สมบัติเชิงกลของเมล็ดข้าวเหนียวนึ่งสุก

Abstract

The purpose of this thesis is to determine the mechanical properties, modulus of elasticity and Poisson’s ratio, of steamed-cooked Thai Sanphathong 1 glutinous rice (GR). In the cooking process, there are two types of soak methods, normal soaking and pressure soaking. The soaking process can affect the properties of cooked rice. To compare the characteristic of the stickiness of those two methods cooked GR kernels soaked, ASAE 368.4 (American Society of Agricultural and Biological Engineers for Compression Test of Food Materials of Convex Shape) was employed as main protocol for property testing and then Hooke’s and Hertz’s equations were used to estimate the modulus of elasticity. Poisson’s equation was used to estimate the Poisson’s ratios. The results show that the modulus of elasticity determined by using Hooke’s theory of the cooked normal-soaked and pressure-soaked rice were 3.77 MPa and 5.67 MPa , respectively. The modulus of elasticity determined by using Hertz’s theory of the cooked normal-soaked and pressure-soaked rice were 1.58 MPa and 2.33 MPa, respectively. Poisson’s ratio of the cooked normal-soaked and pressure-soaked rice were 0.27 and 0.28, respectively.