Preliminary Study of Ultrasonic Structural Quality Control of Swiss-Type Cheese

Emmental-type cheese ripening process (Kosikowski and Mistry, 1997; Fröhlich-Wyder and Bachmann, 2004) with typical ripening times applied in Finland. Panels A–C depict potential process phases for nondestructive monitoring.

Schematics of the measurement set-up.

Two different images on the same cheese sample interior obtained with the ultrasonic method (top) and reconstructed from the photographed slices (bottom). Corresponding structural components (I: crack, II: two cheese-eyes, III: one cheese-eye) are indicated in both figures.

Two slices of the Emmental cheese sample used in ultrasonic and optical image studies.

Ultrasonic reflections (1MHz, 100 times averaged) from different structural elements found in 2 Swiss cheese samples (20cm ×10cm ×10cm). Dotted circles and arrows indicate the measured structural elements and their corresponding radio-frequency signals. Characteristic signals from a crack (I) and an eye (II) in a 12-mo-old sample (left). Whey nest structure (III) in a 4-mo-old sample (right).