Flat rice noodle is classified under non-wheat noodles due to the absence of gluten and
required gelatinization of starch during processing. It is also very susceptible to spoilage
and has a short shelf-life because of the high moisture content. This study was conducted
to investigate and compare the effect of gamma irradiation on the physicochemical
characteristics and microbiological quality of containing two different starches. Tapioca
starch (TS) and potato starch (PS) were incorporated into the formulations at 3 levels (3%,
8% and 11%) and was irradiated at 4 doses of 0 (control), 4, 6, and 8 kGy with dose rate
of 42.78 Gy/min by using 60Cobalt. Total plate count (TPC) was performed where samples
were stored at 8°C and examined for day 1, 3, 5, and 7. Results showed that all doses of
irradiation did not significantly (p>0.05) affected the moisture content and water activity
of samples. However, gamma irradiation significantly (p<0.05) decreased the pH value,
cooking yield, lightness, and hardness of the samples; whereas it significantly (p<0.05)
increased the cooking loss, colour (a* and b*), and breaking length. Meanwhile, cooking
yield, lightness, and hardness of samples containing PS were higher compared to samples
containing TS. Moisture content for samples containing both TS and PS was higher
compared to samples containing single starch. TPC showed that irradiation was able to
control microbial growth. Moreover, no microbial load was detected on samples irradiated
at 8 kGy until day 7. It was thus shown that increased doses in gamma irradiation could
improve microbiological quality of flat rice noodles
Effect of Processing Treatment on Physicochemical Characteristics of Brown Rice Varieties with Different Amylose Content