Principal component analysis (PCA) of
the pasting properties of HMRF, RD6, Niew Ubon
and mixed flour samples showed that the two
principal components (PCs) explained total
variance of 93% (Figure 2). PC1 (83% variance)
was characterized positively by trough. PC2 (10%
variance) was characterized positively by peak,
breakdown, final viscosity, setback and pasting
temperature, whereas peak time was characterized
negatively in PC2. The result from PCA and cluster
analysis classified the samples into 3 groups.
Cluster 1, composed the glutinous rice flour
samples (RD6 and Niew Ubon), was grouped
based on high breakdown, low final viscosity and
setback. Cluster 2, composed of mixed flour
samples (HMRF:RD6 and HMRF:Niew Ubon in
ratios of 1:1 and 1:3), was characterized as having
medium breakdown, setback and final viscosity.
Cluster 3, composed of mixed flour samples
(HMRF:RD6 and HMRF:Niew Ubon in a ratio of
3:1) and HMRF was grouped based on low
breakdown, high final viscosity and setback.
Additionally, mixed flour could be classified into
three groups according to amylose content: 1) low
amylose (< 4%) that is, glutinous rice flour, 2)
medium amylose (6–10%) that is, mixed flour
(HMRF:RD6 and HMRF:Niew Ubon in ratios of
1:1 and 1:3) and 3) high amylose (> 12%) that is,
mixed flour (HMRF:RD6 and HMRF:Niew Ubon
in a ratio of 3:1) and HMRF