Evaluation of some potato cultivars for processing on the basis of their chemical composition*

Twelve potato cultivars were evaluated for processing on the basis of their chemical composition. Various constituents such as dry matter, starch, reducing, non-reducing and total sugars, true protein, free amino acids, total and orthodihydroxy phenols, tyrosine, ascorbic acid and betacarotene were analysed. Dry matter ranged from 15.4% (Gulmarg Special) to 24.2% (Kufri Dewa), whereas starch content varied from 12.3% (Gulmarg Special) to 18.9% (Kufri Dewa). There were significant differences in the content of sugars, total and orthodihydroxy phenols, true protein, free amino acids, tyrosine, ascorbic acid and beta carotene among varieties. Kufri Chandramukhi, Kufri Lauvkar, Kufri Bahar and Kufri Lalima were considered to be most suitable for processing into chips as they had more than 20% dry matter content with reducing sugars within permissible level (not more than 0.4% on fresh weight basis). Our small-scale chipping trials conducted with these four varieties produced chips of very good quality. Out of 4, Kufri Lalima gave maximum yield of deyhdrated chips. Gulmarg Special with lowest dry matter content was most suitable for canning. Kufri Jyoti showed maximum content of total phenols and was not considered to be suitable for canning and preparation of French fries and other dehydrated forms as it may show after-cooking darkening in the product. For high recovery of starch, cultlvars like Kufri Dewa and Kufri Chamatkar with high dry matter content should be preferred. From nutrition point of view, Kufri Dewa was considered the best as it showed maximum content of total carbohydrates and true protein which are the major chemical constituents of potato tubers.