Effect of moisture content of two paddy varieties on the physical and cooked properties of produced rice

Abstract Yasemin and Anber are the main rice varieties cultivated in Iraq. Anber is the favorite variety in Iraq because of its unique flavor, and Yasemin is the most cultivated variety. Determining the suitable moisture content of both varieties to produce high extraction rate (lowest rice breakage), good rice whiteness, and the best rice quality in terms of cooked properties was the purpose of this study. Moisture content (MC) (10%, 12%, 14%, 16%) of Yasemin and Anber were used, and targeted whiteness (32, 34, and 36) were obtained by using different milling times. Results showed that the best moisture content was 14% for Yasemin variety and 10% for Anber variety in terms of extraction rate. Process time increasing led to reduction of extraction rate and increased rice whiteness. The highest extraction rate of Yasemin and Anber was 56% and 64% with 32 whiteness, respectively. Kernel breakage had opposite relationship with extraction rate. Yasemin and Anber varieties were classified as short grain rice depending on their length. The maximum elongation was at 16% MC for Yasemin variety and at 10% MC for Anber variety, which increased 60% more than uncooked rice. There was no definite pattern observed for increasing rice volume (width and weight). In conclusion, the extraction rate of Yasemin and Anber varieties was increased at 14% and 10% MC, respectively. For cooked properties, 10% MC of Anber was the best in terms of rice elongation, while 16% MC was the best for Yasemin variety.

Gastric emptying rate and chyme characteristics for cooked brown and white rice meals in vivo

BACKGROUND

Rice structure is important to rice grain and starch breakdown during digestion. The objective of this study was to determine the gastric emptying and rice composition during gastric digestion of cooked brown and white medium-grain (Calrose variety) rice using the growing pig as a model for the adult human.

RESULTS

Brown and white rice did not show significantly different gastric emptying rates of dry matter or starch, but brown rice had slower protein emptying (P < 0.05). Moisture content was greater and pH was lower in the distal stomach compared to the proximal stomach (P < 0.0001), and varied with time (P < 0.0001). The mechanism of physical breakdown for brown and white rice varied. Brown rice exhibited an accumulation of bran layer fragments in the distal stomach, quantified by lower starch and higher protein content.

CONCLUSION

The quantity of gastric secretions observed after a brown or white rice meal may be related to the meal buffering capacity, and are accumulated in the distal stomach. The delayed rate of protein emptying in brown rice compared to white rice was most likely due to the accumulation of bran layers in the stomach.