Pasting properties of calcium-fortified rice

Calcium–fortified rice is normal rice fortified with calcium and processed by consecutive steps, i.e. infusion or soaking of the rice grain in a calcium salt solution, draining and drying. Heating during infusion causes pregelatinization of rice starch resulting in a change in the pasting properties of Ca-fortified rice. Pasting properties determine the cooking quality of rice. The purpose of the research was to evaluate the changes of the pasting properties in three varieties of calcium-fortified rice. These are: low amylose (LA), medium - (MA), high - (HA) rice and they were represented by the varieties: Memberamo, Ciherang and IR-42. The calcium salt used as a fortificant was Ca-lactate. Calcium fortification process was conducted at temperatures of 80oC and 90oC with infusion times of 10 minutes and 25 minutes. The pasting properties were determined by Brabender Amilograph (Visco amilograph) with the parameters being peak viscosity, breakdown viscosity, and gelatinization temperature. The research showed that calcium fortification of rice resulted in a calcium-fortified rice that had a higher gelatinization temperature than that of normal rice, low pasta viscosity and a flat curve of starch granules breakdown. These data explained that calcium-fortified rice took a long time to cook and resulted in a cooked-rice with a hard texture due to its decreased water binding capacity. Based on the rice amylose content, the higher the rice amylose the higher the gelatinization temperature, and the lower the paste viscosity. From these data it was found that there was a decrease in the cooking quality of calcium – fortified rice.