Effect of atmosphere composition on the quality of ready-to-use broccoli raab (Brassica rapa L.)

BACKGROUND: Many leafy brassicas are widely used for ready-to-use salads. Broccoli raab (Brassica rapa L.), also called turnip top, or rapini, is extensively cultivated in southern Italy. The edible portion is made up of the green, immature inflorescences and the stem with its most tender leaves. Recently, interest in this crop has increased among European consumers; moreover, a substantial increase in consumption could come from the ready-to-use product. RESULTS: The effects of four different atmosphere compositions (air, 3% O-2 in nitrogen, 3% O-2 + 10% CO2 in air, and 10% CO2 in air) on quality attributes of ready-to-use broccoli raab were studied. Controlled atmosphere affected appearance, composition, respiration rate, weight loss, and presence of off-odours. Storage of broccoli raab florets under low oxygen conditions delayed post-cutting deterioration during storage at 5 degrees C and preserved appearance and typical odour, up to 17 days. Moreover, respiration rate as well as loss of green colour, chlorophyll and vitamin C were also slowed down in this condition. Finally, in this study no effect of controlled atmosphere storage was found on total phenols content and antioxidant activity. CONCLUSION: Results showed that cold storage in 3% O-2 can be beneficial in order to maintain quality of ready-to-use, broccoli raab for up to 17 days. (C) 2010 Society of Chemical Industry