proteins are now available. The advantage of enzymatic modification is that by appropriate choice of enzymes the protein can be modified in a very controlled way. Chemical treatment would be far less specific. In making these materials the manufacturer has control of the substrate and the enzyme, allowing the final product to be almost made to order. The substrates used are oil-free soy flakes or flour or soy protein concentrate or isolate. The enzymes to use are chosen from a combination of pepsin, papain, ficin, trypsin or bacterial proteases. The substrate will be treated with one or more enzymes under carefully controlled conditions. The finished product is then spray dried. 

---