Consumer perception of astringency in clear acidic whey protein beverages.

Acidic whey protein beverages are a growing component of the functional food and beverage market. These beverages are also 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. The goal of this study was to define the consumer perception of astringency in clear acidic whey protein beverages. Six focus groups (n=49) were held 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 using a 7-series ascending forced choice method. Mouthfeel/basic taste thresholds were determined for WPI in water. Acceptance tests on model beverages were conducted using consumers (n=120) 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. The orthonasal threshold for WPI in water was lower (P < 0.05) than the mouthfeel/basic taste threshold of WPI in water. Consumer acceptance of beverages containing WPI was lower (P < 0.05) 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.