Harmful nitrogen as a criterion of beet quality

Harmful nitrogen represents the soluble nitrogen of sugar beet which cannot be eliminated during traditional juice purification (e.g. total nitrogen in thick juice). For this reason harmful nitrogen is an important criterion of beet quality. Using the recently developed pyro-chemiluminescence method harmful nitrogen can be determined in beet extracts clarified with aluminium sulphate as aluminum sulphate soluble nitrogen (AlN). In a first overview the harmful nitrogen content of sugar beet from a variety- and nitrogen fertilizer trial is presented. Harmful nitrogen, together with other beet constituents, is subsequently used for quality assessment after the presently applied quality criteria. In contrast to the usual amino-N analyses harmful nitrogen determinations by means of aluminum sulphate soluble nitrogen (AlN) will take into consideration this most important N-fraction of sugar beet in quality assessment and breeding for low nitrogen sugar beet varieties with sufficient alkalinity reserves.