1. Zinc fractionation in cow, goat, sheep and soybean milk samples using gel-electrophoresis and determination by electrothermal atomic absorption spectrometry (ETAAS)
- Author
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Márcia Cristina de Sena Oliveira, Pedro Vitoriano de Oliveira, Rodrigo Giglioti, Ana Rita A. Nogueira, C. M. Bossu, CARLA MAÍRA BOSSU, UFSCAR, RODRIGO GIGLIOTI, IZ, MARCIA CRISTINA DE SENA OLIVEIRA, CPPSE, PEDRO VITORIANO DE OLIVEIRA, USP, and ANA RITA DE ARAUJO NOGUEIRA, CPPSE.
- Subjects
Gel electrophoresis ,Chromatography ,Microwave oven ,Proteins ,food and beverages ,chemistry.chemical_element ,Fractionation ,Atomic spectroscopy ,Zinc ,law.invention ,lcsh:Chemistry ,Milk ,Certified reference materials ,lcsh:QD1-999 ,chemistry ,law ,Atomic absorption spectroscopy ,Sheep milk - Abstract
A screening method for zinc levels in different milk samples (raw cow, raw sheep, UHT cow, UHT goat and soybean milk base) was performed to establish the Zn levels' differences in protein samples. The samples were digested in a cavity microwave oven and the total Zn levels in the extracts were determined by flame absorption atomic spectrometry (FAAS). The protein separation was performed by urea polyacrylamide gel electrophoresis (UREA-PAGE). Protein bands were digested in the cavity microwave oven and Zn-protein analysis was further conducted by electrothermal atomic absorption spectrometry (ETAAS). The results showed that Zn is mainly bound to 32 kDa (b-casein) protein (17.0 ± 2.0%) in UHT cow and 24 kDa (a-casein) protein (9.0 ± 0.6%) in raw sheep milk. This method provided quantitative information regarding Zn species present in the protein fractions of the milk samples. The accuracy was evaluated using certified reference material (whole milk powder, NIST 8435) with statistically equivalent concentrations (Student's t-test) for total Zn and by addition and recovery experiments applied to measure Zn-protein. The recovered values were in the 92-110% range. Made available in DSpace on 2021-07-01T19:00:51Z (GMT). No. of bitstreams: 1 ZincFractionationCow.pdf: 300396 bytes, checksum: 9c0d5f6e765b2c9996705ff2bb985a87 (MD5) Previous issue date: 2021
- Published
- 2021