Nut roasting applies controlled dry heat or oil to kernels to develop flavour, colour and texture while reducing moisture, and it accelerates oxidation, making shelf-life management more critical than for raw kernels.
In trade practice
Roasting parameters including temperature, time and airflow are defined in a roasting profile agreed with the customer, and colour is monitored using a colorimeter or visual reference scale. Roasted nuts require packaging with low oxygen permeability, and nitrogen flushing or oxygen absorbers are commonly used to extend shelf life. A frequent error is applying raw-kernel shelf-life assumptions to roasted product, leading to rancidity complaints before the stated best-before date.
In a specification
A roasting specification states target colour values, maximum moisture after roasting, roast degree category such as light, medium or dark, and any limits on free fatty acid or peroxide value at point of dispatch.