Process Sensors Corporation

Potato Chip Moisture and Oil

Potato Chips

Potato Chip Moisture & Oil On-line Measurement

With billions of people enjoying savory snacks every day, it is no surprise that it is a $94 billion industry. Potato, corn and other snack chips are the most popular snacks and come in a variety of types and flavors.

Potato chips and other snack foods are often cooked in fryers where hot cooking oil removes free moisture in the chips as they cook. Frying is usually done in either a continuous process or in a batch kettle. Corn, multigrain chips and vegetables are fried in a process like the potato chips, but they also receive an additional toasting process not required for potato chips. The ending moisture of the food is critical to the texture, quality, and shelf life of the product. 

Potato Chip Manufacturing Process

Potato Preparation

Foreign debris, decaying potatoes and dirt are removed in the first stage of the process. The potatoes are then washed and peeled. High pressure water is used to cut the potatoes into the desired thickness and remove starch from the slices. Surface moisture needs to be minimized as much as possible prior to frying and it is removed by a variety of methods such as compressed air, rotating drum, or heated air.    

Frying Operation

The chips are fried either in a kettle batch process where they are time cooked, or in a continuous process, moving through the fryer on a continuous mesh belt. Each manufacturer has their preferred process and also their preferred oil(s) for desired taste and temperature including corn, peanut, cottonseed, soybean and canola oils.   

Seasoning and Packaging

Chips can be seasoned with a wide variety of flavors using oil and emulsion sprays, solid coatings or other processes. The seasoning operation uses a rotating drum or vibrating conveyor process to ensure consistent coating of the seasoning. The chips are then packaged by weight for shipment.   

Quality Parameters and Measuring Points

Moisture Measurements:  Potato Chip moisture is usually between 1 and 3.5% at the fryer exit depending on chip thickness and potato type. A Process Sensors Corporation (PSC) Near Infrared (NIR) sensor at the fryer exit is recommended to ensure process control. Chip moisture is also measured at the seasoning drum exit prior to final packaging to ensure flavor, freshness and shelf life.   

Oil Measurements: Oil content is usually between 25 and 35% and is generally dependent upon the moisture displaced in the process. Oil content impacts product flavor and is measured using the same NIR sensor that measures moisture at the fryer exit.  

Potato Chip Moisture and Fat Measurement

A PSC MCT-466SF (NIR) sensor is typically mounted within 6 to 16” of the product and a few meters after the fryer exit, to allow for airborne steam oil emulsion to dissipate. The stainless-steel housing and IP-65 rating of the sensor ensure reliable online operation and washdown compatibility.

The QuikCheck (NIR) benchtop analyzer may also be used either in the laboratory or at-line for quick, accurate and reliable samples testing.  

Value and Quality

Incoming potatoes vary significantly in moisture content and composition. Measurement of moisture and oil at the fryer exit with an NIR sensor from Process Sensors Corporation allows automatic adjustment of fryer temperature and or belt speed to remove the proper amount of moisture producing high quality, consistent chips. This also minimizes the cooking oil and energy used, saving the chip producer money and optimizing efficiency.  

Further analysis of the product after seasoning with an MCT466-SF or QuikCheck ensures a consistent product quality before packaging. This will extend shelf life and ensure that the final product meets the nutritional label specifications on the package, as well as the expectation of the consumer for a consistent product.  

To learn more about how we can optimize your potato chip production, please fill out the contact form below.  

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