Pre-Treatment Methods for Freeze Drying

Pretreatment is optional, but it can improve results for certain foods. Fruits that brown easily—like apples and bananas—can benefit from an acid dip. A brief soak in lemon juice or a mild citric acid solution slows browning and improves appearance. Many vegetables benefit from blanching. Blanching is a short boil followed by rapid cooling. It slows enzymes that can degrade flavor and color during storage. Pretreatment is not always necessary, but it is useful when appearance, color, or long-term flavor stability is important.