Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy
This work explores the potential of confocal Raman microscopy to investigate the microstructure of mixed protein gel systems. Heat-set protein gels were prepared using whey protein isolate (WPI), soy protein isolate (SPI), and mixtures thereof, with a total of five different whey-to-soy protein rati...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-09-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/10/9/2179 |
| _version_ | 1797519314826297344 |
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| author | Laura G. Gómez-Mascaraque Samantha C. Pinho |
| author_facet | Laura G. Gómez-Mascaraque Samantha C. Pinho |
| author_sort | Laura G. Gómez-Mascaraque |
| collection | DOAJ |
| description | This work explores the potential of confocal Raman microscopy to investigate the microstructure of mixed protein gel systems. Heat-set protein gels were prepared using whey protein isolate (WPI), soy protein isolate (SPI), and mixtures thereof, with a total of five different whey-to-soy protein ratios (100, 75, 50, 25, and 0%). These were analysed using confocal Raman microscopy, and different data analysis approaches were used to maximize the amount of structural and compositional information extracted from the spectral datasets generated, including both univariate and multivariate analysis methods. Small spectral differences were found between pure WPI and SPI gels, mainly attributed to conformational differences (amide bands), but SPI exhibited considerably greater auto-fluorescence than WPI. The univariate analysis method allowed for a rapid microstructural analysis, successfully mapping the distribution of protein and water in the gels. The greater fluorescence of the capsule-like structures found in the mixed gels, compared to other regions rich in proteins, suggested that these may be enriched in soy proteins. Further analysis, using a multivariate approach, allowed us to distinguish proteins with different levels of hydration within the gels and to detect non-proteinaceous compounds. Raman microscopy proved to be particularly useful to detect the presence of residual lipids in protein gels. |
| first_indexed | 2024-03-10T07:41:06Z |
| format | Article |
| id | doaj.art-eada95c1cd754a00b8a155c039a89562 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-10T07:41:06Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-eada95c1cd754a00b8a155c039a895622023-11-22T13:05:31ZengMDPI AGFoods2304-81582021-09-01109217910.3390/foods10092179Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman MicroscopyLaura G. Gómez-Mascaraque0Samantha C. Pinho1Teagasc Food Research Centre, Food Chemistry & Technology Department, Moorepark, Fermoy, P61 C996 Cork, IrelandDepartment of Food Engineering, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, BrazilThis work explores the potential of confocal Raman microscopy to investigate the microstructure of mixed protein gel systems. Heat-set protein gels were prepared using whey protein isolate (WPI), soy protein isolate (SPI), and mixtures thereof, with a total of five different whey-to-soy protein ratios (100, 75, 50, 25, and 0%). These were analysed using confocal Raman microscopy, and different data analysis approaches were used to maximize the amount of structural and compositional information extracted from the spectral datasets generated, including both univariate and multivariate analysis methods. Small spectral differences were found between pure WPI and SPI gels, mainly attributed to conformational differences (amide bands), but SPI exhibited considerably greater auto-fluorescence than WPI. The univariate analysis method allowed for a rapid microstructural analysis, successfully mapping the distribution of protein and water in the gels. The greater fluorescence of the capsule-like structures found in the mixed gels, compared to other regions rich in proteins, suggested that these may be enriched in soy proteins. Further analysis, using a multivariate approach, allowed us to distinguish proteins with different levels of hydration within the gels and to detect non-proteinaceous compounds. Raman microscopy proved to be particularly useful to detect the presence of residual lipids in protein gels.https://www.mdpi.com/2304-8158/10/9/2179hyperspectral imagingmicroscopymicrostructurehydrogeldairyplant protein |
| spellingShingle | Laura G. Gómez-Mascaraque Samantha C. Pinho Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy Foods hyperspectral imaging microscopy microstructure hydrogel dairy plant protein |
| title | Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy |
| title_full | Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy |
| title_fullStr | Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy |
| title_full_unstemmed | Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy |
| title_short | Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy |
| title_sort | microstructural analysis of whey soy protein isolate mixed gels using confocal raman microscopy |
| topic | hyperspectral imaging microscopy microstructure hydrogel dairy plant protein |
| url | https://www.mdpi.com/2304-8158/10/9/2179 |
| work_keys_str_mv | AT lauraggomezmascaraque microstructuralanalysisofwheysoyproteinisolatemixedgelsusingconfocalramanmicroscopy AT samanthacpinho microstructuralanalysisofwheysoyproteinisolatemixedgelsusingconfocalramanmicroscopy |