Solanine Glycoside of the pOtato. II. Its distribution in the potato plant

Abstract

The gencrnl probletn of preetlicting package perforrnnttcc cnn be illustrnted by the following example. The itnngiunry ninterial to be pncked is a wheat product which when pncketl ltas 10% moisture, and which begins to mildew a t 17%. The packets nre to be stored in nn ntniospltere of 96% 1Z.H. The niirtcrinl bulks 50 Ib. to thc bushel, nud is to be packed in pounds (413 g. oven-dry weight). 1 Ib. of the ninterinl would occupy about 530 c.c., so that n conveniently sized piickct would be 9 x 9 x 9 cui. I n calculnting the overall pcrnienbility of any pnckngc it is desirnble to niensiire X, Y, and Z for the niaterinls to IN used, under the conditions which are expected. ~Vlien the niensurenients nrc applied, however, to estimnte the side shelf-life of the pnckngc, n rensonahle safety factor must be uged to nllow for vnrintions ; so if it is not possible to innkc thc niensurcnients, nn upproxintntc rnluc may be ol)tained by using the results quoted above. I t is consitlcred thnt unclcr nonnnl conditions-no clraught, niotleriite tempcrnturc, humidities not cstreme-this \voiild incorporate n snfety fnctor of nl)out ten.If the pncknge is ntntle froin nioisturcproof cellulose filni, by Iientscnling, in tlie form of n 9-ciu. cube, the totnl area will be 6 x 0.092 or 0*0#36 sq. ni. Tlie heat-scnls will be in strips 6 nini. wide, aud the length niny be tnken as that of four sides of the packet, so thnt tlic nrea inodificd by heat-senling (p) is 4 x 0.09 x 0.006 or 0.00216 sq. in. Then by diffcrcncc the uiiultered men, a, is 041614 sq. ni. The length of the folds (8) is tltnt of 12 edges, or 1.08 nictres. From the rnlucs of Y and Z given nlrovc, S = 0.2, Y = 9 . 5 , and dey/nim. If the packet hnd beeu made from siiuilar film, but sealed with nn aillicsire seal 5 nitti. {ride, uitd inensuring 18 x 10 x 8 ctii., it can be estimntcd thnt 1' = 0.0097 + 0.0133 4-0.0017 = 0.0245 g./dny/ntni. KO figures nrc nrnilable yet for other wrnppiitgs, but if it isassumed that tlie overnll pernieal)ility is proportioual to the permeability of the plain wrapping, P for a 9-c1n. cubical packet made from waxed glnssinc would be 0.223 g./tlay/nini. Thc nbovu figures include n lprge safcty factor, but they itre 1111 calculated for cotuplctc exposure. In prncticc the packets would be stacked togctlier, nnd even the most exposed oncs-those at the corners-would only * This work WUII uridurhkcn ut tho mqocst of Dr. J. C. Drummotid, BcientMoAdviaor to tho Ministry of Food.

Comparison of Glycoalkaloid Content of Fresh and Freeze-Dried Potato Leaves Determined by HPLC and Colorimetry

“…Previously, large numbers of fresh potato leaves and tubers were analyzed for glycoalkaloid content by various methods to relate genetic variations in composition (Deahl et al, 1993;Lampitt et al, 1943;Morris and Petermann, 1985;Sanford et al, 1994;Tingey et al, 1978;van Gelder et al, 1989). The reported studies and the results described below suggest the need to further optimize and standardize analytical methods for potato glycoalkaloids McDonald, 1995b, 1996).…”

The Occurrence and Distribution of Free Alkaloid Solanidine in Netted Gem Potatoes

“…T o date, little or no thought has been given to the possibility that the burning sensation and ill effects resulting from the consumption of bitter potatoes (2,4,5,6) might be accentuated, if not directly caused, by the presence of free alkaloid solanidine. This alkaloid was reported to be present in senescent vines (7) and in actively growing young sprouts of certain potato varieties (8,9), but in no instance was it shown to exist in a free state in mature potato tubers.…”

Alkaloids in the human food chain – Natural occurrence and possible adverse effects

“…The average solanidine glycoside content of 521 samples of potato tubers was 73 mg/kg (range: 10–390 mg/kg) 158. Lampitt et al give an average of 25–100 mg/kg 159. The glycosides are usually concentrated in a 1.5 mm layer under the skin and peeling thus removes 50–95% of the GAs 158.…”