TY - JOUR
T1 - Assessment of starch branching and lamellar structure in rice flours
AU - Van Leeuwen, Matthew Paul
AU - Toutounji, Michelle Rosemarie
AU - Mata, Jitendra
AU - Ward, Rachelle
AU - Gilbert, Elliot Paul
AU - Castignolles, Patrice
AU - Gaborieau, Marianne
PY - 2021
Y1 - 2021
N2 - Apparent amylose content is used to describe milled rice flour composition. This spectrophotometric method is often the only direct measurement of starch structure in routine quality analysis. However, starch exhibits 6 levels of structure. The (supra)molecular starch structure in rice flours was measured: average degree of branching by 1H NMR spectroscopy and semi-crystalline lamellar structure by small angle X-ray scattering (SAXS). The suitability of these methods in routine quality analysis for breeding programs or the food industry was assessed in terms of precision and accuracy. Determination of apparent amylose content exhibits high precision (ca 5 % error) but low accuracy. Determination of average degree of branching exhibits a similar precision but good accuracy. Sample preparation (dissolution) is the first source of error in 1H NMR spectroscopy and presumably also in spectrophotometry. Within narrow ranges of apparent amylose content (less than 2.5 % absolute difference) differences in average degree of branching and lamellar structure could be observed. The difference between chemical structures of different amyloses/amylopectins within a given sample is not negligible. This opens a way to explore how finer details of molecular and supramolecular starch structure can play a role in understanding rice quality.
AB - Apparent amylose content is used to describe milled rice flour composition. This spectrophotometric method is often the only direct measurement of starch structure in routine quality analysis. However, starch exhibits 6 levels of structure. The (supra)molecular starch structure in rice flours was measured: average degree of branching by 1H NMR spectroscopy and semi-crystalline lamellar structure by small angle X-ray scattering (SAXS). The suitability of these methods in routine quality analysis for breeding programs or the food industry was assessed in terms of precision and accuracy. Determination of apparent amylose content exhibits high precision (ca 5 % error) but low accuracy. Determination of average degree of branching exhibits a similar precision but good accuracy. Sample preparation (dissolution) is the first source of error in 1H NMR spectroscopy and presumably also in spectrophotometry. Within narrow ranges of apparent amylose content (less than 2.5 % absolute difference) differences in average degree of branching and lamellar structure could be observed. The difference between chemical structures of different amyloses/amylopectins within a given sample is not negligible. This opens a way to explore how finer details of molecular and supramolecular starch structure can play a role in understanding rice quality.
UR - https://hdl.handle.net/1959.7/uws:61063
U2 - 10.1016/j.foostr.2021.100201
DO - 10.1016/j.foostr.2021.100201
M3 - Article
SN - 2213-3291
VL - 29
JO - Food Structure
JF - Food Structure
M1 - 100201
ER -