초당옥수수는 고당도 옥수수 품종으로, 식단 트렌드 변화와 천연 당류에 대한 관심 증가로 인해 수요가 증가하면서 재배가 확대되고 있다. 초당옥수수는 높은 당도로 매우 달고 맛이 좋지만, 전분 함량이 낮아 일반 옥수수에 비해 발아율이 낮은 특징이 있다. 본 연구는 초당옥수수 계통의 전분 함량과 발아율의 상관관계를 조사하여, 우수한 생장과 발아율을 갖춘 고품질 계통을 선발하는 것을 목표로 하였다. 본 연구에서는 10개의 초당옥수수 계통을 대상으로 발아율과 식물체 생장 특성을 평가하였다. 모든 계통이 80% 이상의 발아율을 보였으며, KH51 계통이 53일로 가장 출사일이 빨랐고, KH29W 계통이 148cm로 간장이 가장 크게 나타났다. 고당도 계통을 선발하기 위해 수정 후 20일째에 이삭을 수확하여 유리당 함량을 측정하였다. KH28W 계통이 가장 높은 당 함량(23.3%)을 보였으며, KH45 계통이 가장 낮은 당 함량(8.1%)을 나타냈다. 또한, 전분 함량이 유리당과 비례하여 축적되는지를 확인하기 위해 수분 후 40일째에 이삭을 수확하여 분석한 결과, KH47 계통이 가장 높은 전분 함량(30.1%)을, KH28W 계통이 가장 낮은 전분 함량(23.6%)을 보였다. 전분 함량이 발아에 미치는 영향을 평가하기 위해 발아와 관련된 효소 및 유전자들을 분석하여, 발아 과정에서의 효소 활성 및 유전자 발현 수준을 측정하였다. 낮은 전분 함량은 발아 초기에 효소 활성과 유전자 발현을 저하시켜 발아 지연 및 불균일성을 초래하였으나, 발아 후 생장에는 큰 영향을 미치지 않았다. 이는 초당옥수수 종자의 초기 발아 과정이 유리당과 전분 함량에 의해 영향을 받을 수 있음을 시사한다.

Rice ratooning is the cultural practice that easily produces secondary rice from the stubble left behind after harvesting the main crop. ‘Daol’ is an extremely early growing rice variety. Planting this variety early allows for an additional ratoon harvest after the primary rice harvest. The plant growth and yield of ratoon rice were very low compared to those of main rice. Protein, amylose content, and head rice rate were higher in ratoon rice than in main rice. The distribution by the rice flour particle size of main and ratoon rice was similar. The damaged starch content in ratoon rice was relatively high at 6.1%. Ratoon rice required a longer time and higher temperature for pasting than main rice. Compared to the original rice, peak viscosity (PV), hot paste viscosity (HPV), cool paste viscosity (CPV), and breakdown (BD) were very low, and setback (SB) was high. As a result of analyzing the gelatinization properties of main and ratoon rice using differential calorimetry, it was found that the onset (To), peak (Tp), and conclusion (Tc) of ratoon rice starch were processed at a lower temperature than those of main rice. The gelatinization enthalpy of both samples was similar. The distribution of amylopectin short chains in ratoon rice was higher than that in main rice.

This study established optimal cookie conditions by varying the amount of modified starch treated with octenyl succinic anhydride (OSA). It also investigated the quality and digestion characteristics of the cookies produced. The moisture content increased as the amount of OSA-modified starch added to the cookies increased. As for cookie color brightness, the redness and yellowness decreased as the OSA-modified starch content increased. The spread factor and hardness of the cookies showed the most similar results for control and OSA: 20%. As the amount of OSA-modified starch added to cookies increased, RS tended to increase. It was found that OSA-modified starch cannot easily replace wheat flour completely and that the optimal amount of OSA-modified starch added to cookies is 20%. OSA-modified starch can be used not only as a cookie but also as a low-calorie food ingredient.

This study established the optimal conditions of noodles by varying the amount of modified starch treated with octenyl succinic anhydride in wheat starch. It investigated the digestibility and quality characteristics of the produced noodles. The color difference of the noodles added with octenyl-succinic anhydride (OSA)-modified starch increased as the amount of OSA-modified starch added increased but decreased after cooking. The cooking characteristics of noodles added with OSA-modified starch showed increased weight, water absorption, and turbidity but reduced volume. In the extensibility of noodles, the noodles with 10 and 20% OSA-modified starch showed the most similar values to the control. The digestibility of noodles with OSA-modified starch added showed a higher RS content as the amount of OSA-modified starch added increased. However, it is considered that an optimal addition level of 20% of modified starch is suitable for the formation of noodle texture. As a result of this study, it is thought that OSA-modified starch, with its low digestibility, could be utilized not only in noodles but also as a low-calorie food ingredient that can replace wheat flour.