WSU Apple Breeding Program Picks Unique Taste-Testing Device

An apple’s crispness is rated among its most important qualities by consumers, but the apple industry has not yet established a reliable automated method for measuring fruit crispness, instead relying primarily on subjective and labor-intensive taste-testing. But, new research has confirmed the capabilities of a unique texture-testing instrument that could change the way apple crispness is rated.

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Researchers with the Washington State University Apple Breeding Program (WABP), led by associate professor Kate Evans, compared the sensory attributes of a variety of apples, rated by an expert taste-testing panel, with measurements obtained by the Mohr MDT-1 penetrometer. According to their report, the researchers found a significant correlation between the MDT-1’s crispness measurements and the apples’ crispness and overall eating quality.

The MDT-1 is a next-generation replacement for the hand-operated Magness-Taylor penetrometer the industry has used for decades to measure fruit firmness, and the researchers conclude that MDT-1’s unique measurements are likely more informative than other penetrometer tests or acoustic resonance techniques. The report also says that the WABP intends to use the MDT-1’s measurements to reduce the need for taste-testing as they develop new apple varieties.

“Think of the MDT-1’s plunger as a mechanical tooth,” says Brandt Mohr, Mohr’s chief technologist. “The MDT-1 measures the energy released by the crunch of the apple as the plunger advances in a way that is repeatable and operator-independent. Fruit firmness alone is not adequate, because a firm apple is not necessarily a crisp apple.”

For more information on the MDT-1, go to www.mohr-engineering.com.