The effect of soil-relationships and temperature on sensory and chemical quality parameters of carrots (Daucus carota L.)

Five carrot varieties were grown at two locations, 59 degrees 40'N and 69 degrees 39'N, on mineral and organic soil. The main variation of the samples was due to the effect of location as shown by means of Principal Component Analysis (PCA). Of the total variation 77% was explained by the first three principal components, the first component, explaining 51% of the total variation, was due to differences between the locations, mainly determined by different temperature and global radiation. The second component, explaining 17% of the total variation, could be related to variety and soil, the last different nutrition and water management. A third component, explaining 9% of the total variation was due to genetic variation. Carrots grown at the southern location showed higher sensory scores for colour attributes, bitter tasting, flavour components, higher carotene and sucrose content than at the northern location, where they showed highest sensory scores for whiteness, sweet taste and acidic taste, fructose and glucose content. Carrots grown at the northern location showed no significant differences between the soil types with respect to sensory attributes, chemical composition or morphological parameters, while carrots grown at the southern location showed significant differences between the soil types on sensory, chemical and morphological variables. Mineral soil grown carrots were in the south more firm and scored higher for earthy taste, and were more cylindrical in shape than carrots grown in organic soil. Using Partial Least Square regression analysis, variations in root weight and different root diameter expressions showed high explanations degrees due to the research assessors site and soil, and were closely correlated with certain sensory and chemical attributes.