Calculation of the nonsugar mass in thick juice from beet analyses  - Proposal of a formula to assess the technical quality of sugar beet.

H. Schiweck, G. Kozianowski, J. Anderlei and M. Burba Zuckerindustrie (1994), pp. 268-282 (German).

The 3rd term has been lost ....

This article is well written and can be easily understood. This has enabled me to spot an error, which has an impact on the summarized formula and was subsequently used in the sugar technology book without correction. To avoid the copying of a wrong factor in the future, I would like to point out the following:

On page 276 a linear regression is given for an estimation of the Kjeldahl-N in thick-juice (w'KjN,DiS) from alpha-aminoacid-nitrogen in beet (w'αN):
	w'KjN,DiS = 2.056 * w'αN + 5.447     (r=0.961)
On page 277, equation (4), the mass of nitrogen-compounds is calculated from this regression by multiplying it with the "Kjeldahl-equivalent-weight" 139.9:
	mNh on beet = (2.056 * w'αN + 5.447) * 139.9
On page 277 in formula (5) the preceding formulas (3) and (4) are added up correctly:
	Calculated mass of nonsugar on beet = + 0.85 * 1.08 * 36.0 * w'K+Na + 0.85 * 1.08 * 62.3 * w'K+Na -  0.60 * 0.95 * 62.3 * w'αN + (2.056 * w'αN + 5.477) * 139.9
	where 0.85 is the degree of extraction of alkalis 1.08 is an assumption of 8% ½moles of Ca on moles of alkalis 36 is the cation "equivalent weight" from Table 7 62.3 is the nitrogen-free anion "equivalent weight" from Table 7 0.60 is the share of anions per αN-compounds 0.95 is the degree of extraction of αN-compounds.
But: the negative term -0.6 * 0.95 * 62.3 * w'αN was lost on the way from formula (5) to the summarized formula (5a) and therefore the factor 288 in this formula does not correspond to the preceding explanation. According to the explanation of the authors this value should be replaced by 252. The wrong factor 288 has already been carried over to Table 3/10 of the new sugar technology book and there is some danger that in the future authors will quote the wrong value again and again. The high quality of the paper enabled me to check the formulas and spot this error. The corrected value corresponds to the preceding explanation of the authors and could be used for comparison of formulas in the future. NB: I want to point out that I disagree with methods like this, based on one average only, instead of a low and a high value "group average".

2003-12-01       G. Pollach