Effects of low‐temperature blanching on tissue firmness and cell wall strengthening during sweet potato flour processing |
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| Authors: | Jiwen He Li Cheng Zhengbiao Gu Yan Hong Zhaofeng Li |
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| Affiliation: | 1. State Key Laboratory of Food Science and Technology, Jiangnan University, , 214122 Wuxi, Jiangsu, China;2. School of Food Science and Technology, Jiangnan University, , 214122 Wuxi, Jiangsu, China;3. Synergetic Innovation Center of Food Safety and Nutrition, , 214122 Wuxi, Jiangsu, China |
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| Abstract: | 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 Ca2+ 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%. |
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| Keywords: | Free starch rate low‐temperature blanching pectin methylesterase polygalacturonase sweet potato flour β ‐amylase |
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