Strategies for the ‘protection’ of fortifying nutrients in dairy-based powders: a critical review based on mechanisms behind chemical instability

Dairy-based powders, an important source of nutrition, often comprise base components that provide macro-nutrients and fortification with micro-nutrients delivered through specialist ingredients. A general belief is that the strategy for preserving the dairy-base, by drying, is insufficient for preserving specialist ingredients. Protective strategies beyond drying include external environmental controls, dry-blending, modified atmosphere packaging, active packaging, encapsulation, antioxidant addition, and selecting specific nutrient forms. In this review, these strategies are assessed while asking the questions: why do approaches work and could simpler approaches also work if the mechanistic requirements were met? Thus, this review critically and holistically assesses the links between nutrient protection approaches and proposed nutrient instability mechanisms. A conclusion was that while nutrients may suffer degradation eventually, what happens after a food becomes unpalatable is of little practical value and therefore focusing on achieving sensory shelf-life, using simple controls, often sufficiently protects nutrients without the requirement for specialised techniques.