Descriptive and hedonic analyses of low-Phe food formulations containing corn (Zea mays) seedling roots: toward development of a dietary supplement for individuals with phenylketonuria

Abstract

Background: Seedling roots of anthocyanin-rich corn (Zea mays) cultivars contain high levels of phenylalanine ammonia lyase (PAL) activity. The development of a natural dietary supplement containing corn roots could provide the means to improve the restrictive diet of phenylketonuria (PKU) patients by increasing their tolerance to dietary phenylalanine (Phe). Therefore this research was undertaken to explore the sensory characteristics of roots of four corn cultivars as well as to develop and evaluate food products (cereal bar, beverage, jam-like spread) to which roots had been added.

Results: Sensory profiles of corn roots were investigated using ten trained judges. Roots of Japanese Striped corn seedlings were more bitter, pungent and astringent than those of white and yellow cultivars, while roots from the Blue Jade cultivar had a more pronounced earthy/mushroom aroma. Consumer research using 24 untrained panelists provided hedonic (degree-of-liking) assessments for products with and without roots (controls). The former had lower mean scores than the controls; however, the cereal bar had scores above 5 on the nine-point scale for all hedonic assessments compared with the other treated products.

Conclusion: By evaluating low-Phe food products containing corn roots, this research ascertained that the root-containing low-Phe cereal bar was an acceptable 'natural' dietary supplement for PKU-affected individuals.

Keywords: corn (Zea mays) roots; descriptive analysis; hedonic evaluations; phenylalanine ammonia lyase; phenylketonuria.