Influence of storage conditions on the quality attributes of potato tubers with purple flesh

Abstract

This study was conducted to analyze the effects of controlled atmosphere storage on quality attributes of potato tubers with purple fleshed (cv. ‘Vitelotte’). Potato tubers with purple-fleshed can be a major source of natural antioxidants, which have a beneficial effect on human health. They contain biologically active compounds such as phenolic compounds, ascorbic acid, tocopherol and selenium. ‘Vitelotte’ tubers were stored 20 weeks under two different controlled atmosphere combinations at 5 ± 1 °C (relative humidity – 95%). The experiment included two factors: I – tubers storage time in weeks (five treatments: 4, 8, 12, 16, 20 weeks); II – different gas composition in controlled atmosphere chambers (two treatments: No. 1 - O2 – 21%, N2 – 78.5%, CO2 – 0.5% and No. 2 - O2 – 3.6%, N2 – 87%, CO2 – 9.4%). The amounts of dry matter, soluble solids, crude ash, crude fibre and natural weight loss were established in tubers after harvesting and during storage. The amount of dry matter was determined by drying samples at temperature of 105°C until the constant weight. Soluble solids content was determined by the refractometric method. Contents of crude ash and crude fiber were determined according to the method of Heneberg-Shtoman. Natural weight losses were assessed and estimated before and after the storage. The results obtained showed that the changes in compositional parameters of potato tubers during the storage period was dependent upon gas composition and storage period. The contents of dry matter, soluble solids as well as crude ash of Vitelotte tubers increases during storage in controlled atmosphere chambers. The highest increase in dry matter and crude ash content was in chamber No. 2 after sixteen and twenty weeks of storage