In vitro calcium bioaccessibility in raw and cooked cladodes of prickly pear cactus (Opuntia ficus-indica L. Miller)

The aim of this work was to determine the calcium bioaccessibility in Opuntia ficus indica L. Miller cultivars (Milpa Alta and Atlixco) and to evaluate the effect of cooking by using an in vitro digestion and dialysis method. The studied cladodes had a high content of calcium; however, only 16 and 9% of total calcium was dialyzable in Milpa Alta and Atlixco cultivars, respectively. The calcium dialyzability of Milpa Alta could be classified as medium level (10–19%) and Atlixco at the top of the rank assigned to low food dialyzability (<10%). Our results presented a significant negative correlation, between total oxalate and ionic dialyzable calcium (r = - 0.716, P ≤ 0.05). Milpa Alta could be a better source of calcium due to the higher bioaccessibility of ionic dialyzable calcium and lower total oxalate/calcium ratio. The cooking process did not affect significantly intestinal calcium bioaccessibility in any of the cultivars studied.