Improvement of Cooking Properties by Milling and Blending in Rice Cultivar Goami2

The functional vice (Oryza sativa L.) has been highly regarded recently, in the change of rice maykets in the world. Goami2 (GA), one of the functional rice varieties, was developed from high-quality rice, Ilpumbyeo (IP). From the previous study, GA has been proved its beneficial effect on the improvement of metabolic control and body weight reduction especially in obesity, We could certain that GA was very difficult to be gelatinized due to the micro lump shown in the Scanning electron micrographs (SEM) photos. To improve its cooking quality, we investigated the changes of physicochemical properties, which were differentiated by the conditions of milling and blending. As GA was milled every $2\%$ until eliminating $12\%$, the nitrogen content was decreased linearly. But the decreasing rate of nitrogen content of GA during milling process was relatively lower than that of IP. Thus, we assumed that GA has relatively high nitrogen in inner starch of grain. The degree of milling had no effect on the gelatinization of cooked GA, but affected lightness and whiteness linearly, which were ranged in normal values when the rice was milled more than $10\%$ in weight. So we could concluded that the milling process was not proper to improve cooking quality of GA. And we could suggested that GA was needed to soak into water at least one hour before cooking by it water absorption rate at normal temperature$(21^{\circ}C)$ and sensory evaluation. From the texture analysis, cooked GA had higher hardness than other varieties. Therefore, we blended GA with IP, Baekjinju(BJ) and Hwasunchalbyeo(HS), then subjected to sensory evaluation. All evaluation items including the sensory preference were the highest scores for the rice blended with glutinous rice varieties, BJ and HS.

도정 및 품종혼합에 의한 고아미2호의 취반특성

난소화성 다당류의 함량이 높은 고아미2호의 취반특성 개선 및 식미 향상을 목적으로 수행한 연구결과는 다음과 같았다. 1. 취반이 어려운 것으로 알려진 고아미2호는 가루로 1차 호화시킨 후에도 미세전분입자는 호화되지 않은 것으로 나타나 일반적인 취반방법으로는 식미개선에 어려움이 있는 것으로 나타났다. 도정에 의해서 색, 물성 및 호화특성의 변화를 살펴 보았으나 명도와 백도 이외에는 도정율에 따른 유의한 특성 변화는 없는 것으로 나타났다. 2. 상온수분흡수특성을 통해 고아미2호 최소 1시간 이상의 수침시간을 필요로 하며 관능평가를 통해 이 경우 식미가 더 양호함을 확인할 수 있었다. 3. 품종별 호화 및 취반특성을 비교해 본 결과 고아미2호의 호화개시온도가 $88^{\circ}C$로 매우 높고 일반 밥솥에서 취반할 경우 수분흡수율과 팽창용적이 적은 것으로 보아 취반 방법에 있어서 고온고압이 요구되는 것으로 나타났다. 4. 다른 품종과의 혼합을 통한 식미 혹은 물성 개선을 위해 아밀로스 함량이 다른 일품벼, 백진주, 화선찰벼를 비교한 결과 호화가 늦고 경도가 낮으며 노화특성이 양호한 백진주, 화선찰벼가 일품벼에 비해 더 적합할 것으로 예상되었고, 관능 평가를 통해 두 품종이 일품벼에 비해 전반적으로 더 양호한 것으로 나타났다.