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Functional Properties of Acid‐Thinned Potato Starch: Impact of Modification, Molecular Starch Characteristics, and Solution Preparation
Author(s) -
Ulbrich Marco,
Flöter Eckhard
Publication year - 2019
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.201900176
Subject(s) - starch , hydrolysis , solubility , viscosity , intrinsic viscosity , potato starch , molecular mass , materials science , slurry , chemistry , rheology , opacity , polymer , chemical engineering , organic chemistry , composite material , enzyme , engineering , physics , optics
A matrix of 27 acid‐thinned (AT) potato starch (PS) samples is prepared in a laboratory scale in slurry by gradation of the process parameters temperature (30, 40, and 50 °C), acid concentration (0.3, 0.6, and 0.9 m HCl) and time (4, 10, and 20 h), and is investigated in terms of functional properties (range of molar mass [ M w ] between 17.7 × 10 6 and 1.95 × 10 4 g mol −1 ). The solubility (S) increased basically with a higher degree of molecular degradation and disintegration temperature, and the viscosity decreased systematically with decreasing M w and increasing disintegration temperature. The existence of a specific M w range of the starch to achieve highest gel strength is proved. However, an impact of the molecular properties on the light transmittance ( T gel ) can be excluded, since all starch gels are opaque. A correlation between the strength and the specific non‐freezable bound water content ( w nf ) of the gels is found. High gel strength is accompanied by comparatively low w nf . In particular, the viscosity (processing) and the gel strength (final product characteristic), which are important technofunctional properties for the industrial application of AT starches, are found to be directly correlated to the M w of the starch product. Moreover, the latter is controllable by the hydrolysis process parameters.