Volatile organic compounds (VOCs) were isolated from acerola fruits (Malpighia emarginata D.C.), by means of different solid phase microextraction (SPME) fibers. For the extraction, the headspace SPME method was used, identifying the VOCs by gas chromatography (GC) with mass spectrometry (MS). The objective of this work was to evaluate the efficiency of SPME fibers and determine the best conditions for extracting VOCs from acerola fruit. The investigated conditions were: extraction time (20, 30 and 40 min), extraction temperature (25, 45 and 65 ºC) and agitation (0, 50 and 100 rpm). Of the evaluated fibers, polydimethylsiloxane (PDMS)/divinylbenzene (DVB) extracted the highest number of VOCs, most belonging to terpene, carboxylic acids and hydrocarbons. According to the investigated conditions, most compounds were obtained with an extraction time of 20 min, extraction temperature 65 ºC, and no agitation. Compounds cumene, o-xylene, thymol, m-cymene, o-cymene, 2-methyl-1,3-butadiene, anethol, 3-buten-2-one and methyl octadecanoic ester were responsible for the volatile profile of acerola.

INTRODUCTION: For at least a decade, a chronic kidney disease unassociated with diabetes mellitus, hypertension or any of the more common traditional causes, has been reported in Salvadoran agricultural communities. OBJECTIVE: Characterize histopathology of chronic kidney disease of unknown etiology in patients from Salvadoran agricultural communities, describe renal damage associated with each disease stage, and assess associations between histopathological alterations and sociodemographic variables. METHODS: The study involved 46 patients of both sexes, aged ≥18 years. After clinical, laboratory and imaging examinations, kidney biopsies were performed and renal tissue assessed for interstitial fibrosis, tubular atrophy, interstitial inflammatory infiltration, sclerosis, increase in glomerular size and extraglomerular vascular lesions (according to the Banff 97 classification used for kidney transplant rejection). Special staining was done: Schiff periodic acid, Masson trichrome and methenamine silver. Immunofluorescence techniques were used to evaluate IgA, IgG, IgM, complement C1q and C3, fibrin, and kappa and lambda light chain deposits. RESULTS: The main findings were interstitial fibrosis and tubular atrophy with or without inflammatory monocyte infiltration. In addition, generalized sclerosis, increased glomerular size, collapse of some glomerular tufts, and lesions of extraglomerular blood vessels (such as intimal proliferation and thickening and vacuolization of the tunica media) were observed. Interstitial fibrosis and glomerulosclerosis were associated with male sex. Sugarcane workers showed more interstitial fibrosis and tubular atrophy and less glomerulomegaly than other occupational groups. CONCLUSION: The morphological pattern in all biopsies was one of chronic tubulointerstitial nephropathy with secondary glomerular and vascular damage, in different stages of evolution of chronic kidney disease, independent of age, sex or occupation.