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Formation of heat‐induced cottonseed congossypin( 7S ) fibrils at pH 2.0
Author(s) -
Zhou JianZhong,
Zhang Hui,
Yang HaiYan,
Wang Li,
Qian HaiFeng
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6517
Subject(s) - fibril , chemistry , thioflavin , congo red , monomer , protein aggregation , cottonseed , amyloid (mycology) , biophysics , dynamic light scattering , chemical engineering , biochemistry , adsorption , polymer , nanoparticle , organic chemistry , food science , inorganic chemistry , medicine , disease , pathology , biology , engineering , alzheimer's disease
Abstract BACKGROUND Heat‐induced protein aggregation is important for the texture of various food products. Many types of food proteins have been found to assemble into fibrillar structures under certain conditions. We studied fibril formation of cottonseed 7S storage protein upon heating (for 0–720 min) at 90°C and pH 2.0, investigated the conversion rate, and determined the extent of thermal aggregation . RESULTS Thioflavin‐T fluorescence and Congo‐red analysis indicated the formation of amyloid‐like fibrils upon heating. Centrifugal filtration indicated that the conversion was very low (<10%) until congossypin concentration up to 2 mg mL −1 , and the conversion increases with increasing heating time, but levels off after longer heating times. Dynamic light scattering and atomic force microscopy showed that the extent of thermal aggregation at pH 2.0, or contour length of the worm‐like and fine‐stranded aggregates, progressively increased with increasing heating time. Furthermore, reducing electrophoresis analyses indicated that progressive polypeptide hydrolysis occurred upon heating. Experiments indicate that congossypin can form heat‐induced amyloid‐like aggregates and the conversion of congossypin monomers into fibrils increased with heating time and protein concentration . CONCLUSION The results would be of vital importance for the utilisation of cottonseed proteins to produce thermally induced fibrillar gels with excellent properties. © 2013 Society of Chemical Industry