ABSTRACT
The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In the present work, we describe the PESI mass spectra obtained by in situ measurement of soybeans and several nuts (peanuts, walnuts, cashew nuts, macadamia nuts and almonds) using different solid needles as sampling probes. It was found that PESI-MS is a valuable approach for in situ lipid analysis of these seeds. The phospholipid and triacylglycerol PESI spectra of different nuts and soybean were compared by principal component analysis (PCA). PCA shows significant differences among the data of each family of seeds. Methanolic extracts of nuts and soybean were exposed to air and sunlight for several days. PESI mass spectra were recorded before and after the treatment. Along the aging of the oil (rancidification), the formation of oxidated species with variable number of hydroperoxide groups could be observed in the PESI spectra. The relative intensity of oxidated triacylglycerols signals increased with days of exposition. Monitoring sensitivity of PESI-MS was high. This method provides a fast, simple and sensitive technique for the analysis (detection and characterization) of lipids in seed tissue and degree of oxidation of the oil samples.
Subject(s)
Glycine max/chemistry , Juglans/chemistry , Nuts/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Arachis/chemistry , Macadamia/chemistry , Phospholipids/analysis , Phospholipids/chemistry , Principal Component Analysis , Spectrometry, Mass, Electrospray Ionization/instrumentation , Triglycerides/analysis , Triglycerides/chemistryABSTRACT
To verify the necessary storage time to reach maximum viability and the imbibition time of Macadamia integrifolia Maiden & Betche var. IAC-4-20) seeds, they were weighted and disposed in water vessels for the imbibition process, evaluated through weighing in intervals of 6 hours. It is concluded that the imbibition was maximum at about 90 hours after the beginning of imbibition. With relation to the analysis of viability, the seeds were planted monthly, during 12 months, after seed harvest. Maximum viability of seeds was reached four months after the initiation of seed storage.
O presente trabalho teve como objetivo, verificar o tempo de armazenamento necessário para que seja atingida a viabilidade máxima e o tempo de embebição máxima de sementes de macadâmia (Macadamia integrifolia Maiden & Betche var. IAC-4-20). As sementes foram pesadas e colocadas em recipientes com água para que ocorresse o processo da embebição, sendo realizada a pesagem a cada 6 horas. Pode-se concluir que a embebição foi máxima ao redor de 90 horas após o início da embebição. Para a análise da viabilidade das sementes, estas foram semeadas mensalmente, durante 12 meses a partir da colheita. Verificou-se que a viabilidade máxima das sementes é atingida, 4 meses após o início do armazenamento.
ABSTRACT
To verify the necessary storage time to reach maximum viability and the imbibition time of Macadamia integrifolia Maiden & Betche var. IAC-4-20) seeds, they were weighted and disposed in water vessels for the imbibition process, evaluated through weighing in intervals of 6 hours. It is concluded that the imbibition was maximum at about 90 hours after the beginning of imbibition. With relation to the analysis of viability, the seeds were planted monthly, during 12 months, after seed harvest. Maximum viability of seeds was reached four months after the initiation of seed storage.
O presente trabalho teve como objetivo, verificar o tempo de armazenamento necessário para que seja atingida a viabilidade máxima e o tempo de embebição máxima de sementes de macadâmia (Macadamia integrifolia Maiden & Betche var. IAC-4-20). As sementes foram pesadas e colocadas em recipientes com água para que ocorresse o processo da embebição, sendo realizada a pesagem a cada 6 horas. Pode-se concluir que a embebição foi máxima ao redor de 90 horas após o início da embebição. Para a análise da viabilidade das sementes, estas foram semeadas mensalmente, durante 12 meses a partir da colheita. Verificou-se que a viabilidade máxima das sementes é atingida, 4 meses após o início do armazenamento.