Journal of Agricultural and Food Chemistry
Article
The protein and/or tannin selectivity was also verified
regardless of the saliva samples and tannin concentration tested.
The same group of salivary proteins yielded the higher number
of aggregates despite some salivary protein chromatographic
differences between samples. These results are in agreement
with previous studies because His was the group of proteins that
produced a higher number of aggregates when saliva was treated
with B3.17 Although His was the group of proteins that formed a
higher number of soluble B3−salivary protein aggregates studied
by mass spectrometry, it should be pointed out that Stath and
aPRPs were the more reactive groups of proteins and led to a
higher precipitation to form insoluble complexes.14,18
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Stability over time was also studied showing that the
B3−salivary protein aggregates evolved in time. After 1 h of
incubation, the trend was to decrease the molecular mass of the
B3−salivary protein aggregates. It is well-known that protein−
tannin noncovalent aggregation is a reversible process in aqueous
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ASSOCIATED CONTENT
* Supporting Information
FIA-ESI-MS spectra of human saliva protein and B3−human
saliva protein complexes as well as MALDI-TOF spectra
accuracy and sensibility. This material is available free of charge
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S
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saliva by mass spectrometry (MALDI-TOF-TOF and FIA-ESI-MS).
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Mateus, N.; Amado, F.; De Freitas, V. Reactivity of human salivary
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AUTHOR INFORMATION
Corresponding Author
*(V.D.F.) Phone: +351 220 402 558. Fax: 351 220 402 659.
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(19) Hagerman, A. E. Fifty years of polyphenol−protein complexes. In
Recent Advances in Polyphenol Researc, 1st ed.; Cheynier, V., Sarni-
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Funding
(20) De Freitas, V. A. P.; Mateus, N. Structural features of procyanidin
interactions with salivary proteins. J. Agric. Food Chem. 2001, 49, 940−
945.
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protein−tannin aggregates. J. Sci. Food Agric. 2001, 82, 113−119.
We thank the Fundacao para a Ciencia e Tecnologia (FCT),
̨
which funded this work by a postdoctoral fellowship (SFRH/
BPD/85293/2012) and by a research project grant (NORTE-
07-0162-FEDER-000048).
Notes
The authors declare no competing financial interest.
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dx.doi.org/10.1021/jf5033284 | J. Agric. Food Chem. 2014, 62, 10038−10045