| dc.description.abstract | The aim of this project was to investigate the effect of different cooking
temperatures (80, 100 °C) and different times (30, 40, 50, 60 and 70 min) on
physicochemical characteristics, texture and sensory quality of heat- moisture
treated unpolished red rice using acetic acid as cooking solution. Unpolished red
rice with 30% moisture content was heated moisture treatment (HMT) at 1200C.
Samples were analyzed for water absorption, cooking loss, degree of
gelatinization, scanning electron microscopy (SEM), texture analysis, sensory
evaluation. The results showed that HMT rice reduced water absorption, cooking
loss and degree of gelatinization. Among different time and temperature factors,
HMT rice had the best results of physical properties at 800C for 60 min and 1000C
for 40 min, which used for textural and sensory tests. Using SEM technique, the
microstructure revealed that the signs of the loss of granule integrity and smooth
surface were presented in cooked rice samples at 100oC more than untreated
samples as well as two samples cooked at 80oC. Besides, the addition of an acetic
acid (0.05M) helped cooked rice to become better gelatinization and swelling of
rice starch as well as causing decrease in pore size, possibly due to the strong
impact of acid on amylose and amylopectin. The result was the acceptance of
consumers in sensory evaluation in term of textural properties of HMT rice with
higher hardness, lower cohesiveness and springiness than untreated ones.
According to the obtained results, the most suitable cooked rice among treated
samples were the HMT800C-60min and HMT1000C-40min. | en_US |
