Modified Atmosphere Packaging of Prickly Pear Cactus Stems (Opuntia spp.)

The young, rapidly growing flattened stems or cladodes of the prickly pear cactus (Opuntia spp.), known in Spanish as `nopalitosʹ, are commonly consumed in Mexico as a vegetable, and are shown to reduce blood glucose levels. Nopalitos are very perishable with a storage life of 1 day at room temperature and 6 days when packaged in polyethylene bags and stored at 5°C. In our work we have tested the effect of packaging nopalitos at 5°C in modified atmospheres, where O2concentration was decreased to up to 8.6 kPa and CO2concentration was increased to up to 6.9 kPa, for up to 30 days. Modified atmosphere packaging significantly increased the storage life and decreased quality deterioration. It significantly decreased losses in texture, weight, chlorophyll content, crude fibre content and colour. Modified atmosphere packaging also decreased chlorophyllase activity, and caused the least increase in yeast and moulds, and total aerobic mesophiles counts, but slightly increased the total anaerobic mesophiles counts.