Juliano et al. - 1993 - Grain Quality Evaluation of World Rices

Introduction
D
ata bases are available for grain characteristics of market
samples in some rice-consuming countries (RCMD 1987, 1989;
Rivenburgh 1961, Simpson et al 1965) and of germplasm
collections (IITA 1985, IRRI 1990). Juliano and Pascual (1980) have the
only data base for rice quality in some countries. In this book, all
countries producing 0.1% or more of the world's rice are included
along with quality information (when available), rice production data,
and per capita milled rice supply from FAO.
Grain quality is second only to yield potential as the major
breeding objective (Table 1) for the 11 countries responding to a 1990
survey of national rice programs (Juliano and Duff 1991). Apparent
amylose content is the major factor influencing cooking and eating
quality of milled rice. Alkali spreading value and GC can distinguish
rices with similar AC, particularly waxy and high-amylose rices
(Table 2).
Amylograph pasting viscosity indicates changes in texture during
cooking. Many factors affect peak viscosity, but Amylograph setback
and consistency relate to cooked rice hardening during cooling.
Cooked rice hardness and stickiness are also important grain quality
indicators. Milled rice length and width help to completely characterize
grain size and shape.
Data for each sample are alphabetically listed and ordered chronologically
for each variety. Variety names are cross-referenced when
listed under an equivalent name in the same or a different country.
Water regime data (upland, irrigated, deepwater, rainfed lowland,
tidal wetlands, and hydromorphic) are included when available.
Only 4% of total rice production enters the world market. Some
national programs have considered exporting their excess production.
They often do not fully understand, however, the competitiveness of
the world market and stringent quality requirements, particularly on
contaminants (Efferson 1985). In Hongkong, for example, consumers