The evaluation of a dryer performance in terms of energy consumption, drying capacity and
quality of final product is the main concern of rice milling industry at any time. A study was
implemented to investigate on the benefits of common drying practices by studying the drying
performances of flat-bed and inclined-bed dryers which are popular in rice industry in Malaysia
and neighbouring countries. For this purpose, flat-bed dryer (FBD) and inclined-bed dryer
(IBD) were designed, fabricated and operated in the laboratory based on actual industrial
drying conditions. The results revealed that inclined-bed drying significantly increased drying
capacity (ton m-2 h-1) of up to 25 % at drying temperature of 42-43°C and almost 29 % at 38-
39°C drying air temperature compared to flat-bed drying. Furthermore, overall drying energy
consumption in IBD was found to vary between 78.6 to 91.97 kW.h ton-1, while for FBD the
energy consumption was more than 200 kW.h ton-1 for both levels of drying air temperatures.
Both dryers were found to produce rice with desired/ acceptable commercial quality index,
even though the head rice yields of FBD were higher than that of IBDs.
This experimental study was carried out to investigate the effect of eight types of commercial rice in Malaysia on blood glucose response and to determine their glycaemic index (GI) values. Ten healthy Malay volunteers (7 males, 3 females, BMI=23.6kgm-2, age=25.1years) participated in this study. The eight types of rice tested were three high fibre rice (HFR A, HFR B & HFR C), three white rice (WR D, WR E and WR F) and two fragrant rice (FR G and FR H). The subjects were required to go through the study protocol on eleven separate occasions (eight tests for the test rice samples and three repeated tests for the reference food) after an overnight fasting. Capillary blood samples were taken immediately before (0min) and 15, 30, 45, 60, 90 and 120min after consumption of the test foods. The blood glucose response was obtained by calculating the incremental area under the curve (iAUC). The GI was determined according to the standardised methodology. This study showed that out of eight types of rice tested, three (HFR B, WR E and WR F) could be categorised as having intermediate GI while the remaining five were considered high GI foods (HFR A, HFR C, WR D, FR G and FR H). The GI of HFR B (60 ± 5.8) and WR E (61 ± 5.8) were significantly lower than the reference food (glucose; GI=100) (p0.05). The GI value of the rice tested in descending order were HFR C, 87 ± 9.0 followed by HFR A (81 ± 6.7), FR G (80 ± 5.5), FR H (79 ± 7.6), WR D (72 ± 8.5), WR F (69 ± 8.3), WR E (61 ± 5.8) and HFR B (60 ± 5.8). There was no relationship between the dietary fibre content of the rice with the iAUC (r= -0.05, p=0.63) and GI values (r= -0.08, p=0.46). This shows that the GI values of the test rice were independent of the dietary fibre content of the rice. Other factors that may influence the GI value of rice include amylose content, gelatinisation process and botanical sources. The results of this study will provide useful information for dietitians and nutritionists in selecting the appropriate type of rice for the daily diet of diabetics.