Resumen de Biometric characteristics of rice cultivars

Tânia Santos, Diogo Lemos, Raquel P. F. Guiné, Paula R. Correia

• English

  The objective of this work was to evaluate the grain biometric characteristics of 62 rice cultivars, which cover Indica and Japonica subspecies, and different types of commercial rice like, Agulha (Indica rice cultivars), Carolino (Japonica cultivars), aromatic (basmati and thai), integral rice, risotto, glutinous (waxy), wild and parboiled rice. It was noticed that for the same group type of rice there are a great variance. Generally, the Agulha, Aromatic and Integral rices commercialized in Portuguese trade are long (length high than 6 mm and length/width ratio higher than 3) and risotto cultivars are medium size. The two studied glutinous rice cultivars presented one cultivar long and other cultivar round (length lower than 5 mm and length/width ratio lower than 1.9). All rice cultivars presented high values of white vitreous, total whiteness, and low percentage of chalky area, presenting a crystalline and translucent aspect, but there is an exception to integral rice cultivars due to absence of polish operation during the milling process and for parboiled rice cultivars due to the effects of parboiled treatment. Moreover the vitreous percentage was also high. There was a strong correlation between the white vitreous values and total whiteness.

• português

  O objetivo deste trabalho foi avaliar as características biométricas de 62 cultivares de arroz, pertencentes às subespécies Indica e Japónica, sendo comercializados diferentes tipos, como é o caso do Agulha, Carolino, Aromático, Integral, Risotto, Selvagem e o arroz vaporizado. Verificou-se que para o mesmo tipo de arroz existiram grandes diferenças. De um modo geral o arroz Agulha, Carolino, Aromático e Integral comercializados em Portugal são longos. No caso do arroz Glutinoso uma das cultivares é longa e a outra é redonda (comprimento menor que 5 mm e relação comprimento/ largura menor que 1.9). Todas as cultivares apresentaram valores elevados de brancura vítrea, brancura total, e uma pequena percentagem de área gessada.