To ensure no change in the shelf life of frosting after a vendor change, which characteristic is MOST important to test?

The most important characteristic to test to ensure no change in the shelf life of frosting after a vendor change is the water activity (Aw). Water activity is a measure of the amount of water available for microbial growth and chemical reactions in food products. Testing the Aw of the frosting is crucial because it directly influences the stability and safety of the product over time.

If the Aw is too high, it can lead to microbial growth, spoilage, and a reduced shelf life, regardless of changes in other ingredients. Therefore, maintaining consistent water activity levels is essential to ensuring that the shelf life remains unaffected by vendor changes.

While carbohydrate content, fat content, and pH can all impact the quality and stability of frosting, they are not as directly linked to microbial growth and spoilage as water activity is. Hence, focusing on Aw provides a clearer assurance of consistent shelf life across different formulations from a new vendor.