64 Using the near infrared to measure moisture and oil in food.

D. JOY.

Moisture and oil measurements remain two of the biggest concerns for food manufacturers in which the product is extruded, granulated, dried, fried or baked. The need to maximize product yield and quality, meet specific moisture and oil targets set by government regulations, and energy-saving considerations are some reasons why moisture and oil control depends on the availability of an on-line sensor to provide a continuous and reliable signal relating to product moisture and oil. As a result, near-infrared reflectance (NIR) measurement increasingly has been adopted for accurate process control the past 25 years in a wide range of food applications, including snack foods and cereals. Today the technique is recognized as an extremely useful and powerful measurement technique. Recent developments in moisture measurements have eliminated sensitivity to particle size, minimized sensitivity to color, increased ability to compensate for pass height variation, and extended the measurement ranges of moisture and oil, while retaining calibration linearity. A recent innovation enables a simple one-point trim adjustment to calibrate the infrared sensor by the end-user. These factors have enormously in enhancing the reputation of the on-line measuring technique, by improving the measurement quality and simplicity of implementation and, more importantly, expanding the range of applications to include constituents that do not interact strongly with infrared light. Examples include the oil content in snack foods, as well as protein content in many food products.