Tomáš Kopta

Quality changes in organic and conventional Hokkaido pumpkin (Cucurbita maxima Duch.) during storage

Abstract Organic production of vegetables has increased in recent years. Pumpkin is a well-known edible plant, which has substantial nutritional properties due to the presence of unique natural substances. Pumpkin is one of the most commonly grown organic vegetables in the Czech Republic. The aim of this work was to compare the quality of organic and conventional Hokkaido pumpkin (Cucurbita maxima Duch.) during storage in terms of colour changes (Lab colour space), loss of mass, concentrations of ascorbic acid and total carotenoid. BIO (from organic farming) and CONV (from conventional farming) variants were tested at monthly intervals over three (2013) and four (2014) months storage after harvest. In 2013, the average loss of mass reached 19% in BIO and 23% in CONV and in 2014 it reached 12% in BIO and 20% CONV. Differences of loss of mass between BIO and CONV were only significant in 2014. In all variants and in both years, a gradual reduction in ascorbic acid (AA) during storage was noted. The reduction in concentration of ascorbic acid (AA) was slower in BIO than in CONV variants, and in both years BIO variants also showed smaller changes in concentrations of total carotenoids compared to CONV variants. The BIO pumpkins maintained their red colour (a*) better during storage than the CONV pumpkins, but the evaluation of the total colour difference (TCD) showed significant differences over time in both variants in both years.