Cereals processing technology

8.3 Recent trends and technology developments
Breakfast cereals 163
The 1990s has seen voluminous technical developments brought into RTE
manufacturing processes. It will be easiest to examine each unit operation of an
RTE process and highlight some of these outstanding developments. 6 In all
truthfulness most of these have been driven by the desire to reduce labor costs,
lower human error, elevate the quality of the work environment, increase output
of in-specification finished product, i.e. better product quality control, and
improve safety in the workplace. The driving innovation of all of these changes
in how much technical hardware is now used in cereal manufacturing has been
the widespread adaptation of the microchip. It has been to cereal processing
what radio development in the 1920s was to cereal marketing.
8.3.1 Developments in weighing
The first step in the cereal process is the measurement of the ingredient
quantities to be used in each recipe. Measurements of bulk dry ingredients can
now be taken directly at the storage silos if they are mounted with load cells.
Batch usages can be taken, and in addition inventory monitoring is available so
that reorder times are easily readable. Likewise liquid ingredient measurements
for bulk ingredients for both batch and continuous operations can be displayed
accurately using coriolis flow meters.
In batching major dry ingredients, the use of weighbelt feeders is common.
Screw feeders are also commonly used, both volumetric for very uniform bulk
density materials, and gravimetric for materials with variable flow characteristics
or bulk density. Gravimetric screw feeders are mounted on load cells, or a
load cell platform, and flow is sensed via loss-in-weight from the feeder hopper.
This same loss-in-weight principle has been applied successfully to the delivery
of liquids. Uniformity of delivery is sensed by the load cell supporting the liquid
reservoir tank. The weight signal is used to drive the delivery pump speed either
slower or faster as the weigh signal calls for it. When the reservoir empties to a
‘low level’ position, the pump locks onto its last set point speed while the
reservoir is refilled. This delivery while refilling is volumetric, but the time
needed for refill is so short in overall operating time, it makes no observable
changes in finished product quality.
The importance of these electronic upgrades in ingredient weigh systems
cannot be overstated. Uniformity of finished product is first and foremost
dependent on uniform weighing of each and every ingredient used in the recipe.
After mastering techniques to measure accurately bulk dry and liquid
ingredients, much remained to be accomplished in the automated measurement
of minor ingredients – both solid and liquid. These areas have now both been
successfully and accurately brought to high levels of microprocessor
sophistication. Granted, many of the units operate sequentially – one ingredient
measurement after another – but they are accurate.