EFFECTS OF INORGANIC CONTAMINANTS ON AÇAÍ ENDOPHYTIC PROBIOTIC MICROORGANISMS: AN APPROACH FOR THE SAFE CONSUMPTION OF FUNCTIONAL FOODS

The increased demand for health-beneficial functional foods in recent decades has driven research into probiotics. Endophytic microorganisms found in plants, such as the fruits of the açaí tree (Euterpe oleracea Mart.), have received special attention in this context. However, it is important to consider the presence of inorganic contaminants in the composition of açaí, as some of these contaminants can be toxic when consumed chronically, such as aluminum, nickel, lead and cadmium. Therefore, the aim of this study was to investigate the influence of Al3+, Ni2+ Pb3+ and Cd2+ on açaí endophytic probiotic microorganisms. Three bacterial strains were used: Pediococcus pentosaceus, Lactobacillus plantarum and L. rhamnosus. Minimum inhibitory concentration (MIC), 24-hour microbial growth curve using optical density (OD) and colony forming units (CFU) counts were evaluated. Result values were expressed as the mean ± standard deviation (SD) and the results of the means expressed as the value of cellular turbidity (absorbance value). The results showed that P. pentosaceus, L. plantarum and L. rhamnosus were able to grow in the presence of Al3+, Ni2+ and Pb2+ ions, while Cd2+ strongly inhibited the growth of all strains, at maximum and minimum concentrations, which was 0,207± 0.002-0,108±0.001, 0.189±0.003-0.152±0.5, 0.108±0.02-0.042±0.009 in P. pentosaceus, L. plantarum and L. rhamnosus strains, respectively. No significant differences were observed between the strains tested. P. pentosaceus showed slower growth in the presence of inorganic contaminants (P < 0.05), which indicates its toxicity. These results highlight the importance of investigating the presence of contaminants, such as inorganic contaminants, in functional foods containing probiotic microorganisms. This is especially relevant for açaí, a widely consumed and appreciated food. It is critical to assess food safety during the development of healthy foods.