A variety of rice cultivars have been developed and their usages are being expanded to develop value added products in relation to their physicochemical properties. Cyclodextrin (CD), commonly produced from potato starch, is widely used in food and pharmaceutical industries. So far, few studies have been reported on the CD production from rice starches. In this study, the physicochemical properties of various rice starches were investigated and their substrate performance were evaluated for the CD production using cyclodextrin-glucanotransferase (CGTase). Starches of 5 Korean rice cultivars, Dodamssal (DD), Ilpummi (IP), Saegoami (SG), Sintoheukmi (SH), and Geonganghongmi (GH) were isolated by alkaline extraction method. The amylose content of DD and SG was ~66% and ~30%, respectively, while the others ranged from ~18% to ~23%. A similar amylopectin branch chain length distribution was observed in SH, GH, and IP, showing higher content of middle chains B1. SG showed higher content of the short chains A and lower content of the long chains B3+ than SH, GH, and IP, whereas DD showed opposite trends. RVA pasting properties showed the lowest values of peak viscosity, breakdown, and final viscosity in DD. The X-ray diffraction pattern of DD was the typical B-type pattern, whereas the others showed A-type patterns. Most starches had typical polygonal granular shapes, whereas DD showed round shape as revealed by SEM. In order to produce CD, starches were treated with isoamylase, CGTase and glucoamylase in a sequential order. DD showed the highest CD yield of 83% and GH showed the lowest CD yield of 70%. Based on this study, it can be concluded that the starches with high amylose contents tend to show low peak viscosity, high pasting temperature, and high CD production yield.

• Kyeongseon Joo(Center for Food and Bioconvergence Department of Biosystems and Biomaterials Science & Engineering, Seoul National University)
• Shin-Joung Rho(Center for Food and Bioconvergence Department of Biosystems and Biomaterials Science & Engineering, Seoul National University)
• Young-Lim Kim(Center for Food and Bioconvergence Department of Biosystems and Biomaterials Science & Engineering, Seoul National University)
• Saehun Mun(Center for Food and Bioconvergence Department of Biosystems and Biomaterials Science & Engineering, Seoul National University)
• Yong-Ro Kim(Center for Food and Bioconvergence Department of Biosystems and Biomaterials Science & Engineering, Seoul National University)