Journal of Agriculture Food and Development, 2016, 2, 1-4 1 © 2016 Revotech Press Production of Resistant Starch Type III from Native Sago Starch as a Potential Prebiotic Abdul M. Ahmad, Siti A. Zaman and Shahrul R. Sarbini * Department of Crop Science, Faculty of Agricultural and Food Sciences, University Putra Malaysia Bintulu Campus, Jalan Nyabau, 97008 Bintulu, Sarawak, Malaysia Abstract: Resistant starch (RS) is the sum of starch that escape upper gastrointestinal digestion and can be fermented by colonic microorganisms to produce beneficial metabolites such as short chain fatty acids (SCFA). Resistant starch can be a potential prebiotic, a non-digestible food ingredient that selectively stimulate the growth and/or activity of gut microorganisms, thus promoting the host health. The main focus of this study is to produce resistant starch type III from native sago starch. The resistant starch was produced via retrogradation process and with the aid of pullulanase enzyme. The quantification of total resistant starch content was determined based on the method approved by AOAC 2002.02 and AACC 38-40.01. From this study, it showed that there are no significant different between the resistant starch content of native and modified sago starches (RS type III). Keywords: Resistant starch, Prebiotic, Retrogradation, Sago starch. 1. INTRODUCTION Malaysia is one of the largest sago starch producers in the world with annual production of 102,600 tonnes [1]. The most important sago starch-producing crop in Malaysia is Metroxylon sagu. The starch content derived from the trunk of the sago palm is very high compare to other typical starch sources. Each palm can yield 216 to 219 kg of starch, 3 to 4 times higher than rice or corn and 17 times higher than cassava. Amylose content of sago is in the range of 21.7 to 31% while its amylo- pectin content is in the range of 69 to 78.3%. To date, sago is still considered an underutilized crop with limit- ed research carried out on the properties and function- ality of the starch [2]. When starch is consume, only their small percentage are able to escape digestion into the bowel. This portion of starch that are able to resist the upper gastrointestinal starch is termed as resistant starch [3]. It is transported to the lower gut for microbial anaerobic fermentation and may act as prebiotic. Resistant starch can be classified into five types. Type I are referred as physically inaccessible starches, such as partially milled grains and seeds. Type II are native starches with highly packed starch granules structure, such as uncooked potato starch. Type III are physically modified starches while type IV are chemically modified starches and are industrially produced through cross- linking and/or substitution. Type V are newly proposed RS, consisting of amylose-lipid complexes. Their resis- tance is the result of interaction between amylose and amylopectin with fatty acids and fatty alcohols [4]. * Address correspondence to this author at the Department of Crop Science, Faculty of Agricultural and Food Sciences, Universiti Putra Malaysia Bintulu Campus, Jalan Nyabau, 97008 Bintulu, Sarawak, Malaysia; Tel: +60 86855219; Fax: +60 86855415; E-mail: s.r.sarbini@gmail.com Resistant starches are substrates for microbial fermentation that produces metabolites which includes short chain fatty acids (SCFAs), such as acetate, lactate and butyrate which benefits the host [5]. The SCFAs are believed to have an important roles in gastrointestinal health. Moreover, RS has the ability to regulate gut microbiota favouring RS degradation pro- cess and SCFA production thus it can be considered as a prebiotic candidate [6]. In this study, retrograded sago starch (RS III) are produced through a cycle of heating and cooling process, with debranching enzyme pullulanase. 2. METHODOLOGY 2.1. Preparation of Retrograded Starch An amount of 10 g sago starch was dispersed in 40 ml of water, and then pressure-cooked in an autoclave at 121°C for 20 minutes. The autoclaved starch paste was allowed to cool to room temperature and then stored at 4°C for 24 h. The prepared starch paste was re-exposed to the cooking-cooling cycle twice and oven dried at 50°C for 24 h. The resulting retrograded sago starch (RSS) was then milled and sieved through 0.3 mm sieve. RS content in all prepared samples was analysed. Each preparation was carried out in triplicate. Fibersym ® , provided by MGP Ingredients, Inc. (Atchison, Kansas, US), was used for comparative study. Fiber- sym ® is RS type 4 and was produced by modification of wheat starch via cross-linking and substitution agent of sodium trimetaphosphate and sodium tripolyphosphate. It is a food grade cook-up resistant starch.