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Amidons Lintnérisés Etudes chromatographique et enzymatique des résidus insolubles provenant de l'hydrolyse chlorhydrique d'amidons de céréales, en particulier de maïs cireux
Author(s) -
Robin Par J. P.,
Mercier C.,
Duprat F.,
Charbonniǵre R.,
Guilbot A.
Publication year - 1975
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.19750270204
Subject(s) - chemistry , pullulanase , amylose , hydrolysis , starch , size exclusion chromatography , enzymatic hydrolysis , acid hydrolysis , chromatography , sephadex , alpha amylase , retrogradation (starch) , amylase , enzyme , organic chemistry
Lintnerized Starches. Chromatographic and Enzymatic Studies of Insoluble Residues from Acid Hydrolysis of Various Cereal Starches, Particularly Waxy Maize Starch . Native cereal starches, particularly waxy maize starch, have been carefully hydrolyzed at 35°C with hydrochloric acid (2,2‐ N) in heterogeneous phase . Observation of the course of hydrolysis as a function of time makes it possible to classify the starches according to their acid lability. The kinetic values distinctly reveal two phases, i.e. a fast hydrolysis of the amorphous fraction and a slower degradation of the crystalline starch grain fraction. This observation was confirmed by X‐ray diffractometric patterns. The hydrolysis speed of acid resistant fractions seems to become slower as the apparent amylose ratio increases. The change in the macromolecular structure of the obtained granular residues or “lintnerized” starches as a function of time was examined after aqueous solubilization by means of gel chromatography using a calibrated Sephadex G‐50 column. Lintnerization causes a decrease in the apparent DP of the chains of the starch residues and two subgroups with apparent DP 13 and 25 appear rapidly. These DP are unchanging with time of acid treatment. The chromatographic and enzymatic studies of lintnerized starches were performed directly and after successive enzymatic digests with pullulanase and ß‐amylase. After debranching of solubilized residues with pullulanase and gel chromatography a linear chain subgroup of DP 15–20 appears. This one is in fact composed of two subgroups: one more important with a DP 13, the other broad distribution with a DP 15–25. The comparison with the subgroups observed before debranching shows that a main part of the initial subgroup of DP 25 could be considered as formed with singly branched chains. Furthermore a small proportion of pullulanase resistant ß‐limit dextrins was obtained. The obtained results permits one to suggest a new model for the structure of waxy maize amylopectin. On the basis of this model the differences in structure existing between the various starches are discussed and the results are compared with those reported elsewhere for potato starch. A parallelism between crystalline patterns of native starches and the amylopectin structure, particularly its branching degree, is observed.