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The bioaccessibility of Ca, Cu, Fe, Mg, Zn, and crude protein was evaluated after submitting beef, pork, and chicken to five different thermal treatments. The bioaccessibility of crude protein and metals were simulated by using in vitro enzymatic digestion with a gastric fluid solution and dialysability approach. Inductively coupled plasma optical spectrometry was used to quantify the dialyzable fraction and the total mineral content after microwave-assisted digestion. Graphite furnace atomic absorption spectrometry quantified Cu in chicken dialyzable fraction. The increase of temperature and heat exposure period decreased the protein bioaccessibility. Considering the total and dialyzable fraction, beef is an important source of Cu, Fe, Mg, and Zn to the human diet. The results of Fourier-transform infrared spectroscopy indicated physical changes in the treated samples related to protein denaturation, which was probably responsible for the decreased bioaccessibility of minerals and protein, mainly at higher temperatures.

a b s t r a c tA method using Laser Induced Breakdown Spectroscopy (LIBS) for calcium (Ca) determination in breakfast cereals was evaluated. To perform the calibration curve, seven commercial cereals containing Ca in a range of 16.00-3734 mg kg À1 were considered. The Ca amounts provided by the manufacturers were evaluated by using inductively coupled plasma optical emission spectrometry (ICP OES). The precision of the LIBS measurements was of 8% and the accuracy, observed by using a corn bran standard reference material was higher than 99%. The method was successfully applied to predict the Ca concentration in a set of commercial samples dispensing the sample pre-treatment, with the potential to be used in production lines.