Effects of Leached Amylose and Amylopectin in Rice Cooking Liquidon Texture and Structure of Cooked Rice

ABSTRACT Effects of leached amylose (AM) and amylopectin (AP) on textural and morphological properties of cooked rice were investigated separately by replacing cooking liquid with AM and AP separated from pouring cooking liquid. The pouring of cooking water reduced the hardness (from 28.45 to 19.42N) and stickiness (from 1.74 to 1.19N·s) significantly. However, the addition of AM and AP enhanced the hardness (27.63N) and stickiness (1.71N·s).Scanning electron microscopy show that the leached short-chain AM entered the surface hollows in the cooked rice after water evaporation. Meanwhile, the Long-chain AM cross-linked to formed a three-dimensional network structures, which covered on the filled hollows. This distribution led to a harder texture of cooked rice. The leached AP absorbed water and swelledto form masses. Atthe gelatinization temperature,theAPmassesagglomeratedtoformafilmlayer,whichcoveredtheunevenstructure, the thicker and smoother film contributed to the sticky texture.

Morphological and mechanical properties of the Achilles tendon in adolescent boys / 体力科学

The present study aimed to investigate how the morphological and mechanical properties of Achilles tendon change in adolescent boys. Twenty-nine adolescent boys and 12 male adults participated. Ultrasonography was used to measure Achilles tendon elongation. The transition point, that is, the intersection point of the “Toe” and “Linear” regions was determined from tendon elongation-tendon force relationship, and the stiffness and Young’s modulus of the Achilles tendon were calculated from linear region. The hysteresis was calculated as the ratio of the area within the tendon elongation-tendon force loop to the area beneath the load portion of the curve. The stiffness, Young’s modulus and stress at transition point were greater in adults (544 ± 231 N/mm, 1.6 ± 0.7 GPa, 23 ± 6 MPa) than in adolescents (374 ± 177 N/mm, 1.1 ± 0.7 GPa, 19 ± 10 MPa). However, no differences were observed in the tendon length and the tendon cross-sectional area and stress at transition point between adolescents (174 ± 23 mm, 60 ± 11 mm², 6.1 ± 2.0 %) and adults (180 ± 30 mm, 63 ± 7 mm², 5.5 ± 2.2 %). The hysteresis in adolescents (20 ± 18 %) was greater than that of adults (12 ± 10 %). These results suggest that the morphological properties of Achilles tendon are similar between adolescents and adults, but that mechanical properties are altered with growth to become a stiffer and more spring-like structure.

Mechanical and Morphological Properties of the Growing Long Bone: A Torsion Study on Rabbit's Femur / 대한정형외과학회잡지

It is essential to define the mechanical and morphological characteristics of bone in undrestanding the mechanism and treatment of fractrues of bone. We already reported the results of bending study in 1983 and tension study in 1987 to assess the mechanical and morphological changes of bone according to the growth. Following these studies, we performed torsion study on growing long bone to have better understanding of the characteristics of bone. In order to assess the mechanical and morphological properties of fracture of growing bone by torsion, we divided 100 Newzealand white rabbits(40 1-month-old rabbits, 20 3-months old rabbits and 40 5-months-old rabbits) into 6 experimental groups according to their maturity and side : Group 1(right femur of 1 month old), Group 2( left femur of 1 month old), Group 3(right femur of 3 months old), Group 4(left femur of 3 months old), Group 5(right femur of 5 months old), Group 6(left femur of 5 months old). Each group of femora were loaded in torsion with varing distance and the following results were obtained: 1. Fracture shapes were composed of the spiral component and the vertical component which connected the two ends of the spiral component. 2. Younger bones revealed greater deformation angle and apex angle but less obliquity than older bones. 3. When the gap between the grips were lengthened three times, there was a very signi ficant increase of deformation angle and obliquity but apex angle was decreased and the fracture angle showed little change. 4. It was necessary to measure the apex angle and obliquity in the morphological description of fractures by torsion. 5. We observed when a certain degree of angular deformity was applied on a bone at a certain age, the fracture was occured through the tension failure regardless of types of loading forces.