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Effects of low‐temperature blanching on tissue firmness and cell wall strengthening during sweet potato flour processing
Author(s) -
He Jiwen,
Cheng Li,
Gu Zhengbiao,
Hong Yan,
Li Zhaofeng
Publication year - 2014
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/ijfs.12437
Subject(s) - blanching , pectin , pectinase , chemistry , food science , starch , amylase , cell wall , starch gelatinization , enzyme , biochemistry
Summary Free starch rate has been one of the most important criterions to evaluate the quality of sweet potato flour. Low‐temperature blanching ( LTB ) of sweet potatoes before steam cooking has shown significant increase in tissue firmness and cell wall strengthening. This research indicated that pectin methylesterase ( PME ) activity decreased by 87.8% after 30 min of blanching in water at 60 °C, while polygalacturonase ( PG ) and β‐amylase activity decreased 69.4% and 7.44%, respectively, under the same condition. Both PME and β‐amylase played important roles in tissue firmness. Further studies of tissue firmness and methyl esterification showed that the combination of LTB and Ca 2+ could increase the activity of PME and significantly enhance the pectin gel hardness to strengthen the cell walls and decrease free starch rate from 12.83% to 7.28%.