Classification of Rice Cultivars by Using Physicochemical, Thermal, Hydration Properties, and Cooking Quality
The classification of eight different rice cultivar was conducted to classify high amylose content rice (HM 105, RD15 and PTT1), medium amylose content rice (KTH17) and low amylose content rice (PL2, RD31, SP1 and CN1). Physicochemical, thermal, hydration, cooking quality and effect of storage time were studied in order to classify rice cultivar by principal component analysis. The results showed that amylose content of high amylose rice increased during storage time but amylose content of low and medium amylose rice were consistent. Hardness value increased during storage time. High amylose rice showed higher hardness compared to medium and low amylose. The highest and lowest hardness value was found in SP1 (901 N) and PTT1 (431 N), respectively. This indicated that amylose content affected hardness. The result of thermal properties showed that the gelatinization temperature positively correlated with amylose content. The highest onset, peak and conclusion temperature showed in RD31 (72.67�C, 77.08 �C and 84.03 �C, respectively). The storage time had no effect on thermal properties. The results showed that optimum cooking time positively correlated with amylose content. The highest optimum cooking time showed in CN1 (33.0 min) and lowest cooking time showed in HM105 (12.33 min). Hydration properties of different rice cultivar showed that high amylose content rice have capacity to absorb water more than low and medium amylose rice. The classification of rice cultivars resected in two groups by using principal component analysis. PC1 and PC2 contributed for 53.4% and 21.8% variance, respectively. The low and medium amylose were classified in one group and separate from high amylose content rice. The results suggested that amylose content alone cannot be used to classify rice cultivars. The physicochemical, thermal, hydration, and cooking quality can difference classify rice cultivar with amylose content. This results can be a useful alternative for the food industry, especially for rice noodle industry.
Keywords- Rice Flour, Cooking Quality, Amylose Content, Principal Component Analysis