Animal Feed

Moisture Levels Make the Difference

In pet food manufacturing, the prime concerns are with the quality of the materials that go into the product. Chief among these may be mycotoxins, a fungi grown on grains during stresses during harvest or less than ideal grain storage where high temperature and moisture contribute to the fungi growth. Medicated feeds such as those where water based liquid antibiotics are added should also be closely controlled.

Accurate moisture measurement of the actual percent moisture content in the individual ingredients as well as any added medications, vitamins, minerals, etc. are critical for production and safety. Typically, water content is determined by loss of weight on drying (also called oven or gravimetric drying). However, this method leaves much to be desired in terms of accuracy. Because there are so many differences between various types of oven dryers and the specifications that each dryer depends on is different given sample size, temperature, and length of time the sample is in the dryer, it’s incredibly difficult to get a consistently accurate measurement this way.

The entire process of gravimetric drying can negatively impact pet food manufacturers’ bottom line in a serious way. Because the moisture results are often up to an hour late getting back to the process operator, not much can be done to make the appropriate adjustments – and that doesn’t even account for the product that may have been produced within that time frame. A failed moisture test with this method may result in product holds, rework (and associated labor) or even complete disposal, all of which costs you time and money.

Hands-Off Moisture Analysis With Incredible Accuracy

Moisture measurement is perhaps the most widely used test in the agricultural sector. It’s important for many reasons other than generating proper product quality. Excess water can contribute to product spoilage (fungi); water is heavy (8 pounds per gallon) and must be considered when grain is bought and sold; water adds weight when shipped; too much water would dilute other beneficial product constituents such as vitamins, minerals, proteins, etc.

When getting your moisture analysis right impacts your plant on such a large scale, we’re here to make it easy. We offer two types of moisture meters for the pet food processing industry: The Model MCPC, an RF (radio frequency) device used in the laboratory for instantaneous, non-destructive moisture measurement, and our NIR device. Our RF Probe is also used for on line moisture measurement in grain silos and storage facilities. NIR is used where non contact is needed and the product is less than about 0.5 inch or so in diameter.

Pet food applications require real time moisture measurement instrumentation with the ability to adjust process variables with little or no operator interface at a relatively quick pace to avoid loss of product that would otherwise not meet specs.

There are three primary types of pet foods: Dried kibble, semi-moist, and wet or canned. Kibble is by far the best selling pet food. Since it has a moisture content of about 10%, this provides the crunchy texture to the food and gives the scrapping action that helps to clean the teeth. Semi-moist pet food has a moisture range of about 60-65% and is typically the most expensive of the pet food types. It is sealed in serving packets that keep the food from drying out. Wet pet food has 75-78% moisture content and is usually fed to older pets that may have dental issues. Other less popular type of pet foods are: Raw, dehydrated, home prepared, and freeze-dried.

Wet pet food is usually not a large user of on line moisture meters since the product has such a high moisture content. Kibble and semi-moist foods however, do require the use of some type of moisture meter in order to assure product quality. Typical quality concerns are texture, color, particle size, nutritional quality, shelf life, etc. Finna Sensors offers its newest infrared (NIR) on line, continuous moisture meter, the OMNIR, to provide operational convenience to the pet food industry. Real time moisture measurement allows quick adjustments to process variables such as dryer temperature and flow rate thereby avoiding out of spec product that may result in product recycle or reject, mold or fungi growth, out of weight tolerance, overtime wages for rework, or even product scrap. The OMNIR moisture system offers real time feedback output for closed loop dryer control to alleviate these manufacturing difficulties.