Berry-enriched protein matrices pass sensory and stability tests as functional food ingredients

Additional sensory analysis by experts indicated that cranberry-enriched soy protein isolate could be used in functional food products like “berry-flavored smoothies, protein bars or similar formulations,” said scientists from North Carolina State University and Rutgers.

“The nutritional analysis and sensory characteristics of the products suggest the potential for their commercial use in highly functional food products,” wrote the researchers, led by Dr. Mary Ann Lila, director of N.C. State’s Plants for Human Health Institute.

Nutrasorb

Nutrasorb LLC has licensed the technology described in the journal article from Rutgers University. As reported previously, the bioactive sorption technology works by impregnating soybean flour with antioxidant-rich berry or fruit extracts.

Rutgers University researchers published their findings in Food Chemistry (doi: 10.1016/j.foodchem.2011.09.103), which indicated that 1.4 grams of blueberry-impregnated defatted soybean flour provides the same polyphenol content as 73 grams of fresh blueberries. Similarly, 1 gram of the cranberry-impregnated defatted soybean flour has the equivalent polyphenol content as three 8-ounce glasses of cranberry juice.

The new study, published in the Journal of Agricultural and Food Chemistry, advances these developments and found that approximately 1 gram of the polyphenol-enriched matrix could deliver the same amount of proanthocyanidins (PACs) as in one cup of commercial cranberry juice cocktail.

This dose “has been shown clinically to be the prophylactic dose for reducing recurring urinary tract infections,” said the researchers.

New data

Lila and her co-workers prepared protein-/polyphenol-enriched matrices using concentrate cranberry polyphenols and a range of proteins, including defatted soy flour, soy protein isolate, hemp protein isolate, medium-roast peanut flour and pea protein isolate.

Results showed that the highest concentration of PACs was found in the cranberry-hemp matrix (20.75 mg/g), followed by cranberry-defatted soy flour (17.67 mg/g). The cranberry-hemp and cranberry-peanut protein matrices also had the highest total polyphenolic content (37.61 and 37.12 mg/g, respectively).

“Matrices differ in affinities to cranberry polyphenols in ways that are not completely understood, but which may be a consequence of the distinctive physicochemical properties of their protein components, differences in particle size, surface area, degree of solubility in the juice and the fact that other components of the matrices, such as carbohydrates, can also bind polyphenols,” said the researchers.