Cereals processing technology

86 Cereals processing technology
Specialty US rices
Newrex/Rexmont-type rice represents the first major improvement in the
inherent cooking, eating, and processing quality of southern long-grain
varieties. The types were developed to satisfy industry’s need for drier,
fluffier table rice combined with improved canning stability. The Newrex/
Rexmont type is the forerunner of these improved types. The Della types
(Table 5.3) are scented (aromatic) long-grain produced in limited amounts as
specialty rice. They give off an aroma on cooking like that of roasted nuts and
have flavorful nutty tastes. Jasmine aromatic (scented) rices are recently
introduced types similar in taste and aroma to Della, but they are softer and
more clingy in texture. Jasmine types are characterized by low amylose and
low gelatinization temperature like the Toro and conventional short- and
medium-grain types.
Toro types are specialty rice produced in limited amounts for specific
markets. They have the grain size and shape of other US long-grains but possess
cooking and eating behaviors of US short- and medium-grain types. Toroquality
rice is used by segments of the population who prefer the clingy cooked
texture of short- and medium-grains in long-grain types. Toro is characterized as
a low-gelatinizing, low-amylose type like those of conventional US short- and
medium-grain varieties.
Specialty waxy Mochi Gome-type short-grain rice varieties are produced in
limited quantities in California. They are characterized by opaque endosperms
of virtually all amylopectin starch, low gelatinization temperatures, and
relatively low amylographic peak, hot paste and cool paste viscosities. Waxy
rice is produced primarily for specialty products, and numerous commercial
product formulations, including rice cakes, crackers, sauces, gravies, salad
dressing, desserts, and batter dips for fried foods.
5.2.3 US rice standards and grades
United States Standards for Rice (USDA 1989) 31 and Rice Inspection Handbook
(USDA 1982 with changes 1982–1990) 30 provide a means for the orderly
marketing of rough rice, brown rice for processing, and milled rice by grades.
Although grades are useful tools, they do not provide a sufficiently refined
classification of rice to satisfy all quality requirements of the rice industry.
Factors involved in establishing rice grades include moisture content, color,
degree of milling, dockage (impurities), damaged kernels, odors, red rice, and
seeds or kernels of any plant other than rice.
Moisture content
Rough-rice moisture contents of 13% must be harvested at recommended
moisture contents (about 23%), dried carefully to safe storage moisture levels,
and stored and milled under moisture conditions suitable for maximum milling
yield. Methods for measuring moisture content vary widely. Air-oven, or
vacuum-oven, procedures are basic methods for determining moisture in rice.