Carbohydrate Polymers 94 (2013) 193–198 Contents lists available at SciVerse ScienceDirect Carbohydrate Polymers jo u rn al hom epa ge: www.elsevier.com/locate/carbpol Effect of preparation method on the properties of potato starch acetates with an equal degree of substitution  T. Zi˛ eba a , M. Kapelko a,∗ , A. Szumny b a Department of Food Storage and Technology, Wrocław University of Environmental and Life Science, Chełmo´ nskiego 37/41, 51 – 630 Wrocław, Poland b Department of Chemistry, Wrocław University of Environmental and Life Science, C. K. Norwida 25/27, 50 – 375 Wrocław, Poland a r t i c l e i n f o Article history: Received 4 November 2012 Received in revised form 20 December 2012 Accepted 1 January 2013 Available online 20 January 2013 Keywords: Potato starch Resistant starch Retrogradation Acetylation a b s t r a c t Acetylated retrograded starch is one of the forms of resistant starch (RS3/4). Apart from the known resistance to amylolysis, it is characterized by the capability to form viscous pastes. Properties of this type of acetates are mainly determined by the degree of substitution and raw material used for esterification. The objective of this study was to produce starch acetates with a degree of substitution DS = 0.1 from native potato starch and retrograded potato starch, and to compare selected properties of the resultant preparations. Retrograded starch was produced by freezing pastes with concentrations of 1, 4, 10, 18 or 30 g/100 g. Starch acetates with a degree of substitution DS ∼ 0.1 were produced from native or retrograded starch through acetylation with various doses of acetic acid anhydride (6.5–26.0 cm 3 /100 g of starch). The prepa- rations produced were characterized by various properties. A positive correlation was observed between resistance to amylolysis and the number of acetyl groups at C2 and C3 the produced starch acetates. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Starch – as one the most abundant polysaccharides in nature – has been widely applied in both the food and non-food indus- tries. Yet, in its native form starch has low industrial applicability. Depending on demands and mode of utilization, most of the starch produced is subjected to successive physical and chem- ical modifications. These modifications enable obtaining starch preparations with different structure and properties. The change of starch structure by means of physical and chemical modifications may affect a decrease in its susceptibility to amylolytic degrada- tion. One of the groups of modified preparations used in recent years as food additives includes preparations of resistant starch that have been reported to play a health-promoting role (Laguna, Salvador, Sanz, & Fiszman, 2011; Perera, Meda, & Tyler, 2010), as the so-called prebiotics (Angioloni & Collar, 2011; Scarminio, Fruet, Witaicenis, Rall, & Di Stasi, 2012). One of the forms of resis- tant starch is retrograded starch (RS3) produced as a result of physical modification of starch (Haralampu, 2000; Zhou & Lim,  This article is not under consideration for publication elsewhere, its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published else- where including electronically in the same form, in English or in any other language, without the written consent of the copyright-holder. ∗ Corresponding author. Tel.: +48 71 320 77 65; fax: +48 71 320 77 67. E-mail address: malgorzata.kapelko@wnoz.up.wroc.pl (M. Kapelko). 2012). Retrogradation is a process defined as the linking of starch chains into ordered structures being crystalline in character. Prop- erties of the resultant retrograded starch are determined by, among other things, the origin and type of starch, conditions of retrogra- dation and presence of other compounds (Funami et al., 2008; Korus, Witczak, Juszczak, & Ziobro, 2008; Silverio, Fredriksson, Andersson, Eliasson, & Aman, 2000; Zhou, Wang, Zhang, Du, & Zhou, 2008). The chemical modification of starch also leads to the production of resistant starch which is referred to as RS4 frac- tion. Acetylation, hydroxypropylation, phosphorylation, roasting with glycine, cross-linking with epichlorohydrin or saturation with iron ions are chemical modifications that increase starch resistance to amylolysis (Juansang, Puttanlek, Rungsardtsardt, Puncha-arnon, & Uttapap, 2012; Leszczy ´ nski, 2004). Acetylation of retrograded starch has bee shown to enable obtaining preparations of resis- tant starch RS3/4 with high resistance to the activity of amylolytic enzymes (Kapelko, Zi˛ eba, & Michalski, 2012a; Zi˛ eba, Szumny, & Kapelko, 2011b) and characterized by the capability to form vis- cous pastes (Kapelko, Zi˛ eba, & Michalski, 2012a; Zi˛ eba, Juszczak, & Gryszkin, 2011). The process of starch acetylation is deter- mined by a number of factors. Both the degree and site of substitution with acetyl groups depend on, among other things, the origin (Mirmoghtadaie, Kadivar, & Shahedi, 2009) and form of starch (Kapelko, Zi˛ eba, Golachowski, & Gryszkin, 2012), size of starch granules (Mirmoghtadaie et al., 2009), degree of crys- tallinity (Golachowski, 2003), amylose content (Mirmoghtadaie et al., 2009), and conditions of the acetylation process (González & Pérez, 2002). 0144-8617/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2013.01.002