Tocopherol and tocotrienol contents of different varieties of rice in Malaysia.
BACKGROUND
The present study examined the contents of tocopherols and tocotrienols and their distribution in 58 different varieties of whole rice cultivated in Malaysia. The analytical method used was saponification of samples followed by dispersive liquid-liquid microextraction and reverse phase high-performance liquid chromatography.


RESULTS
The total vitamin E contents of different varieties of whole rice ranged between 19.36 and 63.29 mg kg⁻¹. Contents of vitamin E isomers varied among rice varieties both within and between grain color groups. Black-pigmented rice showed significantly higher mean contents of α-tocopherol, β-tocopherol and α-tocotrienol than non-pigmented rice and red-pigmented rice. Red-pigmented rice had significantly lower mean contents of γ-tocotrienol and total vitamin E than non-pigmented rice. The mean contents of δ-tocotrienol and total vitamin E in non-pigmented rice, however, were similar to those in black-pigmented rice. γ-Tocotrienol was the predominant form of vitamin E isomer in all analyzed varieties. The Pearson correlations among vitamin E isomers and total vitamin E content of whole rice were also studied.


CONCLUSIONS
This study provides information on vitamin E content of different rice varieties that would be beneficial for decision making in genetic breeding of bioactive compound-rich rice varieties.
UPM-BERNAS Research Laboratory, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia.
Balakrishnan
B
Shammugasamy
Yogeshini
Y
Ramakrishnan
Hasanah M
HM
Ghazali
Kharidah
K
Muhammad
D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D018556:Crops, Agricultural / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D005511:Food Handling; D006801:Humans; D006868:Hydrolysis; D059625:Liquid-Liquid Extraction; D008296:Malaysia; D009753:Nutritive Value; D012275:Oryza / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D010860:Pigments, Biological / Q000096:biosynthesis; D015203:Reproducibility of Results; D012639:Seeds / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism; D013045:Species Specificity; D024505:Tocopherols / Q000032:analysis* / Q000378:metabolism; D024508:Tocotrienols / Q000032:analysis* / Q000378:metabolism; D024502:alpha-Tocopherol / Q000032:analysis / Q000378:metabolism; D024503:beta-Tocopherol / Q000032:analysis / Q000378:metabolism
D010860:Pigments, Biological; D024508:Tocotrienols; D024503:beta-Tocopherol; C082032:tocotrienol, alpha; D024502:alpha-Tocopherol; D024505:Tocopherols
Malaysia: microextraction; rice varieties; tocopherol; tocotrienol