Using phytochemicals to enhance health benefits of milk: impact of polyphenols on flavor profile.

The focus of new product development of functional foods is not only on the associated health benefits but also on the sensory properties of the finished product. A trained panel (n=13) assessed 5 milk-based beverages fortified with added apple or grape seed polyphenols and a control using descriptive analysis techniques. The resulting vocabulary consisted of 16 odor, taste, flavor, and mouthfeel attributes, complete with reference standards and scale intensities. Panelists differentiated between samples using all 16 attributes in the vocabulary (P<0.001). Samples fortified with polyphenols, sourced from grape seed and apple extracts, differed significantly. Bitterness and UHT (ultra-high temperature) odor and flavor were the key drivers of product difference. Relatively small (but still significant) differences were identified between those containing polyphenols from the same plant source but different suppliers. We concluded that both grape seed and apple polyphenols suppress the flavor characteristics of the milk, with apple polyphenols having more of an impact than grape seed polyphenols. In particular, the high level of bitterness in apple extracts has large flavor profile implications for product development.