For more than two decades, snack food producers have been enjoying the benefits of on-machine seasoning (OMS), where seasoning is applied at each packing station for potato chips.
OMS allows for longer runtimes, reduced production stoppages, more accurate seasoning control, easier cleaning protocols, and improved SKU control of flavour variations and bag sizes.
With the latest technology, OMS is able to be used for non-PC products, including baked snacks, corn tortillas, and other products. These new applications sometimes require an application of oil for seasoning adherence. Usually, this is easily done; however, it needs to be done correctly for the product to achieve full capability and quality.
This article addresses the factors of temperature and time and the necessary setup for these process requirements to work optimally.
Temperature
If a product is too hot, the oil will be absorbed too rapidly. While this may be beneficial for keeping cooling conveyors clean and for achieving overall snack flavour, if the oil is not on the product’s surface, it is ineffective to as an adhesive agent.
When baked products are oiled at the end of the oven segment, the oil is absorbed too quickly. Likewise, when tortilla chips are baked then fried in oil, these hot applications still leave the product with inadequate surface oil for seasoning adhesion.
In most snack products, oil and fat are part of the flavour structure, and they also can amplify, prolong, and enhance other flavours. If the flavour demands a certain level of oil, one solution is choosing to apply some oil to the product when hot and the remainder of the oil when cool to produce a well-structured result with the opportunity for great flavour pickup.
Timing
Product temperature translates directly with timing. At the exit of its process, whether baked or fried, the product starts cooling. The oil absorption rate slows as the temperature drops (e.g., crackers can lose 10°C in 20 seconds, about 30’ on a conveyor).
Fundamentally, the bigger the delta T between the product and the oil, the faster the absorption rate.
Therefore, for adhesive purposes, the oil must be applied when the product has cooled sufficiently so the oil absorption rate is slow enough so that an adequate amount remains on the surface. Typically, oil needs to be at a high temperature in order to be sprayed to achieve the best distribution across the product.
If the product is significantly colder than the oil, then the absorption can be usually slowed enough to be effective.
There are three positions where these later stage oils or other liquid mediums could be applied, whether for adhesive or for flavour:
- In-kitchen application — oil and seasoning are applied in a large single seasoning drum located in the processing kitchen. Oil is applied at the front end with a seasoning application at the back end. This is a bulk application process and does not allow for the flexibility enabled by on-machine seasoning. Large capacity lines can be divided into two or three seasoning drums with different flavours, which then require duplication of the distribution conveyors.
- Full OMS application — oil and seasoning applied in each on-machine seasoning drum. A single distribution set of conveyors feeding each OMS station according to the requirements of the bagger at that position. Although enabling the OMS flexibility, oiling at each drum adds cost and complexity that may be useful for the wet flavour to complement the dry seasoning but is excessive for the purpose as an adhesive oil application.
- Single oiling drum & OMS — application of oil in a single suitably smaller drum, oil is applied in bulk to the product; after distribution, seasoning is applied OMS style. This design enables all the benefits of OMS without the complexity noted above. The location where the oiling drum is determined by the product temperature delta from the oil temperature and the rate of absorption of the product. This application works by allowing the product to be efficiently oiled when cool, either in the kitchen or on the mezzanine and before distribution to OMS packaging stations.
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