## 1 Introduction  
Brazil stands out for the immense biological diversity of its flora and is seen as one of the leading centers for the genetic diversity of fruit species worldwide. Although a wide variety of native fruit species is found in the Amazon and the Cerrado, the southern and southeastern regions also present a great richness in wild fruits. The Myrtaceae family stands out for designating the most significant number of species with food potential, which could be marketed in nature for use in the manufacturing of ice cream, juices, yogurts, liqueurs, desserts, cereal bars, jams, and jellies [1; 2; 3].  
The grumixameira is a native tree of the Brazilian Atlantic Forest. The fruit of the grumixameira, _Eugenia brasiliensis_ [PERSON], is approximately 2.0 cm in diameter. The skin is smooth, shiny, and has different colors [4; 5]. In Brazil, grumixama is commercially used for the production of jellies, pies, and liqueurs in the southern and southeastern regions [6], harvested between November and February, and can also be used in public gardens and ecological restoration programs [5; 7].  
The chemical and physical composition and polyphenol profile of grumixama can vary significantly due to the biome where the fruit is grown [5]. The main bioactive compounds present in fruits are phenolic compounds: mainly flavonoids and ellagitannins [8; 9] related to antib biofilm activity [4], the detection of quorum-sensing [10], and anti-inflammatory effects [6; 9]. In addition, its flavor characteristics are related to the presence of volatile organic compounds.  
Volatile compounds are substances released by foods that give off aromas and influence flavor [11; 12; 13; 14; 15], directly affecting consumer purchasing decisions. They arise from a complex mixture of secondary metabolites, including terpen, esters, aldehydes, ketones, and alcohols. terpenes, especially sesquiterpenes, have analgesic and antimicrobial properties [12; 16]. However, there is not much knowledge regarding these compounds in grumixama.  
Many extraction methods are used to analyze these substances, with an emphasis on solid-phase microextraction (SPME) [17; 18]. SPME is a technique that allows for low-cost, fast, solvent-free extraction, has an affinity for numerous analytes, and is easily coupled to gas chromatography [19; 20; 21]. The development of the HS-SPME VOC extraction method involves evaluating many parameters such as fiber type, agitation, extraction time, and temperature [17; 19; 21].  
For the analysis of separation and identification of these compounds, gas chromatography (GC) instruments coupled to mass spectrometry (MS) are used, preceded by the SPME technique, which consists of extracting volatile compounds through the fibers and transferring the material from the fibers through a chromatograph injector [8; 17; 22]. This extraction can vary according to the polarity of the extracting fiber and sample weight, as well as the time, and temperature of extraction, directly impacting the efficiency of the process. Knowledge of flavors and aromas is still a problem since the set of VOCs is specific for each species and fruit variety [8]. So, the determination of volatile compounds can contribute to the discovery of a new characteristic aroma of the species. The optimization of extraction processes is essential, as the SPME fiber coating material is crucial in obtaining a representative extraction of the volatile compounds profile [23].  
Given the above, the objective of this work is to evaluate the efficiency of different fibers of SPME in the extraction of volatile organic compounds from grumixama pulp and to optimize a method to determine the characteristic volatile profile of this fruit.