Metabolic activity and quality changes of whole and fresh-cut kohlrabi ( Brassica oleracea L. gongylodes group) stored under controlled atmospheres

Abstract

The effect of different controlled atmospheres (CA) on the metabolic activity and the quality of kohlrabi stems and slices was studied. Gas compositions of 5 kPa O 2 + 5 kPa CO 2, 5 kPa O 2 + 15 kPa CO 2, and 21 kPa O 2 + 0 kPa CO 2 (as control) were applied. Kohlrabi stems were stored for 28 days at 5 °C with 95% RH in CA followed by 3 days at 15 °C and 60–70% RH in air. Sliced kohlrabi was stored under the same gas compositions for 14 days at 5 °C. For both whole and fresh-cut kohlrabi, the respiration rates, ethylene production, sugar and organic acid contents, and sensory attributes (appearance, taste, and texture) were evaluated. The respiratory activity of whole and fresh-cut kohlrabi was quite similar. For slices, ethylene production decreased throughout storage. In stems and slices, storage at 5 kPa O 2 + 5 or 15 kPa CO 2 slightly delayed the decline in sugars and organic acids. For whole and fresh-cut kohlrabi, 5 kPa O 2 + 15 kPa CO 2 was the most appropriate gas composition to assure good commercial quality.