In this work, a discussed and step-wise tutorial for LC-MS and GC-MS data processing using the open-access software MZMine2 is presented and discussed. The rationale behind each step was demonstrated to enable the readers to go through their own data and process it accordingly. The main lesson to be learned is that each parameter must be chosen in light of the raw data and no guidelines should suggest a predetermined value. Still, it is worth mentioning that ideal values for each parameter do not exist, and that the user might end up investing too much time futilely optimizing values. Our suggestion is to process your data in light of the raw data (and the study design) following the preview figure result and the resulting feature list generated in each processing step, interpret your data, and go back to process it again to tune the detection of important features.

Calystegines are nortropane alkaloids with three to five hydroxyl groups. These alkaloids are recognized as glycosidase inhibitors and thus may have therapeutic potential to be exploited. There are also reports of its possible toxic effects when they are present in foods. Commercial cultivars of human consumption in Brazil have been analyzed for calystegines content. Samples of Solanum tuberosum L. (potato), Ipomoea batatas L. (sweet potato), Solanum lycopersicum (tomato), Solanum melongena (eggplant) and Solanum aethiopicum L. (gilo) were obtained from local markets in Rio de Janeiro, RJ, Brazil. Qualitative analyzes were performed by gas chromatography coupled to mass spectrometry (GC/MS) and high performance liquid chromatography coupled to mass spectrometry (LC/MS). Gas chromatography with flame ionization detector (GC/FID) was used in quantitative analysis. Five calystegines (A3, B1, B2, B4 and C1) were detected in the whole sample set and the amounts of three of them were determined: A3 (1.94-15.88 mg kg-1); B2 (7.59-23.7 mg kg-1) and B4 (3.61-9.38 mg kg-1). This is the first report on the occurrence of these alkaloids in Solanum aethiopicum L.

Resumo Fundamento: A berinjela (Solanum melongena) é um fruto de consumo mundial. Seu processamento em forma de farinha é uma maneira de evitar perdas e aproveitar suas características nutricionais. Objetivos: Este estudo avaliou a composição físico-química (umidade, proteínas, lipídeos, fibra bruta, carboidratos, minerais, niacina, saponinas, acidez titulável, fibra alimentar e fenóis totais) da farinha de berinjela preparada a partir do fruto inteiro desidratado em estufa. Métodos: Avaliou-se a atividade antioxidante in vitro usando os seguintes ensaios: radical 2,2-difenil-1-picrilhidrazila (DPPH); poder antioxidante de redução do ferro (FRAP); e análise de polifenóis com Cromatografia Líquida de Alta Eficiência (CLAE - ácido clorogênico, ácido cafeico, ácido ferúlico e rutina). Resultados: Verificou-se a presença de: 23,09% de carboidratos; 13,34% de proteínas; 1,85% de lipídeos; 39,19% de fibras totais; 1.540 mg/100 g de compostos fenólicos solúveis totais; 840 mg/100 g de saponinas; minerais (potássio, magnésio, cobre, ferro, zinco, manganês); e niacina. Observou-se atividade antioxidante in vitro para DPPH (455,6 mg de ácido ascórbico/100 g) e FRAP (486,8 mg de ácido ascórbico/100 g). A CLAE determinou a presença de ácido ascórbico, tirosina e ácidos fenólicos (ácido clorogênico, ácido cafeico e ácido ferúlico). Conclusão: A farinha de berinjela tem alto teor de fibra além de bom teor de compostos fenólicos e saponinas com importante capacidade antioxidante observada através de ensaios in vitro. A farinha de berinjela é uma boa opção para ser adicionada à dieta da população, devido aos seus potenciais benefícios à saúde.

Abstract Background: The eggplant (Solanum melongena) is a fruit of world consumption. Its processing in the form of flour is a way to avoid losses and to take advantage of its nutritional characteristics. Objective: This study assessed the physicochemical composition (moisture, proteins, lipids, crude fiber, carbohydrates, minerals, niacin, saponins, titratable acidity, dietary fiber, and total phenols) of eggplant flour prepared from the whole fruit dehydrated in an oven. Methods: In vitro antioxidant activity was assessed using the following methods: 2.2-diphenyl-1-picrylhydrazyl radical (DPPH); Ferric Reducing/Antioxidant Power (FRAP); and analysis of polyphenols using HPLC (chlorogenic acid, caffeic acid, ferulic acid, and rutin). Results: It was possible to observe: 23.09% carbohydrates; 13.34% proteins; 1.85% lipids; 39.19% total fibers; 1,540 mg/100 g total soluble phenolic compounds; 840 mg/100 g saponins; minerals (potassium, magnesium, copper, iron, zinc, manganese); and niacin. In vitro antioxidant activity was observed through DPPH (455.6 mg ascorbic acid/100 g) and FRAP (486.8 mg ascorbic acid/100 g). The HPLC method determined the presence of ascorbic acid, tyrosine, and phenolic acids (chlorogenic acid, caffeic acid, and ferulic acid). Conclusion: The eggplant flour had great fiber content in addition to good content of phenolic compounds and saponins with important antioxidant capacity observed through in vitro assays. As a result, eggplant flour is a good addition to the diet of the population, since it can bring potential health benefits.

SPME-GC-MS, PCA and HCA multivariate techniques were used in order to evaluate their applicability to discriminate the three chemotypes (thymol, carvacrol and mixed) described for L. graveolens of Guatemala. The leaves of L. graveolens are used for treatment of colds, bronchitis, and as seasoning for food preparations, yielding essential oil up to 4.34 %. Leaves of 35 individuals from eight populations, and eight composite samples were analyzed using a DVB/Carboxen/PDMS fiber and GC-MS. PCA and HCA were carried out using eight markers (p-cymene, cis-sabinene hydrate, linalool, terpinen-4-ol, thymol, carvacrol, (E)-caryophyllene and caryophyllene oxide). The three chemotypes of L. graveolens were satisfactorily discriminated.

A cultura de girassol (Helianthus annuus L.) vem se consolidando no Brasil, pois se adapta a diversas regiões do país e apresenta características interessantes tanto do ponto de vista agronômico, quanto em relação à composição do óleo e à qualidade de sua proteína. O farelo desengordurado de girassol tem sido utilizado para ração, mas seu escurecimento limita o uso para consumo humano. O farelo contém ácido clorogênico, um potente antioxidante, que quando oxidado pela polifenoloxidase gera compostos que causam o escurecimento e reduzem a qualidade nutricional da proteína. Neste trabalho, foram obtidos extratos de ácido clorogênico, a partir do farelo desengordurado de girassol, utilizando-se metanol ou etanol como solvente, nas temperaturas de 25, 40 e 60°C e tempos de contato de 30 e 60 minutos, constituindo um experimento a três critérios de classificação. Houve diferença significativa entre solventes, tempo e temperaturas (P<0,05). A maior eficiência de remoção de ácido clorogênico foi de 40%, quando o metanol foi utilizado. Os extratos de ácido clorogênico obtidos têm potencial de uso como antioxidante.

The culture of sunflower (Helianthus annuus L.) has been consolidated in different regions of Brazil, and presents interesting characteristics on agronomic aspects, oil composition and protein quality. The defatted sunflower meal has been used to feed, but browning limits its use for human consumption. Sunflower meal contains chlorogenic acid, a potent antioxidant, which in turn is oxidized by polyphenol oxidase, producing compounds that darken the meal and reduce the nutritional quality of protein. In this research chlorogenic acid extracts were obtained from defatted sunflower meal, using methanol or ethanol as solvent, at temperatures of 25, 40 and 60°C and contact times of 30 and 60 minutes in a three classification criteria experiments. There were significant differences between solvent, time and temperature (P<0.05). The highest removal efficiency of chlorogenic acid was of 40%, when methanol was used. Chlorogenic acid extracts obtained have potential for use as antioxidant.