This study aimed to optimize the extraction of bioactive compounds from the pulp, seeds, and leaves of grumixameira (Eugenia brasiliensis Lam.) and evaluate its antioxidant and cytotoxic effects for direct use in creamy cheeses for conservation purposes. Through the response surface methodology, the best mixtures of solvents (water:ethanol:acetone volume fractions) were identified for each plant part: pulp (0.42: 0.16: 0.42), leaves (0.49: 0.26: 0.25) and seeds (0.54: 0.30: 0.16); which promoted an increase in the yield of the extraction of bioactive compounds. Leaves extracts showed the greatest index of total phenolic content (187.03 mg GAE/g) and highest antioxidant activities through DPPH (486.55 mg Trolox/g) and FRAP (680.81 mg ferric sulfate/g) assays. The pulp extracts, in turn, presented the highest indexes of content of total flavonoids (20.17 mg QE/g) and total anthocyanins (62.32 cyanidin-3-glucoside/g). The high-performance liquid chromatography (HPLC) analyses identified quercetin as the major compound in all extracts, followed by catechin. The rutin also stood out in leaves and pulp extracts.The extracts obtained from the leaves and pulp of grumixama showed a low cytotoxic effect on human embryonic kidney cells. Using the three optimized extracts in creamy cheeses contributed to preserving the physical-chemical and microbiological characteristics, emphasizing the leaves extracts when used at a concentration of 2 wt %. Thus, the results obtained in this study demonstrated the bioactive potential of these natural extracts, which can be exploited for technological applications in the food and pharmaceutical industries.