Stable Micro Systems has launched a Rice Extrusion Rig which the company says conforms with the newly-released International Standard (ISO 11747) for rice testing. For the first time, it said, growers, processors and food manufacturers can objectively and accurately analyse the resistance to extrusion of rice samples, enabling them to select the cultivars which satisfy both their own textural requirements and the demands of customers and consumers.
According to Stable Micro Systems, as well as being a basic and widely consumed foodstuff in its own right, rice is increasingly popular as a component of processed and convenience foods - but with over 1,000 varieties, identifying the one with optimal amylose content, gel consistency and gelling temperature to match the desired eating texture can be difficult.
Stable Micro Systems says that its new rig provides a simple, quick, accurate and economical method for measuring the eating qualities of rice with additional design features specifically focused on making the testing cell more quickly removable and replaceable between tests. After cooking, a sample of the rice is placed in the rig’s testing cell. It is pushed down by a plunger of similar cross-section to the cell, compressing the rice and extruding it through holes in the base extrusion plate.
Resistance to extrusion is measured as the ease of pushing the cooked rice through the perforated plate using compression and shear. It is calculated automatically and recorded as mean force, in kg/cm2.
“Food palatability is determined by many factors,” said Jo Smewing, applications manager at Stable Micro Systems, “and texture is the one that can be difficult to measure objectively and repeatably. The challenge is magnified when we take into account regional preferences. In the Middle East and south Asia, dry and flaky rice varieties are preferred. But in Japan, the Republic of Korea and northern China, consumers opt for moist and sticky. Being able to complement sensory testing with instrumental evaluation methods means the industry can now perfect aroma, appearance, taste and texture, all of which are critical to consumer acceptance.”
