Skin Rupture Issues in Cooking Skin-On Poultry and Coating Products

In poultry processing, when products with skin are steamed or baked, and battered chicken pieces and tempura-style products are prepared, there are frequent occurrences of bubbling, rupturing, and loss of coating. This increases the rate of defective products and troubles many R&D and production personnel. So, how does this phenomenon occur?

Regardless of whether using tunnel steamers, spiral ovens, steam cabinets, ovens, or smokehouses, the heating equipment operates by convection heating. The parameters that need to be controlled in convection heating mainly include temperature, humidity (or steam saturation), airflow speed, and time. In order to achieve an attractive color, aroma, and flavor, and to improve yield, food companies often strive to shorten heating time by increasing heating temperature, not realizing that excessive steaming temperatures can lead to product rupture!

Everyone has experience boiling water: when the water reaches 92 degrees Celsius, it starts to form bubbles. At this point, the surface tension of the water is at its maximum, leading to bubble tension.

When the product is steamed, moisture within the food begins to escape, and moisture in the airflow condenses on the product surface, transferring heat inward. As the temperature of the food gradually increases and reaches 92 degrees, inter-layer tension forms between different layers due to the bubble tension, which is the main culprit behind skin rupture and coating loss!

Remember this point, and it becomes much easier to set the processing parameters for the equipment: ensure that the steaming or baking temperature and time are appropriate so that the surface steaming temperature (note: the surface steaming temperature is different from the oven temperature) does not exceed 92 degrees. This will prevent the development of inter-layer tension and, consequently, skin rupture.

How can this be controlled? It relies on both experience and scientific instruments; simply controlling a single parameter will not suffice. However, it should be noted that through process control, it is entirely possible to achieve perfect product quality!

If anyone has any good tips, please share them, and we can discuss and share insights.