Quantitative Evaluation of Kuchidoke from Rice Crackers

Abstract

Kuchidoke, or “the melt-in-your-mouth feeling”, is an important characteristic of rice cracker texture. In this study, we established a novel method for quantitatively evaluating the kuchidoke of rice crackers from their internal microstructure and physical properties. Maximum load, water absorption time, the half-life of rice-cracker viscosity reduction caused by enzymatic degradation, and particle size at the end of degradation were analyzed. We evaluated the possible correlation of kuchidoke values of glutinous or non-glutinous rice crackers as determined by “Quantitative Descriptive Analysis” with the corresponding values determined from internal microstructure and physical property values. It was found that rice crackers with lower maximum load in the compression test and larger pore size had higher kuchidoke values. We used structure and physical property parameters selected by a stepwise multiple regression procedure to develop the following equation. y＝0.2290566x₁＋0.4849081x₂＋41.337392x₃－2.433181x₄＋46.285197x₅＋0.1078257x₆－182.242600 (R²＝0.9780, p<0.01) Using this multiple regression equation, we showed that rice cracker kuchidoke can be accurately estimated by measuring pore structure thickness (x₁), pore size (x₂), number of pores (x₃), maximum load (x₄), half-life of viscosity reduction (x₅), and residual particle size (x₆).