Relationship between rice grain quality traits and starch pasting properties using early maturing rice cultivars in Chungnam plain area

Abstract

: This study was conducted to know the variation and relationship of rice grain quality and starch pasting properties by transplanting times. Two early maturing rice cultivars which accounted for the most area of early maturing rice cultivar in Chungnam province were used. The experiment was laid out in a split-plot design with 3 replications. The main plot consisted of three transplanting times viz. early (April 25), ordinary (May 25) and late (June 25) with sub-plots containing two cultivars. According to the transplanting times, most of rice grain quality and starch pasting properties showed significant difference and Joami showed higher grain quality than Unkwang in all transplanting times. Especially, rice grain quality was improved when transplanted late, showing high head rice and glossiness of cooked rice due to the lower mean temperature during grain filling stage. Glossiness of cooked rice was positively correlated with head rice ratio, amylose content and setback value, and negatively correlated with chalky rice ratio and protein content. The highest positive and negative correlation were observed between breakdown value and peak viscosity (r = 0.98**), and breakdown and setback (r = -0.94**), respectively. These results provide some information for rice researchers and producers producing cultivars with an improved quality, suggesting that rice quality is highly influenced by temperature at grain filling stage, and transplanting times is crucial in improving rice quality. In addition, starch pasting properties are useful for determining rice quality because rice grain quality and starch pasting properties are dependent on each other.

Model‐based evaluation of climate change impacts on rice grain quality in the main European rice district

“…Correlation analysis showed significant relationships between variables connected to milling and cooking suitability, and our results were consistent with previous studies, with few exceptions. In agreement with literature, amylose content was positively correlated with setback (Pang et al, 2016), gelatinization temperature (Varavinit et al, 2003), and head rice yield (Yun et al, 2015) and negatively with breakdown and peak viscosity (Pang et al, 2016). Consistent relationships emerged also for the indices related to starch viscosity properties, except for the relationship between gelatinization temperature and setback, which is contrasting in available studies (significant positive, Yun et al, 2015;non-significant negative, Pang et al, 2016).…”

“…In agreement with literature, amylose content was positively correlated with setback (Pang et al, 2016), gelatinization temperature (Varavinit et al, 2003), and head rice yield (Yun et al, 2015) and negatively with breakdown and peak viscosity (Pang et al, 2016). Consistent relationships emerged also for the indices related to starch viscosity properties, except for the relationship between gelatinization temperature and setback, which is contrasting in available studies (significant positive, Yun et al, 2015;non-significant negative, Pang et al, 2016). In our study, breakdown was positively associated with peak viscosity and negatively to setback and gelatinization temperature; peak viscosity was negatively correlated with setback and gelatinization temperature, and gelatinization temperature positively related to setback.…”

Amylose content and RVA profile characteristics of noodle rice under different conditions

“…A quadratic curve relationship exists between the amylose content and the temperature during the grain‐filling stage in most varieties and the temperature during the early grain‐filling period has the largest impact (Ahmed et al., ; Zhou, Zhang, Gao, & Zhu, ). Likewise, the amylose content of Indica cultivars was parabolically correlated to the temperature for 20 d after full heading under artificial temperature control (Patindol, Siebenmorgen, & Wang, ), although the amylose content was found to be negatively correlated with sunshine hours during the grain‐filling period (Yun et al., ).…”