Desenvolvimento de métodos analíticos para determinação elementar e fração bioacessível em carnes à base de plantas por espectrometria de emissão óptica com plasma induzido por micro-ondas

Abstract

Meat analogues represent an alternative to animal meat consumption for people adopting a plant-based diet. Compared to red meat, plant-based meats have lower levels of total fat, saturated fat, and cholesterol. In addition, these products have a high fiber and protein content, and are often fortified with various micronutrients, such as vitamin B12, Fe, Zn, among others. Thus, studies reporting on the total and bioaccessible elemental concentration in plant-based meat samples are of utmost importance. Therefore, the aim of this study is to develop an acid decomposition method with a reflux system for the determination of Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Ti, and Zn using MicrowaveInduced Plasma Optical Emission Spectrometry (MIP OES) technique in raw and

cooked

plant-based meat samples prepared in oven and air fryer. The bioaccessible concentration for the samples cooked in the oven and the influence of cooking on the bioaccessibility of the determined analytes were also evaluated. The experimental conditions were optimized using a central composite design, in which the decomposition time, digestor block temperature, HNO 3 concentration, and H 2 O 2 volume were evaluated. The sample mass was fixed at 1.28 g, the volume of HNO 3 at 5 mL, and the addition of H 2 O 2 occurred in the last hour of decomposition. The responses utilized were the signal intensities of Ca, Fe, Mg, Mn, Na, Pb, Si, Ti, and the residual C content. The method accuracy was assessed using the certified reference materials NIST 1577b and NIST 1546, where no significant difference was observed between the certified and experimental values according to the Student's t-test at a 95% confidence level. For Al, B, Ba, Ni, Pb, Si, and Ti, the recovery tests ranged from 80 to 117%. Regarding total concentration, the highest values were found for Na, K, P, Ca, Mg, and Fe, while for Ni, all samples were below the limit of quantification. As observed from the analysis of variance and Tukey's test, cooking induced changes in the total and bioaccessible concentration of the observed analytes; the loss or addition of mineral content depends on factors related to cooking and the chemical composition of the samples. The bioaccessible fraction varied between 3.1 to 115% for samples cooked in the oven, with Al being the least bioaccessible element and K being the most bioaccessible, while for Pb, only one sample was above the limit of quantification. Therefore, the samples analyzed contribute to the intake of these analytes, but without exceeding the values recommended by regulatory agencies.