Carbohydrate composition and content of organic acids in fresh and stored apples

The contents of low-molecular-weight carbohydrates (LMWC; sorbitol, glucose , fructose and sucrose), starch, dietary fibre and organic acids were deter mined in seven apple cultivars at the start and end of the consumption inte rval. The cultivars included were Summered, Aroma, Ingrid Marie, Cox Orange , Mutzu, Belie de Boskoop and Jonagold. The total content of LMWC ranged be tween 615 and 716 g kg(-1) dry matter (DM). The dominating sugar was fructo se, corresponding to on average 57% (range 48-62%) of the total LMWC. Howev er, in Cox Orange the sucrose content was considerably higher and the fruct ose and sucrose contents constituted approximately 46% each. Total dietary fibre content was similar in the cultivars (total dietary fibre 160 +/- 20 g kg(-1) DM), except for Belie de Boskoop which had a higher content (203 g kg(-1) DM). Mutzu had a lower proportion of soluble fibre (27% of total di etary fibre) compared with the others (mean 32%). The organic acid content was on average 80 +/- 3 g kg(-1) DM, except for two of the cultivars (Summe red and Belie de Boskoop) which had a higher content (105 +/- 6 g kg(-1) DM ). Interestingly, the organic acid content was only slightly reduced upon s torage in the case of Belle de Boskoop, whereas there was a substantial dec rease in all the other cultivars (p<0.001). Sucrose (p<0.01) and starch (p< 0.05) contents decreased in all cultivars following storage, whereas sorbit ol (p<0.05) and total dietary fibre (p<0.05) contents increased. It is conc luded that the observed differences in composition are of such magnitude th at they may affect both nutritional and sensory properties. (C) 2000 Societ y of Chemical Industry.