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Food Chemistry 2018
Journal of Food, Nutrition and Population Health
ISSN: 2577-0586
Page 100
July 23-24, 2018
Rome, Italy
3
rd
Edition of International Conference on
Agriculture &
Food Chemistry
J Food Nutr Popul Health 2018, Volume 2
DOI: 10.21767/2577-0586-C2-006
S
oy protein isolate (SPI) is an important source for preparing
fibrillar protein aggregates, which could be used in foods to
modify viscosity, flow behavior, and so on. Food processing often
involves pH adjustment and heat treatment, which would affect
the structure of fibrils, thus damaging their functional properties.
In this study, the structural changes of SPI fibrils with increasing
pH were monitored, and the method to improve the stability of
SPI fibrils was explored. In addition, the thermal aggregation
behaviors of the disaggregated SPI fibrils at different pH were
investigated. Thioflavin T fluorescence and circular dichroism
spectrum were used to characterize the content of cross β-sheet
in protein. The morphologies of SPI aggregates were observed
by TEM. The results showed that as the pH increased from 2 to
higher values, the flocculation appeared in SPI fibrils solution and
clusters of fibrilswere observed (pH3-6). Then the fibrils started to
disaggregate and finally disappeared (pH 7-10). The cross β-sheet
content of SPI fibrils started to decrease at pH higher than 6, and
showed huge losses at pH higher than 8. The addition of cationic
polymer could help stabilize SPI fibrils under pH ranging from 3 to
7. When the disaggregated SPI fibrils were heated, the peptides
from the original fibrils would generate small amorphous particles
(pH 7-10), large irregular agglomerates (pH 6), short and curved
worm-like aggregates (pH 3-5), and new fibrils (pH 2), respectively.
Both the worm-like aggregates and new fibrils had a lot of cross
β-sheet structure. This study would deepen our understanding of
self-assembly mechanisms for SPI and facilitate scientific design
of protein fibril-based food ingredients.
WYL123_good@163.comDisaggregation and re-formation of fibrils from soy protein
isolate: Effects of p
H
Yangling Wan
and
Shuntang Guo
China Agricultural University, China