Resumo:
The possible, effect of varying environmental conditions under wich coffee is grown, as well as the influence of different methods of coffee processing on niacin content and its variability in some cultivars, were determined in two sets of specially prepared samples of roasted coffee. In April 1958 four such samples were prepared: two belonging to the 'Bourbon Vermelho' cultivar (C 662) and two to the 'Bourbon Amarelo' one (Jaú). A single sample of each cultivar was taken from planta grown without shade of an experimental trial and another from shaded coffee plants of the same trial. It was found that the niacin content did not differ in both cultivars whereas the shading appears to have reduced the amount of niacin in both samples collected from shaded coffee trees. In November 1959, new samples were prepared from coffee plants of the cultivars 'Bourbon Vermelho' (LC 408), 'Mundo Novo' (LCP 379-19) and 'Bourbon Amarelo' (LCJ 30) grown under shaded and unshaded environments of the same trial. Some of the samples were from sun-dried cherries while others were from depulped coffee (dried in parchment). The shade again reduced the niacin content in all but one cultivar. The sample of the cultivar 'Bourbon Amarelo' (LCJ 30), showed higher niacin amount when obtained from shaded plants. It was also observed that the depulping operation gave higher amount of niacin although the increase was not so striking as that observed on samples from unshaded coffee. It is noteworthy that the latter three cultivars differ in niacin content, indicating that selection might be effective in isolating strains with higher amounts of this vitamin. The results indicate that in order to obtain reliable comparative results in the study of niacin content in coffee seeds, it is necessary to use samples colletcted from coffee trees grown under identical environmental conditions and also that samples be processed the same way.
