The effect of freezing time on the efficiency yield of potato starch hydrolysis by alpha-amylase

Authors
Elahe Abedi
Kiana Pourmohammadi
AssociateProfessor of Food Science and Technology, School of Agriculture, Fasa University, Fasa, Iran
10.22034/FSCT.19.128.183
Abstract
In order to achieve high-efficiency hydrolysis by α-amylase, freezing pretreatment of potato starch was performed at -25°C for 4 days (PF4) and 8 days (PF8). For this purpose, potato starch (NPS) and freeze pretreatment were suspended in water by exposure to alpha-amylase (0.15% w/v) for 10 hours at 25°C. Morphological properties, percentage of hydrolysis, degree of crystallinity by X-ray diffraction (X-ray) and pasting properties by rapid visco analyzer (RVA) were studied in native, freezed and hydrolyzed starches. Freezing caused surface damage of starch granule and according to the morphology results, scratches, dents and cracks were observed on the surface of the granule, and these changes were much more obvious after 8 days of freezing than after 4 days of freezing, and they were easily hydrolyzed. It was placed by α-amylase and caused the disruption of starch granules. The results of the hydrolysis percentage showed that freezing produced a trace percentage in the production of hydrolyzed starch. Hydrolysis percentage (%) of natural starch increased to 16.8%, 24.1% and 40.8% after hydrolysis in P, PF4 and PF8, respectively. In addition, the relative crystallinity after freezing decreased from natural starch (37.7%) to 34.8% in PF4 and 33.2% in PF8, and this decrease was very substantial (p˂ 0.05) after treatment with α-amylase which decreased to 34.3%, 29.4% and 25.5% in P, 4 days and 8 days of freezing, respectively. Gelatinization temperature and pick viscosity after amylase treatment in all natural starches under freezing treatment decreased significantly (p˂ 0.05) and the decreasing trend was observed in the order of PF8 > PF4 > P, which granular and intramolecular structures disruption as well as low swelling power could be the reason behind these results.
Keywords
Potato Starch
Freezing pretreatment
Crystallinity percentage
Morphological properties

Subjects

[1] K. Pourmohammadi, E. Abedi, The effect of pre and post-ultrasonication on the aggregation structure and physicochemical characteristics of tapioca starch containing sucrose, isomalt and maltodextrin, Int. J. Biol. Macromol. 163 (2020) 485–496.
[2] E. Abedi, K. Pourmohammadi, M. Jahromi, M. Niakousari, L. Torri, The effect of ultrasonic probe size for effective ultrasound-assisted pregelatinized starch, Food Bioprocess Technol. 12 (2019) 1852–1862.
[3] E. Abedi, K. Pourmohammadi, Aggregation behaviors of sonicated tapioca starch with various strengths of Hofmeister salts under pre-and post-ultrasonic treatment, Food Hydrocoll. 105 (2020) 105826.
[4] N.R. Jaafar, N.N. Nawawi, N.H. Abd Rahman, N.A.S. Annuar, R.A. Rahman, R.M. Illias, Synergistic action of cyclodextrin glucanotransferase and maltogenic amylase improves the bioconversion of starch to malto-oligosaccharides, Process Biochem. 103 (2021) 9–17.
[5] E. Abedi, M. Sayadi, K. Pourmohammadi, Effect of freezing-thawing pre-treatment on enzymatic modification of corn and potato starch treated with activated α-amylase: Investigation of functional properties, Food Hydrocoll. (2022) 107676.
[6] Y. Benavent-Gil, C.M. Rosell, Comparison of porous starches obtained from different enzyme types and levels, Carbohydr. Polym. 157 (2017) 533–540.
[7] Y. Benavent-Gil, C.M. Rosell, Morphological and physicochemical characterization of porous starches obtained from different botanical sources and amylolytic enzymes, Int. J. Biol. Macromol. 103 (2017) 587–595.
[8] X. Chen, L. Zhang, X. Li, Y. Qiao, Y. Zhang, Y. Zhao, J. Chen, X. Ye, Y. Huang, Z. Li, Impact of maltogenic α-amylase on the structure of potato starch and its retrogradation properties, Int. J. Biol. Macromol. 145 (2020) 325–331.
[9] S. Delatte, L. Doran, C. Blecker, G. De Mol, O. Roiseux, S. Gofflot, P. Malumba, Effect of pilot-scale steam treatment and endogenous alpha-amylase activity on wheat flour functional properties, J. Cereal Sci. 88 (2019) 38–46.
[10] M.T. Molina, A. Leiva, P. Bouchon, Examining the effect of freezing on starch gelatinization during heating at high rates using online in situ hot-stage video-microscopy and differential scanning calorimetry, Food Bioprod. Process. 100 (2016) 488–495.
[11] E. Abedi, K. Pourmohammadi, S. Abbasi, Dual-frequency ultrasound for ultrasonic-assisted esterification, Food Sci. Nutr. 7 (2019). https://doi.org/10.1002/fsn3.1115.
[12] X. Liu, L. Li, J. Yu, L. Copeland, S. Wang, S. Wang, In vitro digestibility of starches with different crystalline polymorphs at low α-amylase activity to substrate ratio, Food Chem. 349 (2021) 129170.
[13] J. Szymońska, F. Krok, E. Komorowska-Czepirska, K. Rębilas, Modification of granular potato starch by multiple deep-freezing and thawing, Carbohydr. Polym. 52 (2003) 1–10.
[14] S. Yu, Y. Zhang, H. Li, Y. Wang, C. Gong, X. Liu, X. Zheng, N.K. Kopparapu, Effect of freeze-thawing treatment on the microstructure and thermal properties of non-waxy corn starch granule, Starch/Staerke. 67 (2015) 989–1001. https://doi.org/10.1002/star.201500109.
[15] L. Guo, Y. Zhu, J. Li, Y. Gui, H. Tao, F. Zou, P. Liu, S. Janaswamy, B. Cui, The effects of wheat amylose ratios on the structural and physicochemical properties of waxy rice starch using branching enzyme and glucoamylase, Food Hydrocoll. 113 (2021) 106410.
[16] X. Han, H. Wen, Y. Luo, J. Yang, W. Xiao, X. Ji, J. Xie, Effects of α-amylase and glucoamylase on the characterization and function of maize porous starches, Food Hydrocoll. 116 (2021) 106661.
[17] J. Li, L. Li, J. Zhu, Y. Ai, Utilization of maltogenic α-amylase treatment to enhance the functional properties and reduce the digestibility of pulse starches, Food Hydrocoll. (2021) 106932.
[18] Z. Song, Y. Zhong, W. Tian, C. Zhang, A.R. Hansen, A. Blennow, W. Liang, D. Guo, Structural and functional characterizations of α-amylase-treated porous popcorn starch, Food Hydrocoll. 108 (2020) 105606.
[19] Y. Zhong, K. Herburger, J.J.K. Kirkensgaard, B. Khakimov, A.R. Hansen, A. Blennow, Sequential maltogenic α-amylase and branching enzyme treatment to modify granular corn starch, Food Hydrocoll. 120 (2021) 106904.