Non-contact ultrasonic quality measurements of food products

This paper describes the application of a non-contact ultrasonic system to food inspection, using electrostatic transducers and signal processing techniques. The system, which operates in through-transmission mode, is used to detect physiochemical changes and density variations in food. One application is to monitor coagulation processes, caused by destabilization in milk-based products. It is shown that the amplitude of the signal varies with time after the pH of such samples was lowered, resulting in destabilisation. Various types of samples of different pH values were used in order to illustrate that the air-coupled system was sensitive to such changes. Non-contact imaging has also been performed to follow this process, during which gel formation could be identified. In addition, changes in oil properties due to temperature variations have also been measured using the non-contact system. The measurements can be achieved without contact to the test samples, and thus has the potential for the rapid inspection of various types of food products.

[1]  R. Dearden.  AUTOMATIC X-RAY INSPECTION FOR THE FOOD INDUSTRY , 1996 .

[2]  J. Bows,et al.  MRI phase mapping of temperature distributions induced in food by microwave heating. , 2000, Magnetic resonance imaging.

[3]  Charles E. Cook,et al.  Pulse Compression-Key to More Efficient Radar Transmission , 1960, Proceedings of the IRE.

[4]  Richard E. Challis,et al.  Monitoring the crystallization from solution of a reactive dye by ultrasound , 2000 .

[5]  B. Senge,et al.  INVESTIGATIONS INTO THE COMBINED ENZYMATIC AND LACTIC ACID MILK COAGULATION , 1999 .

[6]  G. Nassar,et al.  Monitoring of milk gelation using a low-frequency ultrasonic technique , 2001 .

[7]  N. Berridge.  488. An improved method of observing the clotting of milk containing rennin , 1952, Journal of Dairy Research.

[8]  S. Brandão,et al.  Predicting the Cutting Time of Coagulating Milk for Cheese Production Using a Heated Thermistor , 1999 .

[9]  C. Javanaud,et al.  Applications of ultrasound to food systems , 1988 .

[10]  Kiyotaka Sato,et al.  Ultrasonic velocity measurement of crystallization rates of palm oil in oil-water emulsions , 1997 .

[11]  M Akhnak,et al.  Ultrasonic measurement of milk coagulation time , 2001 .

[12]  F. A. Payne,et al.  Automatic Control of Coagulum Cutting in Cheese Manufacturing , 1995 .

[13]  Dominique Durand,et al.  Ultrasonic study of milk clotting , 1994 .

[14]  C. L. Hicks,et al.  Predicting cutting and clotting time of coagulating goat's milk using diffuse reflectance: effect of pH, temperature and enzyme concentration. , 2000 .

[15]  Navalgund Rao,et al.  Investigation of a pulse compression technique for medical ultrasound: a simulation study , 1994, Medical and Biological Engineering and Computing.

[16]  J. Maubois,et al.  COMPUTERIZED VISCOMETRIC METHOD FOR STUDYING RENNET COAGULUATION OF MILK , 1987 .

[17]  Y. Iizuka.  High signal-to-noise ratio ultrasonic testing system using chirp pulse compression , 1998 .

[18]  Chyung Ay,et al.  Evaluating milk coagulation with ultrasonics , 1999 .

[19]  V. Ermolov,et al.  Analog pulse compression system for real-time ultrasonic non-destructive testing , 1996 .

[20]  Emmanuel P. Papadakis,et al.  5 – Ultrasonic Velocity and Attenuation: Measurement Methods with Scientific and Industrial Applications , 1976 .

[21]  D. A. Hutchins,et al.  Preliminary studies of a novel air-coupled ultrasonic inspection system for food containers , 2002 .

[22]  U. Cogan,et al.  Determination of Clotting Power of Milk Clotting Enzymes , 1976 .

[23]  Judith Ann Bamberger,et al.  Non-invasive characterization of fluid foodstuffs based on ultrasonic measurements , 2004 .

[24]  David W. Penman.  Automated x-ray detection of contaminants in continuous food streams , 1996, Other Conferences.

[25]  E. R. Davies,et al.  Texture analysis for foreign object detection using a single layer neural network , 1994, Proceedings of 1994 IEEE International Conference on Neural Networks (ICNN'94).

[26]  D. Julian McClements,et al.  Advances in the application of ultrasound in food analysis and processing , 1995 .

[27]  D. Mcclements,et al.  Effect of temperature on the ultrasonic properties of oil-in-water emulsions , 1998 .

[28]  D. Gallant,et al.  Fluorescence Spectroscopy Investigation of Acid-or Rennet-Induced Coagulation of Milk , 1999 .

[29]  David A. Hutchins,et al.  Field characterization of an air-coupled micromachined ultrasonic capacitance transducer , 1997 .

[30]  M. Jordán,et al.  Viscosity changes during rennet coagulation of Murciano‐Granadina goat milk , 1999 .

[31]  Navalgund Rao,et al.  Medical ultrasound imaging using pulse compression , 1993 .

[32]  D. Schindel,et al.  The use of broadband acoustic transducers and pulse-compression techniques for air-coupled ultrasonic imaging. , 2001, Ultrasonics.

[33]  David A. Hutchins,et al.  Advances in ultrasonic electrostatic transduction , 1998 .

[34]  J. B Hull,et al.  Controlling waste in food processing using ultrasound level monitoring technology. , 1995 .

[35]  S. Gunasekaran,et al.  Evaluating milk coagualtion with ultrasonics : Ultrasonic applications in the food industry , 1994 .

[36]  Otman Basir,et al.  Detection of metal, glass and plastic pieces in bottled beverages using ultrasound , 2003 .