TY - JOUR
T1 - Syneresis in gels of highly ferulated arabinoxylans
T2 - characterization of covalent cross-linking, rheology, and microstructure
AU - Morales-Burgos, Ana M.
AU - Carvajal-millan, Elizabeth
AU - López-Franco, Yolanda L.
AU - Rascón-chu, Agustín
AU - Lizardi-mendoza, Jaime
AU - Sotelo-cruz, Norberto
AU - Brown-bojórquez, Francisco
AU - Burgara-estrella, Alexel
AU - Pedroza-montero, Martin
N1 - Publisher Copyright:
© 2017 by the authors.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - Arabinoxylans (AXs) with high ferulic acid (FA) content (7.18 μg/mg AXs) were cross-linked using laccase. Storage (G') modulus of AX solutions at 1%(AX-1) and 2%(AX-2) (w/v) registered maximum values of 409 Pa and 889 Pa at 180 min and 83 min, respectively. Atomic force microscopy revealed the grained and irregular surface of the AX-1 gel and the smoother surface without significant depressions of the AX-2 gel. Cured AX gels exhibited a liquid phase surrounding the samples indicating syneresis. The syneresis ratio percentage (%Rs) of the gels was registered over time reaching stabilization at 20 h. The %Rs was not significantly different between AX-1 (60.0%) and AX-2 (62.8%) gels. After 20 h of syneresis development, the dimers of the FA in the AX-1 and AX-2 gels significantly increased by 9%and 78%, respectively; moreover, the trimers of the FA in the AX-1 and AX-2 gels, by 94%and 300%, respectively. Scanning electron microscopy showed that, after syneresis stabilization, AX gels presented a more compact microstructure. Syneresis development in the gels of highly ferulated AXs could be related to the polymer network contraction due to the additional formation of dimers and trimers of the FA (cross-linking structures), which may act like a "zipping" process, increasing the polymer chains' connectivity.
AB - Arabinoxylans (AXs) with high ferulic acid (FA) content (7.18 μg/mg AXs) were cross-linked using laccase. Storage (G') modulus of AX solutions at 1%(AX-1) and 2%(AX-2) (w/v) registered maximum values of 409 Pa and 889 Pa at 180 min and 83 min, respectively. Atomic force microscopy revealed the grained and irregular surface of the AX-1 gel and the smoother surface without significant depressions of the AX-2 gel. Cured AX gels exhibited a liquid phase surrounding the samples indicating syneresis. The syneresis ratio percentage (%Rs) of the gels was registered over time reaching stabilization at 20 h. The %Rs was not significantly different between AX-1 (60.0%) and AX-2 (62.8%) gels. After 20 h of syneresis development, the dimers of the FA in the AX-1 and AX-2 gels significantly increased by 9%and 78%, respectively; moreover, the trimers of the FA in the AX-1 and AX-2 gels, by 94%and 300%, respectively. Scanning electron microscopy showed that, after syneresis stabilization, AX gels presented a more compact microstructure. Syneresis development in the gels of highly ferulated AXs could be related to the polymer network contraction due to the additional formation of dimers and trimers of the FA (cross-linking structures), which may act like a "zipping" process, increasing the polymer chains' connectivity.
KW - Arabinoxylan gel
KW - Ferulic acid
KW - Maize bran
KW - Syneresis
UR - http://www.scopus.com/inward/record.url?scp=85019165371&partnerID=8YFLogxK
U2 - 10.3390/polym9050164
DO - 10.3390/polym9050164
M3 - Artículo
SN - 2073-4360
VL - 9
JO - Polymers
JF - Polymers
IS - 5
M1 - 164
ER -