Effect of temperature and time immersion of stage soaking on color grains of upland rice parboiled cultivars

Flávia Araújo Fonseca, Manoel Soares Soares Júnior, Márcio Caliari, Diva Mendonça Garcia, Priscila Zaczuk Bassinelo, Eduardo Eifert Costa

Abstract


The parboiling is the hydrothermal treatment of paddy before processing. The objective of  this study was to evaluate the influence of the temperature and immersion time step of soaking (independent variables) on the color of the grain parboiled (dependent variable) cultivars of upland rice (BRS Primavera and BRS Sertaneja). A central composite rotational design (DCCR) was used, which includes a 22 full factorial, three replicates at the center point and four axial points, making eleven treatments. It was considered for the selection of hydrothermal conditions to be studied, the criterion of water absorption in the age group from 28% - 32%. In extreme conditions of soaking (high temperature and immersion time) was observed in general that the grains of parboiled rice had higher color difference for the samples of grains of white rice. Therefore, the use of temperatures below 65 °C during the soaking tend to have grains with milder browning. After parboiling under different conditions of temperature and time of soaking, the change of color (?E*) was greater in cv. BRS Sertaneja. It is possible to produce grains with different shades, depending on the conditions used. The choice will depend on the application that is intended or products in wich the rice will be employed.


Keywords


Oryza sativa L.; Hydrothermal treatment; Physical analysis



DOI: http://dx.doi.org/10.5433/1679-0359.2011v32n1p221

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional