Sensory quality of turnip greens and turnip tops grown in northwestern Spain

Abstract

In Galicia (northwestern Spain), Brassica rapa var. rapa L. includes turnip greens and turnip tops as vegetable products that are characterized by a particular sulfurous aroma, pungent flavor, and a bitter taste. In this work, 12 local varieties grown as turnip greens and turnip tops were evaluated to define the sensory attributes, to relate them with secondary metabolites, and to select those sensorial traits that better describe these crops. Results showed differences in the sensory profiles of B. rapa varieties. Turnip greens were significantly different regarding aroma intensity, leaf color, and salty taste, while turnip tops were for color and firmness of leaves, moistness and fibrosity in mouth, sharpness, and bitter taste. Secondary metabolites as glucosinolates in turnip greens and phenolic compounds in turnip tops were highly correlated with texture and flavor. Glucosinolates, especially progoitrin (in turnip greens) and gluconapin (in turnip tops), showed correlation with bitter taste and aftertaste persistence. Correlation between sensory traits showed highest values between leaf firmness and stalk firmness (R = 0.94**), leaf firmness and fibrosity (R = 0.92**), aftertaste persistence and bitterness (R = 0.91**), and between bitterness and moistness (R = −0.89**).