Elemental composition and bioaccessibility of three insufficiently studied Azorean macroalgae

The elemental composition and bioaccessibility of the Azorean macroalgaePetalonia binghamiae, Osmundea pinnatifidaandHalopteris scopariawere studied.H. scopariahad the highest Cr, Mn, Co and Ni contents. Iodine content was also the highest inH. scoparia, 1098 +/- 54 mg kg dw(-1). Content reductions due to rehydration were in the 75%-90% range. Steaming led to similar reductions with exception of Cr, Mn, Co, Ni and Zn inO. pinnatifida. ForP. binghamiaeandO. pinnatifida, bioaccessibility percentages varied between elements. Variation due to rehydration and culinary treatment was narrower, particularly forP. binghamiae. Whereas I bioaccessibility was low inO. pinnatifida, 11%-14%, it reached 57%-69% inP. binghamiae. On the basis of bioaccessibility, to meet the I DRI, 2.7 g driedP. binghamiae, 16.9-23.8 g rehydratedP. binghamiaeand 12.7 g steamedP. binghamiaeeveryday are required. ForO. pinnatifida, 5.0 g, 19.0-33.3 g and 12.9 g of dried, rehydrated and steamed red seaweed, respectively, are needed.