The qualitative parameters of potato tubers in dependence on variety and duration of storage

Abstract

The qualitative parameters of the potatoes tubers may be significantly changed depending on the variety, group of ripening, way, regime, and duration of storage. So, these researches aimed to define the influence of the variety characteristics and duration storage on qualitative parameters of tuber potatoes. Five potato varieties of two ripening groups were used for testing: medium-early (Satina, Red Lady, Mozart) and medium-ripe (Aroza, Sifra). The chemical properties such as dry matters (DM), starch, sugars (total and reducing), crude protein (CP), ascorbic acid (AA), and nitrates content were determined before and after 2, 4, and 6 months of storage. DM lost during the storage of potato tubers, especially during the period from 4 to 6 months. The group of ripening did not influence this index. Potato tubers of all varieties had high starch content and the duration of storage had a light effect on the level of its losses. In the medium-early group, maximum changes of starch were 1% but in the medium-ripe – 1.9%. A strong effect on the quantities of total sugars (TS) had varietal characteristics of the potato but a group of ripening had light influence. The highest content of sugars was Satin (0.65%) and the smallest Sifra (0.22%) and Mozart (0.23%). After 6 months of storage content of TS depending on the variety increased from 2 till 5 times, while the reducing sugars (RS) increased at least five times and at the end of storage were 0.4% to 0.65%. The amount of AA and its losses during storage depended on the variety. The relative losses during the total storage period were 21.9% in the medium-early group and 28.1% in the medium-ripe. Influence ripening group on level changing AA was not detected. Nitrates' content did not exceed the maximum permissible level (250 mg.kg-1). Their quantities after 6 months were 47 – 61 mg.kg-1.

Effect of Storage Conditions on the Physicochemical and Processing Qualities of Different Potato Genotypes Grown in Eastern Uganda

“…The stored potato genotypes in all the ambient stores exhibited a general decrease in dry matter content. This decrease in dry matter content corresponds to the results of Davydenko [4] who reported a significant decreasing trend in the specific gravity and dry matter content of the potato tubers under storage. The variations observed show that potato dry matter content is likely to have been influenced by the genotypic make-up of the potato tubers as also reported in the studies by Mouhammed [18].…”

“…The quality of potato tubers is closely linked to the chemical characteristics of the tubers and it varies widely in relation to different factors such as growing conditions, variety, harvest time and means of storage [4,5]. Eastern Uganda is however characterized by poor pre-storage and in-storage practices for potato.…”