With infant formula, what’s critical is the protein is high-quality and complete.

Alpha-lactalbumin for infants and beyond

Today’s adults may be striving to increase protein intake, but when it comes to infants, their under-developed digestive systems may handle only about 10% protein at each feeding. This is what you get with mother’s milk.

With infant formula, what’s critical is the protein is high-quality and complete, meaning the protein component of infant formula should contain all essential amino acids in appropriate proportions in order for protein synthesis in the body to proceed at optimal rates. Whey proteins are just that and therefore are commonly used in infant formula.

However, beta-lactalbumin is the dominant protein in whey, whereas alpha-lactalbumin is the major protein in human milk. With alpha-lactalbumin being the second-highest protein in whey, ingredient suppliers have been able to isolate and purify it for use in infant formula and other nutritional drinks.

“Alpha-lactalbumin can be used to improve the overall amino acid composition of an infant formula, allowing for a lower total protein level,” said Polly Olson, vice-president of new business development, sales and marketing, Davisco, Eden Prairie, Minn., a business unit of Agropur Inc. “The most desirable aspect of alpha-lactalbumin is its high concentration of the limiting amino acid tryptophan. A low tryptophan level in infant formula is a typical result of total protein reduction, thus the need for the addition of alpha-lactalbumin. Recent research also has shown that alpha-lactalbumin increases calcium and zinc absorption, which is desirable. An appropriate use level of alpha-lactalbumin is 20% to 25% of the protein content of the formula.”

There are a number of alpha-lactalbumin-enriched dairy ingredients in the marketplace to assist manufacturers with formulating a product that more closely resembles human milk, providing infants the best nutrition possible. Davisco recently commercialized production of the first alpha-lactalbumin isolate ingredient, which is more than 92% pure alpha-lactalbumin.

“It took us two years, and today, using proprietary ion-exchange technology, we have a highly purified alpha-lactalbumin ingredient available in large quantities,” said Craig Sherwin, Davisco’s research director.

In addition to “humanizing” infant formula, other health and wellness benefits of alpha-lactalbumin consumption are under investigation. For example, as a rich source of tryptophan, alpha-lactalbumin produces the biggest increases in brain tryptophan, which impacts serotonin synthesis. Serotonin has been shown to have a positive impact on mood, anxiety and stress control.

“It is possible that alpha-lactalbumin-formulated foods could be designed to improve sleep quality or reduce stress-related overeating, among other well-being benefits,” said Rob Markus, professor of neuropsychology at Maastricht University in The Netherlands.