Enzymatic browning of potatoes is greatly reduced with organic fertilization compared to mineral fertilization

Summary in the original language of the document

Enzymatic browning of tubers owing to mechanical injury is assessed to indicate bad quality, mainly for visual reasons. Browning is also a serious problem during processing of potatoes. The effect of farmyard manure and mineral fertilization at three levels (50, 100, 150 kg total N per hectare) on darkening of potato extract was investigated in three years in a field trial. The extinction of the extract was measured at 400 nm for two days at three dates during the storage period from autumn to spring.
The extract of organically fertilized tubers hat a lower extinction compared to the mineral treatments. This difference occurred right at the beginning of the test with the fresh extract as well as during the following two days, when darkening continued with all samples, but with different extent. Whereas increasing manure levels reduced browning, higher amounts of mineral fertilizer intensified the dark colour. During storage from October to April the extinction showed no clear tendency. Polynomial regressions were calculated for the extinction values during the two days after production of the extracts. The R2 values decreased during storage from 0.95 - 0.98 in November to 0.80 - 0.91 in February. This may be interpreted as a hint of progressing disintegration.