Acidic whey protein beverages are a growing component of the functional food and beverage market. These beverages are astringent, but astringency is an expected and desirable attribute of many beverages (red wine, tea, coffee) and may not necessarily be a negative attribute of acidic whey protein beverages. A study published in the Journal of Food Science aimed to define the consumer perception of astringency in clear acidic whey protein beverages.
First, the researchers held six focus groups to gain understanding of consumer knowledge of astringency. Consumers were presented with beverages and asked to map them based on astringent mouthfeel and liking. Orthonasal thresholds for whey protein isolate (WPI) in water and flavored model beverages were determined. Mouthfeel/basic taste thresholds were determined for WPI in water.
Next, acceptance tests on model beverages were conducted using 120 consumers with and without wearing nose clips. Consumers in focus groups were able to identify astringency in beverages. Astringency intensity was not directly related to dislike. Consumer acceptance of beverages containing WPI was lower when consumers were not wearing nose clips compared to acceptance scores of beverages when consumers were wearing nose clips. These results suggest that flavors contributed by WPI in acidic beverages are more objectionable than the astringent mouthfeel and that both flavor and astringency should be the focus of ongoing studies to improve the palatability of these products.