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Comparative Acid Modification of Various Starches
Author(s) -
Singh Vasudeva,
Ali S. Zakiuddin
Publication year - 1987
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.19870391109
Subject(s) - sorghum , chemistry , food science , starch , legume , hydrolysis , agronomy , biology , biochemistry
Eight starches (maize, sorghum, finger millet, waxy and nonwaxy rice, chick pea, tapioca and potato) were acid modified with 0.5N HCl at 50°C. Alkali fluidity number (AFN) increased progressively with time of modification, and was highest in cereal followed by root, legume, and tuber starches. However, reduction in the number average molecular weight (M̄ n ) was in the reverse order. Potato starch had the highest M̄ n , among the nonwaxy native starches and showed the greatest fall upon modification, whereas cereal starches had the least M̄ n in native form and showed the least fall. In fact, there was a clear proportionality between the M̄ n , of native starch and the extent of its hydrolysis under any given set of conditions. This relationship could be expressed by two intersecting lines, one for grains and one for root and tuber starches. When acid modified starches were recovered and dried without neutralization, hydrolysis still continued strongly in potato starch and slightly in tapioca, finger millet and sorghum starches. Other starches showed no change.