The weight and processing quality of components of the storage roots of sugar beet (Beta vulgaris L)

Studies in the 1970s showed that sugar beet partitioned into root, crown an d scalp had large concentrations of impurities in the scalp, the root porti on had the best processing quality and the crown was intermediate. Since th en the processing quality of beet has improved. This paper reports similar studies on today's varieties, in an experiment at IACR-Broom's Earn over th e three years 1993-1995, and extended in 1996 to the most important soil ty pes used for sugar beet production in England. The crown is now a smaller p roportion of the total beet weight (70 compared to 130 g kg(-1)) but the di stribution of the concentrations of the quality parameters (sugar and the i mpurities potassium, sodium, amino nitrogen, raffinose, betaine and invert sugars) between the beet portions has not changed. This distribution was no t significantly affected by year, variety or beet size but was affected by soil type. Nitrogen-rich soils produced beet with heavier crowns and a smal ler differential in impurity concentration between the root and the crown. The scalp material had a variable sugar concentration, but it always contai ned large concentrations of impurities, especially invert sugar. The equati on of Pollach et al (Zucker industrie 116: 689-700 (1991)) which includes i nvert sugar as a variable, was applied to the data. It indicated that inclu ding all the crowns in the factory process with the roots would increase wh ite sugar yield by approximately 6%. The increase due to inclusion of the s calp was much smaller (2%), and would probably be expensive to achieve. (C) 1999 Society of Chemical Industry.