The sale of brown rice batches composed of rice produced in different years is prohibited in Korea. Thus, new methods for the identification of the year of production are critical for maintaining the distribution of high quality brown rice. Here, we describe the exploitation of an enzyme that can be used to discriminate between freshly harvested and one-year-old brown rice. The degree of enzyme activity was visualized through freshness test with Guaiacol, Oxydol, and p-phenylenediamine reagents. With electronic eye equipment, we selected 29 color codes for identifying new brown rice and old brown rice. The discrimination power of selected color codes showed a minimum of 0.263 to a maximum of 0.922 and an average value of 0.62. The accuracy with which new brown rice and old brown rice could be identified was 100% in principal component analysis (PCA) and discriminant function analysis (DFA). The DFA analysis had greater discriminatory power than did the PCA analysis. A verification test using new brown rice, old brown rice, or a mixture of the two was then performed to validate our method. The accuracy of identification of new and old brown rice was 100% in both cases, whereas mixed brown rice samples were correctly classified at a rate of 96.9%. Additionally, in order to test whether the discriminant constructed in winter can be applied to samples collected in summer, new and old brown rice stored for 8 months were collected and tested. Both new and old brown rice collected in summer were classified as old brown rice and showed 50% identification accuracy. We were able to attribute these observations to changes in enzyme content over time, and therefore we conclude, it will be necessary to develop discriminants that are specific to distinct storage periods in the near future.
- Bougrini, M., K. Tahri, Z. Haddi, T. Saidi, N. E. Bari, and B. Bouchikhi. 2014. Detection of adulteration in argan oil by using an electronic nose and a voltammetric electronic tongue. Journal of Sensors. 2014 : 1-10.10.1155/2014/245831
- Chen, T. F. and C. L. Chen. 2003. Analysing the freshness of intact rice grains by colour determination of peroxidase activity. Journal of the Science of Food and Agriculture. 83 : 1214-1218. 10.1002/jsfa.1528
- Choi, J. Y., K. H. Bang, K. Y. Han, and B. S. Noh. 2012. Discrimination analysis of the geographical origin of foods. Korean J. Food Sci. Technol. 44(5) : 503-525.10.9721/KJFST.2012.44.5.503
- Chrastil, J. 1990. Influence of storage on enzymes in rice grains. Journal of Agricultural and Food Chemistry. 38 : 1198-1202.10.1021/jf00095a00810.1021/jf00099a005
- Hong, J. H., J. H. Lee, Y. H. Cho, K. H. Choi, M. H. Lee, Y. J. Park, and H. T. Kim. 2017a. Discrimination analysis of new rice, stale rice, and their mixture using an electronic eye. Korean J. Food Sci. Technol. 49(5) : 469-473.
- Hong, J. H., J. S. Ahn, Y. K. Kim, K. H. Choi, M. H. Lee, Y. J. Park, H. T. Kim, and J. H. Lee. 2017b. Discrimination analysis of production year of rice and brown rice based on phospholipids. Korean J. Crop Sci. 62(2) : 105-112.10.7740/kjcs.2017.62.2.105
- Korean Statistical Information Service, 2018. KOSIS Database. http://kosis.kr. Accessed on 2 January, 2018.
- Koyachi, E., K. Kojima, X. Qiu, T. Satake, and H. Suzuki. 2013. Electrochemical microdevice for on-site determination of rice freshness. Biosensors and Bioelectronics. 42 : 640-645.10.1016/j.bios.2012.11.00623274181
- Matsukura, U., S. Kaneko, and M. Momma. 2000. Method for measuring the freshness of individual rice grains by means of a color reaction of catalase activity. J. Jpn. Soc. Food Sci. Techno. Nippon Shokuhin Kagaku Kogaku Kaishi. 47(7) : 523-528.10.3136/nskkk.47.523
- Zhou, Z., K. Robards, S. Helliwell, and C. Blanchard. 2001. Ageing of stored rice: changes in chemical and physical attributes. Journal of Cereal Science. 33 : 1-15.
- Zhou, Z., X. Wang, X. Si, C. Blanchard, and P. Strappe. 2015. The ageing mechanism of stored rice: A concept model from the past to the present. Journal of Stored Products Research. 64 : 80-87.10.1016/j.jspr.2015.09.004
- Journal Title :The Korean Journal of Crop Science
- Volume : 63
- No :2
- Pages :98-105
- Received Date :2018. 01. 09
- Accepted Date :2018. 03. 26