Whey proteins are widely used in the sports supplement industry in the different forms available, i.e. concentrated, isolated or hydrolyzed. The food industry also generally makes extensive use of them as gelling agents (yogurt, ice cream), adjuvants in baked products (finished product elasticity, surface browning, egg replacement) up to the “cheese analogs” industry where their use is varied and massive.
The hydrolysis of whey proteins in particular conditions and with “clean” and innovative ultrafiltration processes can generate particularly transparent proteins in aqueous solution even at rather high concentrations (up to and above 20%).
Protein hydrolysis is carried out in a more or less strong acidic environment, therefore using acids which impart a more or less astringent taste to the powder once solubilized. A common characteristic of these transparent whey proteins is therefore the pH of the solution obtained after dilution which is never lower than 3.2 and a practically neutral and astringent taste which is however not typical of dairy products.
The application in the food industry cannot therefore ignore these characteristics, together with others specific to this class of very particular raw materials.
If normal whey proteins or caseins are widely used for shakes or high-protein RTD drinks, the application of acid hydrolysates must follow other applications in which the astringent acid effect (and low pH) are not a limitation but an advantage for the finished product.
A recent application has made it possible to obtain popsicles containing 10% hydrolyzed whey proteins, without affecting the taste or pleasantness of the finished product.
Hydrolyzed whey protein is a form of whey protein that has undergone a hydrolysis process, which involves the breaking of the peptide bonds between amino acids. This hydrolysis process fragments proteins into smaller peptides and, in some cases, individual amino acids. Hydrolyzed whey protein is often marketed as a form of protein that can be more rapidly absorbed than non-hydrolyzed protein. Due to their hydrolyzed form, they are also known to be easier to digest for some people than other forms of whey protein.
Popsicles are notoriously a food that is consumed in the summer period, based on sugars and, sometimes, fruit juices, but normally flavored and colored, so as not to be a nutritionally interesting food, but rather almost exclusively thirst-quenching, comforting and for an easy and pleasant consumption. Children and elderly people are often a sales target for these products precisely because of their intrinsic characteristics. Adding nutritional value to these forms of consumption by adding a high percentage of hydrolyzed proteins (10/15%) can be a way of facilitating protein intake in a season of the year where normal sources of supply may not be particularly appreciated and the appetite itself may fail.
The tested proteins were prepared by hydrolysis in an acidic environment using a weak acid (phosphoric acid) due to its limited astringent power at the same pH and final transparency with other acids (for example, citric acid proved to be particularly astringent). Subsequently, ultra filtration and drying were carried out.
The popsicle was prepared with a mixture of sugars (sucrose and 38DE glucose syrup) up to a total of 16% by weight in the finished product and enriched with protein until reaching 10% protein on the weight of the popsicle. Different flavorings were tested (mint, strawberry, orange, berries) thanks to the use of concentrated juices, aromas and colors. The low pH of the solution contributed to the brilliance of the natural colors used.
The finished product was neutral and extremely pleasant.
It was noted that adjusting the pH with bases above 3.5 tended to decrease clarity and distort flavor. A decrease in transparency was also observed in the case of heating the solutions above 80°C. The temperature also tends to activate the residual gelling power of the protein which however, at temperatures lower than 60°C, remains particularly fluid. Given the pH of the finished product, pasteurization or UHT processes are not industrially necessary as in the casein or whey protein-based versions of high-protein drinks (so-called RTDs).
Applications of hydrolyzed whey proteins from acidic production have also been found in the literature in the preparation of gummy bears and lollipops, products widely consumed by children without positive nutritional properties, bringing new value to products otherwise relegated to spot consumption.
Applications have being studied in the field of fruit-based sorbets to increase the nutritional value in this case too without affecting their taste and refreshing effect. Of course the transparency effect has no application in this specific case while the flavor neutrality is a key aspect together, of course of the high nutritional intake.
