This study describes the validation of a headspace gas chromatography with flame ionization (HS-GC-FID) method for the determination of propanal, pentanal, hexanal, octanal, and trans-2-nonenal originated by lipid oxidation from cat food samples, as well as the evaluation of the matrix effect in the results. This method was applied to the analysis of commercial cat food and proved to be suitable for the determination of these volatile compounds in different samples. Mean recoveries between 88 and 109% were obtained and repeatability expressed as relative standard deviation was always lower than 6.95%. The intra- and inter-assay precisions ranged from 0.44 to 20.88% and from 0.45 to 20.52%, respectively. In addition, the matrix effect of cat food samples was determined by comparing the slopes of the standard addition method, and the external calibration curve and its influences were verified. These results highlight the high potential of this method, which allows the determination of lipid oxidation products in cat food samples directly, without requiring prior sample preparation techniques.

Acerola is a tropical fruit with a large industrial and commercial appeal due to its organoleptic qualities and bioactive compound-rich nature. Thus, as bioactive compounds (BC) stability is of great interest in the food industry, assessment of preserving techniques to prolong shelf life has become imperative. Hence, the purpose of this study was to evaluate how storage affects BC conservation in microencapsulated and lyophilized acerola pulps over 180 days. For this matter, antioxidant tests, physical-chemical analyzes, and vitamin C analysis by mass spectrometry were performed. Results indicated that microencapsulation better preserved the antioxidants in acerola pulp compared to the other preservation technologies employed. This is due to the greater BC concentration in the microencapsulated, as well as the pH reduction. Furthermore, over 180 days, microencapsulation better preserved the target compounds in acerola pulp compared to lyophilization, as evidenced by the superior content of BC in the former treatment, making it an appealing option for the food sector.

Considering the increasing number of low cost vegetable oil product adulterations, it is necessary to assess the authenticity of the lipid sources used in the dog food manufacture, consequently different brands and classifications of feed were analyzed to verify the product authenticity by gas chromatography (GC) with flame ionization detector (FID) and by electrospray ionization mass spectrometry (ESI-MS). Fatty acid (FA) composition analysis was performed to compare the FAs amount in samples with the respective guarantee levels stated by the manufacturers on its product label. Gas chromatography with flame ionization detector (GC-FID) results for omega-3 and 6 percentages are within the limits presented by each manufacturer, while the timnodonic + cervonic acids amount information presented on feed sample labels is not in accordance with GC-FID results. Consequently, the samples were analyzed by ESI-MS, the results exposed the chicken oil presence in the feed and eicosapentaenoic (EPA) + docosahexaenoic (DHA) acids absence, since no lipid profiles similar to fish oils or triacylglycerols (TAGs) containing these two FAs were found. Thus, the information presented on labels are in disagreement with the results obtained both by GC-FID FA composition analysis and by ESI-MS lipid profile analysis. Principal component analysis (PCA) confirmed that the main contribution was from FAs found by GC-FID.

Omega-3 fish oil supplements are widely consumed as source of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, presenting beneficial effects on human health. This study aimed to evaluate fifteen brands of omega-3 fish oil supplements available in Brazilian market in order to estimate the Brazilian reality regarding those supplements. Twelve fatty acids were quantified by gas chromatography with a flame ionization detector (GC-FID), and lipid profile were obtained via mass spectrometry fingerprinting using direct electrospray ionization mass spectrometry (ESI-MS) to assess the form in which fatty acids are present as well as the possible fraud existence. Among all analyzed samples, thirteen brands were revealed as EPA and DHA sources (90.2-440.3 and 77.8-302.3 mg g-1lipid, respectively) in triacylglycerols (TAG) or ethyl esters (EE) form. However, two brands were discovered with addition of large amounts of soybean oil, leading the final consumer to ingest this low-cost oil believing that they are consuming adequate doses of EPA and DHA.