INFLUENCE OF GLASS TRANSITION TEMPERATURE ON RATE OF RICE STARCH RETROGRADATION DURING LOW-TEMPERATURE STORAGE

2005 ◽  
Vol 28 (5) ◽  
pp. 506-525 ◽  
Author(s):  
CHUAN-LIANG HSU ◽  
DENNIS R. HELDMAN
2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Zhe Yang ◽  
Xue Han ◽  
Huiying Wu ◽  
Lijuan Zhang ◽  
Lanwei Zhang ◽  
...  

Rice and its products are widely consumed in Asian countries; however, starch retrogradation decreases the quality and shortens the shelf-life of rice foods particularly at low temperature. In this study sucrose ester (SE), glycerol monostearate (GMS), and sodium stearoyl lactylate (SSL) were added to rice flour and corresponding rice gels. Then, gelatinization properties, retrogradation characteristics, texture, and water content of these rice gels were investigated at 4°C and −20°C storage, respectively. The results demonstrated that the rice gels with 0.2% GMS had the lowest retrogradation index (ΔHr/ΔHg) (11.84%) and hardness (1359 g) at 4°C for a 10 d period, which was significantly lower in comparison to control and the other two emulsifiers (P<0.05). Adhesiveness and water content were increased compared to the other samples. Furthermore, the retrogradation of rice gels stored at 4°C was comparatively rapid compared to gels stored at −20°C. Gel samples stored at −20°C were still acceptable for more than 15 days. Thus it was revealed that GMS has the potential to retard starch retrogradation and produce high-quality rice products in preservation.


2016 ◽  
Vol 48 (8) ◽  
pp. 691-710
Author(s):  
Yong-Chan Chung ◽  
Hyeryoung Yoon ◽  
Jae Won Choi ◽  
Byoung Chul Chun

Citric acid (CA) was used as a grafted group onto polyurethane (PU) to form a CA-grafted PU series, with a control PU series containing free CA prepared for comparison. With an increase in the CA content, the enthalpy change during the melting increased for the PU and CPU series, and the glass transition temperature increased with the increase in CA content for the PU series but not for the CPU series. The tensile strengths of the PU series sharply increased with the CA content, whereas those of the CPU series did not. The PU series demonstrated better low-temperature flexibility and water permeability than the unmodified PU.


2000 ◽  
Vol 6 (S2) ◽  
pp. 316-317
Author(s):  
O. L. Shaffer ◽  
M. S. El-Aasser

Latexes are dispersions of homopolymers and copolymers, usually in water. Uses of these latexes are many such as protective coatings and adhesives. In order to form a continuous film the polymer must have film forming properties such as a low glass transition temperature (Tg). Latexes are being designed such as one polymer in the core of the particle and a shell of another polymer or perhaps a series of shell layers. Microscopy has become a powerful tool in the examination of the morphology of the latex particles. Because of the use of low Tg polymers, sample preparation and examination by electron microscopy at temperatures above the Tg of the polymer causes the particles to become distorted and no longer representative of their true morphology. Low temperature methods therefore have become crucial in the field of latex microscopy.


Sign in / Sign up

Export Citation Format

Share Document