Sensory evaluation of gluten-free fresh pasta from proso millet

Despite being gluten-free and exhibiting favorable agronomic properties, millet is underutilized in North America and Europe. To promote its use in food products, we previously reported on the suitability of proso millet for preparation of gluten-free pasta, focusing on cooking quality, compositional and nutritional aspects. The aim of this study was to gain insight into consumer evaluation of pasta, and relate compositional attributes to sensory perception. Fettuccine-type fresh pasta was prepared from four millet varieties with different amylose content (from 7.8% to 35.7%) and prolamin profile. Samples were compared to two commercial fettuccine products, one wheat-based, and the other gluten-free. Freshly cooked samples were evaluated by a sensory panel trained on descriptive analysis . Data were analyzed via ANOVA, Student-Neuman-Keuls tests, and principal component analysis that included instrumental data as supplementary variables. Several attributes related to appearance, taste and texture differed significantly among samples. One millet pasta (from variety Earlybird) was ranked as more yellow than the commercial gluten-free pasta, but not different in yellowness to wheat; all other millet varieties resulted in pasta that was rated more yellow than commercial gluten-free, but less yellow than wheat pasta. This assessment is in agreement with instrumental analysis of carotenoids via HPLC and color via chromameter. All millet samples were perceived as more uniform, but also more gray than commercial samples. Regarding taste, Earlybird millet pasta received higher bitterness and bitterness aftertaste scores than other millet and commercial samples. In terms of texture, millet pasta was significantly starchier, less elastic and grainier than both commercial samples. The presence of high molecular weight prolamins corresponded to lower perceived stickiness, but higher graininess. Higher amylose contents increased firmness and chewiness, but reduced stickiness. Earlybird millet pasta was significantly stickier, but less chewy and firm than all other samples, in agreement with low instrumental firmness. Principle component analysis differentiated commercial samples from millet pasta, as well as Earlybird pasta from other millet samples. Earlybird and wheat pasta were characterized by high yellowness, low firmness and low chewiness; the other millet samples were of intermediate yellowness and firmness, and commercial GF pasta exhibited high firmness and low yellowness. Graininess, starchiness, and uniformity were characteristic for all millet pasta; high tensile strength and elasticity were characteristic for both commercial controls. Our study reveals which attributes distinguished millet from commercial pasta, and highlights parameters that warrant improvement by recipe or processing optimization. Learning objectives • Key attributes that distinguish fettuccine-type millet pasta from commercial gluten-free and wheat pasta • Influence of amylose and prolamin profile on sensory outcomes • Relation of instrumental to sensorial characterization of fresh pasta