Kuzu (Pueraria lobata) starch, an important ingredient of Japanese confectionery, is said to show superior cooking properties by storage at room temperature to new one. And heat/moisture-treatment (HMT) is well known to give starch granules different properties. In this study, the cooking properties of HMT Kuzu starch at 120°C for from 10 min to 120 min were investigated.
The longer starch was treated, the more color of starch changed to yellowish. X-ray diffraction patterns were changed from type CA to type A. In addition, the particle size distribution percentage of HMT Kuzu starch increased in larger one depending on the treated time. Although the hardness and adhesiveness of HMT Kuzu starch-sol were not so different just after preparation from those of untreated one, their hardness and adhesiveness increased rapidly under storage at 35°C depending on HMT time. Rapid Visco Analyzer (RVA) showed that HMT significantly (p<0.005) increased their gelatinization temperature and lower peak viscosity depending on HMT time.
