A comparison of bioactive compounds of strawberry fruit from Europe affected by genotype and latitude

The effect of four different growing locations from Stjordal, Norway (63 degrees 36 ' N) to Conthey, Switzerland (46 degrees 12 ' N) on the composition of bioactives in strawberry (Fragaria x ananassa Duch.) of three genotypes (cvs Clery, Elsanta and Korona) was evaluated. Principal component analysis (PCA) was used to characterize differences in bioactives between genotypes within a location. Despite harvest period and year-to-year effects, a clear clustering related to the effects of the cultivars was shown. Furthermore, PCA was able to separate locations within a cultivar due to differences in bioactive compounds and this effect was stronger than local variations by temporary weather changes or even year-to-year effects. As a result, the northern samples had principally lower anthocyanin amounts than the southern ones and, moreover, distribution of individual anthocyanins was different. In contrast, the content of vitamin C and the antioxidant capacity (TEAC, ORAC, total phenols) was generally increased with higher latitudes calculated on a fresh weight basis. Results of proanthocyanidins and individual polyphenols detected by high performance liquid chromatography indicated that the higher contents were mainly due to tannin-related components. For all these observations, cultivars responded in general similarly. A North-South division was identified but no clear trend towards latitude could be recorded, mainly since one major impact factor for the biosynthesis of phenolics and ascorbic acid is temperature, which is altering not only by latitude, but also by the shift of the harvest period and the current weather conditions prior to harvest. In conclusion, genetic effects were generally stronger than environmental effects.