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In this work, the methylation method proposed by Hartman & Lago (1973), Figueiredo et al. (2016) (direct methylation) and International Organization for Standardization (ISO 5509, 1978) were evaluated in four different meat varieties (beef, pork, chicken and fish), comparing the results obtained by gas chromatography (GC) for verify the methylation method that presents the highest efficiency in this type of matrix. For all samples, the sum of fatty acids (SFA) was greater when applying direct methylation method, developed by Figueiredo et al., with values obtained of 111.50, 44.39, 31.50, 62.01 mg of FA per gram of sample respectively for meat samples beef, pork, chicken and fish. Direct methylation developed by Figueiredo et al., in addition to resulting in greater efficiency in the methylation of FA in meat samples, has several advantages when compared to other methods such as the use of smaller amounts of sample and solvents, less time to perform the analysis and less errors involved in the process, since methylation is carried out directly on the sample and does not require a lipid extraction process for subsequent methylation step. Neste trabalho foram avaliados os métodos de metilação propostos por Hartman & Lago (1973), Figueiredo et al. (2016) (metilação direta) e Organização Internacional para padronização (ISO 5509, 1978) aplicados em quatro variedades distintas de carnes (bovina, suína, frango e peixe), comparando-se os resultados de somatório de ácidos graxos totais (∑AG) obtidos por cromatografia em fase gasosa (CG) para verificar o método de metilação mais apropriado para este tipo de amostra. Para todas as amostras o somatório de ácidos graxos foi maior quando aplicado o método de metilação desenvolvido por Figueiredo et al., sendo os valores obtidos de 111,50, 44,39, 31,50, 62,01 mg de AG por grama de amostra respectivamente para as amostras de carne bovina, suína, frango e peixe. A metilação direta desenvolvida por Figueiredo et al., além de resultar em maior eficiência na metilação dos AG nas amostras de carne, apresenta várias vantagens quando comparada com as demais metodologias como, emprego de menores quantidades de amostra e solventes, menor tempo de realização da análise e menor quantidade de erros envolvidos no processo, uma vez que a metilação é realizada diretamente na amostra e não necessita de um processo de extração dos lipídios para posterior etapa de metilação.

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.

Fusarium oxysporum is usually found in foods such as corn, wheat, soybeans and barley, and can cause economic losses and risks to health in humans and animals due to the production of mycotoxins. The conventional microbiological test for fungal identification is based on morphological characteristics, requires specialists, and it is very time-consuming as it is necessary to carry out a culture of the fungus for two weeks before microorganism identification. Nowadays, researchers have made efforts to develop alternative analytical methods with advantages such as shorter time of analysis and better accuracy and reproducibility when compared to microbiological methods. In this way, in the present work, a qualitative analytical method to detect the secondary metabolites of Fusarium oxysporum in culture media by gas chromatography coupled to mass spectrometry (GC-MS) was developed with the intention of relating the presence of these chemical compounds to contamination by the fungus. The method comprised liquid-liquid or liquid-solid extractions with ethyl acetate from liquid and solid culture media, respectively, followed by GC-MS analysis, which was able to identify the presence of fusaric acid, 13-socosenamide, 5-(4-hydroxybutyl)-2-pyridinecarboxylic acid and toxin HT-2. The presence of these compounds was confirmed by high-performance liquid chromatography coupled to mass spectrometry quadrupole time of flight (HPLC-MS/QTOF).

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