Caracterização de diferentes acessos de Myrciaria floribunda (H. West ex Willd.) O. Berg pelo perfil cromatográfico de voláteis

Abstract

Among the many native botanic families existing in Brazil, the Mirtaceae stand out for having a high economic potential, however, few are the explored species, as is the case of rumberry (Myrciaria floribunda). It is a native tree to the State of Alagoas, distributed in restingas areas, close to the South coastal region of the state. The fruits of this species have few studies that assess their chemical and biological potential. Thus, the acceptance of fruits by consumers is mainly related to sensory characteristics (taste, smell, texture, consistency and appearance), due to the fact that they present a very complex composition of volatile constituents directly involved in the quality of aroma and flavor, presenting odorous impacts. for the consumer. For the identification of these substances, several techniques are used, among which stands out the solid phase microextraction by headspace (SPME-HS) combined with gás chromatography with mass spectrometry (CG-MS). In the case of mass spectrometry (MS), the ionization stage is fundamental, which is why innovations with the technique have already been developed, such as ionization by Paper spray (PS), which allows the faster and simpler analysis of substances in complex matrices . In this context, the present work aimed at characterize fruits of different accessions of Myrciaria floribunda, highlighting mainly the composition of volatile substances, fixed compounds and antioxidant action. To this end, the work was divided into three chapters. Chapter I aimed to optimize the extraction conditions (time, temperature and agitation) by means of solid phase microextraction in headspace mode (HS-SPME) for the identification of volatile compounds (VOCs) from rumberry fruits (AC132). To this end, SPME fibers of polyacrylate (PA) and divinylbenzene / carboxen / polydimethylsiloxane (DVB / CAR / PDMS) were individually evaluated and compared. It was observed that the PA fiber had better performance, since it extracted a greater number of VOCs belonging to the class of hydrocarbon sesquiterpenes at temperatures above 85 ° C, for a time of 26 min and under agitation of 79 rpm. Chapter II aimed to characterize the fruits of different rumberry accessions differentiated by their orange (AC-67, AC-92, AC112, AC136, AC137, AC156), red (AC132, AC153) and purple (AC160) coloring and determine the volatile profile through the PA fiber through SPME-HS / GC-MS. For this, the fruit weight (PS), seed weight (PS), pulp weight (PP), number of seeds (NS), longitudinal (DL) and transversal (DT) diameter, shape, firmness, content was determined soluble solids, titratable acidity, ratio and pH. In general, rumberry fruits were characterized by being acidic. The orange-colored fruits (AC156) showed higher pulp yield, firmness (AC136), soluble solids (AC92) and ratio (AC137), while the red fruits were the ones with greater weight and dimensions (AC132), while the purple fruits presented low levels of titratable acidity (AC160). As for the volatile profile, the fruits present a greater umber of VOCs belonging to the sesquiterpenes group, with an emphasis on the orange- colored fruits because they presented the compounds patchoulene (32.9%), α-longipinene (24.9%), karyophylene (21.6% to 49.3 %) and γ-selinene (11.3% to 16.3%) as major constituents. Finally, chapter III aimed to characterize the fruits of the nine accessions of rumberry in terms of their physico-chemical properties, phenolic compounds, antioxidant activity and analysis of fixed compounds through mass spectrometry (MS) with ionization by paper spray (PS). For the physicochemical analysis of the fruits, samples of 128 fruits per Access were used. All accessions presented from one to two seeds per fruit. The AC132 and AC156 accessions showed larger fruits, while the AC137 accessions showed greater firmness and antioxidant activity (534.83 ± 137.68). The AC160 access fruits had a higher ratio and a higher total phenol content (279.01 ± 11.11). As for the chemical profile of the fruits, 32 compounds and 42 compounds in the negative ionization mode were identified in the positive ionization mode, thus highlighting the compounds belonging to the group of flavonoids. Therefore, the fruits of rumberry showed potential for their use as a functional food, since there were reports on the health benefits of bioactive compounds.