Distribution of dry matter and sugars within a tuber of potato cultivars grown under short day conditions*

Dry matter, reducing sugars and sucrose contents were determined, at harvest, in seven different parts of the tubers of processing cvs Kufri Chipsona-1, Kufri Chipsona-2, Kufri Jyoti, Kufri Lauvkar and Atlantic grown under short day conditions of North Indian plains. Significant distribution differences were observed for all the three parameters investigated. Dry matter content was highest in stem end and lowest in pith region. Kufri Chipsona-1 and Atlantic were the only cultivars with dry matter content of 17% or more in the pith region, making Kufri Chipsona-1 more suitable for preparation of French fries also. But, the imported French fries of Lambweston had relatively better distribution of dry matter content as compared to Kufri Chipsona-1. The reducing sugar and sucrose contents were greatest in stem end portions. The pattern of distribution of sugars, however, varied significantly with the cultivar. It is suggested that for the analysis of dry matter and sugar content in potatoes, sampling should be done in such a manner that all portions of the tuber, from stem end to bud end, are equally represented.