Chiang Mai Journal of Science

Jasmine rice was produced from varieties Khao Dowk Mali 105 (KDML 105) and Kor Kho 15 (RD15). Adulteration of Jasmine rice with other varieties such as Pathum Thani 1 (PTT 1) and Chai Nat 1 (CNT 1) is a problem encountering Thailand rice export.  Department of Agriculture of  Thailand try to establish testing method for Jasmine rice’s adulteration using dyed grain method.  Results showed that this method was not accurate when Jasmine rice was adulterated with similar amylose content rice varieties or at low adulteration level.  This study tried to investigate more rapid and accurate method to detect Jasmine rice’s adulteration. Jasmine rice, KDML 105 variety, was adulterated with CNT 1 and PTT 1 at level 5, 8, 10, 15, 20, 25 and 30 %.  Classification of these adulterations of Jasmine rice using its textural and pasting properties was achieved by applying Principal Component Analysis (PCA).  PCA could classified adulteration of  Jasmine rice efficiently.  The first two principal components explained 81.6% and 90.5% of the total variance explained for CN1 and PTT1 adulteration respectively.  Prediction model using linear regression confirmed that physico-chemical properties could be used as the more accurate parameters to predict adulteration in Jasmine rice. Its coefficient of  determination (R²) equaled to 0.981 and 0.921 for CNT 1 and PTT 1 respectively.