Optimize the adhesion of salt onto potato chips.

To gain consumer loyalty in a competitive snack food market, companies need to consistently produce well-coated potato chip products. Toward this end, it is important to understand how seasoning adheres to food surfaces so that we can improve the process involved in coating snacks. The adhesion of salt onto potato chips affects the product's flavor and impacts whether consumers will purchase the product.

Scientists at The Ohio State University examined a number of factors that could impact how salt adheres to potato chips: surface oil content (SOC), chip temperature, the time between frying and coating the product, oil composition, salt particle size, salt crystal shape and the use of electrostatics. It appears that the best adhesion conditions would involve applying small salt particles to an oily surface.

Investigators produced chips with three different SOC levels--high, low and no SOC. Patting fried chips with a paper towel reduced SOC levels. Extracting fried chips with hexane removed SOC. Baking fried chips increased chip temperature.

The researchers fried chips in soybean, olive, corn, peanut and coconut oils to study the effects of oil composition. They nonelectrostatically coated NaCl crystals of five different particle sizes and three different shapes onto the chips. Using a powder applicator, five different sizes of salt were electrostatically applied onto all SOC chips. A feeder, which simulates a moving conveyor belt used in commercial settings, removed the salt.

Chips with high SOC had the highest adhesion of salt, making SOC the most dominant factor. Increasing chip temperature increased SOC and adhesion activity. Increasing the time between frying and coating the chip reduced the extent of adhesion for low-SOC level chips, but did not affect high- and non-SOC chips. Changing oil composition did not change adhesion values.

Increasing the size of the salt particles decreased the extent of adhesion on all SOC chips. The effect of salt size was most evident in lower SOC chips. The larger-shaped crystals adhered less extensively than smaller-shaped crystals on all SOC chips, except for large cubic-shaped crystals on low-SOC chips. For chips with low SOC levels or none at all, cubic-shaped crystals gave the best adhesion properties. Electrostatic coating improved adhesion values for all salt sizes.

Further information. Sheryl Barringer, Department of Food Science and Technology, The Ohio State University, 317 Parker Food Science and Technology Building, 2015 Fyffe Rd., Columbus, OH 43210; phone: 614-688-3642; fax: 614-292-0218; email: barringer.11@osu.edu.