Barley for Food and Health: Science, Technology, and Products

140 EVALUATION OF FOOD PRODUCT QUALITY
includes cooking in distilled water, after which the pasta is drained and weighed.
The cooking water is then evaporated and the dried residue is weighed, which
should not exceed 7 to 8% of the dry weight. The firmness of cooked pasta is
measured with an instrument such as the Instron Universal Testing Instrument
(Canton, Massachusetts), following Approved Method 66-50 (AACC 2000). This
procedure measures and records the work required to cut through a piece of pasta.
Another evaluation of pasta is sample scoring, a statistical tabulation of at least
11 quality factors, with emphasis on protein content, color, and firmness (Dick
and Youngs 1988).
In Canada (Matsuo 1988), pasta is evaluated similarly, although recent research
studies have included Asian noodles with some specific evaluations for color.
Images of raw noodle sheets were scanned for parameters of noodle speck size
and delta-grey. Delta-grey defines the minimum color difference for identification
of a discolored speck, and speck size is the minimum threshold size that
a speck must exceed to be detected (Hatcher et al. 2005). These authors also
utilized optimum cook time as a standardization for trials, and additional variations
of texture measurement, maximum cutting stress, texture profile analysis,
and stress relaxation tests using a texture analyzer (Texture Technologies Corp.,
Scarsdale, New York). Dexter et al. (2005) contributed extensive experience and
knowledge to pasta quality evaluations, citing procedures of the Canadian Grain
Commission (CGC, 2003). Additional instrumental techniques were reported by
Sissons et al. (2005). Extensive pasta evaluation techniques have also been developed
in Europe, particularly in Italy, the birthplace of spaghetti as we know it
(Cubadda 1988).
SENSORY EVALUATION
Subjective or sensory food evaluation is essential in most food studies because it
answers the important questions of how a food actually looks, smells, tastes, and
feels in the mouth. In other words, “the proof of the pudding is in the eating”
(M. de Cervantes, 1547–1616). Certainly, the inclusion of barley ingredients into
a standard food product mandates the employment of sensory testing because
certain barley varieties can introduce different appearance, texture, and taste,
partly due to the presence of fibers such as arabinoxylans and β-glucans and
partly due to phenolic compounds. Although sensory tests may appear simple
and nonscientific, they are actually difficult to accomplish because they depend
on human judgment, which can be affected by many factors. The Institute of Food
Technology (IFT) has provided the following definition: “Sensory evaluation is
a scientific discipline used to evoke, measure, analyze and interpret reactions to
those characteristics of foods and materials as they are perceived by the senses
of sight, smell, taste, touch and hearing” (IFT, Chicago, Illinois). Preparation
for the tests and presentation of the products must be carefully planned and the
environment standardized. We provide only a very brief description of the basics
of sensory testing here. If such tests are to be undertaken, a detailed reference such