The study examines the effects of maltodextrins saccharified to various degrees on some rheological properties of potato starch dispersions. Pasting characteristics, flow curves, and mechanical spectra were determined for native potato starch and for its blends with potato maltodextrins having dextrose equivalents (DE) of 10.5, 18.4, and 26.5. The results showed that medium-saccharified maltodextrin (DE = 18.4) gave the strongest effect, manifesting itself as a considerable reduction in the viscosity at pasting, a decrease in apparent viscosity during flow, and a decrease in the storage and loss moduli. Addition of high-(DE = 26.5) or low-(DE = 10.5) saccharified maltodextrins had a markedly smaller effect on the rheological properties of starch. The differences in the effects produced by the maltodextrins are closely connected to the degree of polymerisation of the maltooligosaccharides in the systems. 1. Introduction Starch, one of the most common polysaccharides, has a number of specific properties that make it highly useful in the food industry and other sectors of the economy. It belongs to the cheapest thickening agents, texturizers, filling agents, and stabilizers. Heating starch granules in water environment causes them to paste. When they release amylose in the process, starch loses its specific granular structure [1–3]. The characteristic pasting temperature depends on botanical origin of starch as well as on the presence of other substances in the system. Sugars present in a starch suspension reduce the water activity of the system and stabilize the amorphous regions of the granules. As a result, starch pasting temperature increases and rheological properties of the system change [4–7]. The greater this effect, the higher the concentration of the solution and the greater the molecular weight of the substance added [3, 8, 9]. In the temperate climatic zone countries, such as Poland, potatoes are an important source of starch. Potato starch differs from cereal starches mainly in the size and structure of granules [10, 11], amylose content, phosphorus content, and manner of phosphorus bonding, as well as in fat and protein contents [1, 12–14]. Since natural properties of starch are not always advantageous in terms of technology and application, it is often subjected to various modifications, among them hydrolysis. Such a modification may produce maltodextrins, that is, carbohydrate polymers built of D-glucose units having a dextrose equivalent (DE) of under 20 [15, 16]. In Poland, starch hydrolysates with a DE of 20 to 30 are called
References
[1]
R. Parker and S. G. Ring, “Aspects of the physical chemistry of starch. Mini review,” Journal of Cereal Science, vol. 34, no. 1, pp. 1–17, 2001.
[2]
S. Lagarrigue, G. Alvarez, G. Cuvelier, and D. Flick, “Swelling kinetics of waxy maize and maize starches at high temperatures and heating rates,” Carbohydrate Polymers, vol. 73, no. 1, pp. 148–155, 2008.
[3]
N. Singh, N. Isono, S. Srichuwong, T. Noda, and K. Nishinari, “Structural, thermal and viscoelastic properties of potato starches,” Food Hydrocolloids, vol. 22, no. 6, pp. 979–988, 2008.
[4]
B. Abu-Jdayil, M. O. J. Azzam, and K. I. M. Al-Malah, “Effect of glucose and storage time on the viscosity of wheat starch dispersions,” Carbohydrate Polymers, vol. 46, no. 3, pp. 207–215, 2001.
[5]
P. A. Perry and A. M. Donald, “The effect of sugars on the gelatinisation of starch,” Carbohydrate Polymers, vol. 49, no. 2, pp. 155–165, 2002.
[6]
V. M. Acquarone and M. A. Rao, “Influence of sucrose on the rheology and granule size of cross-linked waxy maize starch dispersions heated at two temperatures,” Carbohydrate Polymers, vol. 51, no. 4, pp. 451–458, 2003.
[7]
P. J. Torley and F. van der Molen, “Gelatinization of starch in mixed sugar systems,” LWT—Food Science and Technology, vol. 38, no. 7, pp. 762–771, 2005.
[8]
D. Yoo and B. Yoo, “Rheology of rice starch-sucrose composites,” Starch—St？rke, vol. 57, no. 6, pp. 254–261, 2005.
[9]
D. Ga？kowska, “Effect of saccharides on gelatinization and retrogradation of modified potato starch,” Electronic Journal of Polish Agricultural Universities, vol. 11, no. 1, p. 19, 2008.
[10]
L. Juszczak, T. Fortuna, and F. Krok, “Non-contact atomic force microscopy of starch granules surface—part I: potato and tapioca starches,” Starch—St？rke, vol. 55, no. 1, pp. 1–7, 2003.
[11]
M. Sujka and J. Jamroz, “Starch granule porosity and its changes by means of amylolysis,” International Agrophysics, vol. 21, no. 1, pp. 107–113, 2007.
[12]
R. Hoover, “Composition, molecular structure, and physicochemical properties of tuber and root starches: a review,” Carbohydrate Polymers, vol. 45, no. 3, pp. 253–267, 2001.
[13]
N. Singh, J. Singh, L. Kaur, N. S. Sodhi, and B. S. Gill, “Morphological, thermal and rheological properties of starches from different botanical sources,” Food Chemistry, vol. 81, no. 2, pp. 219–231, 2003.
[14]
K. Pycia, L. Juszczak, D. Ga？kowska, and M. Witczak, “Physicochemical properties of starches obtained from Polish potato cultivars,” Starch—St？rke, vol. 64, no. 2, pp. 105–144, 2012.
[15]
I. S. Chronakis, “On the molecular characteristics, compositional properties, and structural-functional mechanisms of maltodextrins: a review,” Critical Reviews in Food Science and Nutrition, vol. 38, no. 7, pp. 599–637, 1998.
[16]
U. Uthumporn, I. S. M. Zaidul, and A. A. Karim, “Hydrolysis of granular starch at sub-gelatinization temperature using a mixture of amylolytic enzymes,” Food and Bioproducts Processing, vol. 88, no. 1, pp. 47–54, 2010.
[17]
A. L. M. Smits, P. H. Kruiskamp, J. J. G. van Soest, and J. F. G. Vliegenthart, “The influence of various small plasticisers and malto-oligosaccharides on the retrogradation of (partly) gelatinised starch,” Carbohydrate Polymers, vol. 51, no. 4, pp. 417–424, 2003.
[18]
Y. J. Wang and J. Jane, “Correlation between glass transition temperature and starch retrogradation in the presence of sugars an maltodextrins,” Cereal Chemistry, vol. 71, pp. 527–531, 1994.
[19]
E. Durán, A. León, B. Barber, and C. Benedito de Barber, “Effect of low molecular weight dextrins on gelatinization and retrogradation of starch,” European Food Research and Technology, vol. 212, no. 2, pp. 203–207, 2001.
[20]
J. A. Rojas, C. M. Rosell, and C. Benedito de Barber, “Role of maltodextrins in the staling of starch gels,” European Food Research and Technology, vol. 212, no. 3, pp. 364–368, 2001.
[21]
M. Witczak, J. Korus, R. Ziobro, and L. Juszczak, “The effects of maltodextrins on gluten-free dough and quality of bread,” Journal of Food Engineering, vol. 96, no. 2, pp. 258–265, 2010.
[22]
B. Wang, D. Li, L. J. Wang, and N. ？zkan, “Anti-thixotropic properties of waxy maize starch dispersions with different pasting conditions,” Carbohydrate Polymers, vol. 79, no. 4, pp. 1130–1139, 2010.
