ESTIMATION OF THE ALKALINITY RESERVES OF SUGAR-BEET FROM THE ION BALANCE OF THICK JUICES

From the mean ion balance of thick juices recently published by Schiwe ck (1991) a relationship has been derived to evaluate the alkalinity r eserves of sugar beet (shortened ion balance): w'(IB) = 0.92 . w'(K+Na ) - (0.57 . w'(alphaN) + 1.9 . w'(In) + 2.9) mmol/100 g beet or - if i nvert sugar analyses are not available - with a constant average inver t sugar content of w(In) = 0.1 % on beet: w'(IB) = 0.92 . w'(K+Na) - 0 .57 . w'(alphaN) - 4.0. This relationship allows to calculate a limit (w(IB,0) for an equalized ion balance (i.e. for w(IB) = 0) from tareho use data of different sugar factories and campaigns and practical beet growing: w'(IB,0) for DELTAw'1 = w'(K+Na) - w'(alphaN) = 3.6 +/- 0.2 Thus, it is possible with insufficient alkalinity reserves (i.e. in th e case of surplus anions) to predict the approximate soda ash addition required for alkaline thick juices and to take into account the corre sponding amount of Na+-additon to the thin juice when assessing the qu ality of sugar beet (e.g. with the calculation of molasses sugar).